WO2018056204A1 - Si particle aggregates and method for producing same - Google Patents

Si particle aggregates and method for producing same Download PDF

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Publication number
WO2018056204A1
WO2018056204A1 PCT/JP2017/033436 JP2017033436W WO2018056204A1 WO 2018056204 A1 WO2018056204 A1 WO 2018056204A1 JP 2017033436 W JP2017033436 W JP 2017033436W WO 2018056204 A1 WO2018056204 A1 WO 2018056204A1
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Prior art keywords
powder
particle
flow
gas
particles
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PCT/JP2017/033436
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French (fr)
Japanese (ja)
Inventor
宏隆 曽根
尚 杉江
佑介 杉山
裕輔 山本
合田　信弘
井上　敏樹
隆行 渡邉
田中　学
拓也 影山
周平 吉田
大輔 岡元
建太郎 山野
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株式会社豊田自動織機
国立大学法人九州大学
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Priority to JP2018541040A priority Critical patent/JP6743159B2/en
Publication of WO2018056204A1 publication Critical patent/WO2018056204A1/en

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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B33/00—Silicon; Compounds thereof
    • C01B33/02—Silicon
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B33/00—Silicon; Compounds thereof
    • C01B33/02—Silicon
    • C01B33/021—Preparation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a novel Si particle, a method for producing the same, and a non-aqueous electrolyte secondary battery using the novel Si particle.
  • Si is used in various applications such as solar cell materials, secondary battery active material, and photoreceptor materials.
  • Patent Document 1 International Publication No. 2014/080608 synthesizes a layered silicon compound mainly composed of layered polysilane obtained by reacting CaSi 2 with an acid to remove Ca, A silicon material in which a layered silicon compound is heated at 300 ° C. or higher to release hydrogen and a lithium ion secondary battery including the silicon material as an active material is described.
  • the negative electrode active material expands and contracts with the insertion and extraction of lithium (Li) during charge and discharge.
  • Li lithium
  • the negative electrode active material expands and contracts, a load is applied to the binder that holds the negative electrode active material on the current collector.
  • the adhesion between the negative electrode active material and the current collector may be reduced, or the conductive path in the electrode may be destroyed.
  • the resistance of the electrode increases and the capacity of the battery may be reduced.
  • the negative electrode active material may be distorted due to repeated expansion and contraction, and may be refined and detached from the electrode.
  • the expansion and contraction of the negative electrode active material also affects the deterioration of the cycle characteristics of the battery.
  • the formation of fine particles of the silicon-based material has been studied.
  • gas atomization method in which gas is blown to molten Si flowing down from a nozzle to form fine droplets of molten Si, or molten Si is put into a dish-shaped disk that rotates at high speed, and centrifugal force is applied.
  • a rotating disk method that scatters droplets is known.
  • Patent Document 2 Japanese Patent Laid-Open No. 2005-320195 discloses a method for producing Si particles having a particle diameter of 10 ⁇ m to 50 ⁇ m by a rotating disk method.
  • Patent Document 2 discloses that a dispersion containing Si particles having a particle diameter of 10 ⁇ m to 50 ⁇ m manufactured by the rotating disk method is manufactured, and the operation is performed by pressing the dispersion and passing it through a small-diameter nozzle. It is disclosed to obtain nanometer-sized Si particles with a reduced diameter.
  • the present inventor puts raw material Si powder into the plasma, turns the raw material Si powder into a gas or liquid state, cools the outside of the plasma, and uses the extreme temperature difference between the inside and outside of the plasma to produce the product. It recalled that it was rapidly cooled to obtain Si particles.
  • the inventor has conducted intensive studies and introduced raw material Si powder into the plasma as an introduction flow, and a cooling gas that opposes the passage flow after the introduction flow has passed through the plasma. It was confirmed that a new form of Si particle combination was obtained by cooling with a flow. Further, it was confirmed that a carbon-containing film can be formed on the Si particle bonded body by bringing a carbon source gas into contact with Si during cooling.
  • a special carbon-containing film can be formed under conditions where the plasma output is 5 kW or more and less than 15 kW, or by specifying the supply position of the carbon source gas in the cooling gas.
  • this inventor manufactures the negative electrode which comprises Si particle
  • the Si particle bonded body of the present invention has Si particles and fibrous Si bonded to the Si particles, and the particle size of the Si particles is larger than the fiber diameter of the fibrous Si. .
  • FIG. 1 It is a schematic diagram of the Si particle combination of the present invention. It is a schematic diagram of a plasma generator.
  • 2 is a result of observation of a cross section of a powder of Example 1 by a scanning electron microscope (hereinafter, appropriately referred to as a cross section SEM). It is a cross-sectional SEM observation result in the magnification of 10 times of FIG. It is a cross-sectional SEM observation result in the magnification of 100 times of FIG. It is an observation result of the transmission electron microscope (hereinafter referred to as TEM as appropriate) of the powder of Example 1.
  • 3 is a particle size distribution diagram of Si particles of the powder of Example 1.
  • FIG. 10 is an observation result by electron energy loss spectroscopy (hereinafter referred to as EELS (Electron Energy-Loss Spectroscopy) as appropriate) of the fibrous Si 20 in FIG. It is a schematic diagram which shows the observation result of FIG.
  • XPS X-ray Photoelectron Spectroscopy
  • FIG. 5 shows the results of pyrolysis gas chromatography (Pyrolysis Gas Chromatography, hereinafter referred to as “Py-GC” as appropriate) of the coating films of the powder of Example 4, the powder of Reference Example 1, and the powder of Reference Example 2.
  • FIG. 4 is an XRD chart of measurement results of powders of Examples 1 to 4 and Example 6 by a powder X-ray diffraction method (hereinafter referred to as XRD as appropriate). It is a charging / discharging curve of the lithium ion secondary battery of Example A and Comparative Example A. It is a charging / discharging curve of the lithium ion secondary battery of Example B, Example C, and Example D. It is a graph which shows the relationship between the cycle number of the lithium ion secondary battery of Example B, Example C, and Example D, and a capacity
  • the numerical range “x to y” described in this specification includes the lower limit x and the upper limit y.
  • the numerical range can be configured by arbitrarily combining these upper limit value and lower limit value and the numerical values listed in the examples.
  • numerical values arbitrarily selected from the numerical value range can be used as upper and lower numerical values.
  • the Si particle bonded body of the present invention has Si particles and fibrous Si bonded to the Si particles, and the particle size of the Si particles is larger than the fiber diameter of the fibrous Si.
  • the form of the Si particle combination includes a combination of one Si particle and one fibrous Si bonded to the Si particle, a combination of one Si particle and two or more fibrous Si bonded to the Si particle, two Si particles, A combination of one fibrous Si bonded to both of them and a combination of a plurality of Si particles and a plurality of fibrous Si are included.
  • the fibrous Si is preferably bonded to a plurality of Si particles.
  • the Si particle bonded body is preferably a combination in which a plurality of Si particles and a plurality of fibrous Si are bonded.
  • the surface area of the Si particle bonded body is much larger than the surface area of the Si particle.
  • the particle diameter of the Si particles is preferably 10 nm or more and 1500 nm or less, more preferably 20 nm or more and 1200 nm or less, and further preferably 30 nm or more and 1000 nm or less.
  • the particle size of the Si particles here means the major axis of the observed Si particle image when the Si particle combination is observed with an electron microscope such as a scanning electron microscope or a transmission electron microscope.
  • the average particle diameter of the Si particles in the Si particle bonded body having a plurality of Si particles, or the aggregate or aggregate of the Si particle bonded bodies is preferably 10 nm to 300 nm, and preferably 20 nm to 200 nm. More preferably, it is 50 nm or more and 150 nm or less.
  • the average particle size of the means D 50 or the arithmetic mean value of the particle size of the Si particles.
  • D 50 is a particle size corresponding to an integrated value of volume distribution in the particle size distribution measurement by laser diffraction method of 50%. That is, the D 50, means the median size measured by volume.
  • the arithmetic average value can be obtained, for example, from the measurement result of the particle size of 200 Si particles.
  • the shape of the Si particles is not particularly limited, and examples thereof include a spherical shape, an elliptical spherical shape, and a droplet shape.
  • the fiber diameter of fibrous Si is preferably 4 nm or more and 25 nm or less, more preferably 5 nm or more and 20 nm or less, and further preferably 6 nm or more and 18 nm or less.
  • the fiber diameter of fibrous Si means the fiber diameter of the observed fibrous Si image when the Si particle combination is observed with an electron microscope such as a scanning electron microscope or a transmission electron microscope.
  • the fiber length of the fibrous Si is preferably 10 nm or more and 20 ⁇ m or less, more preferably 15 nm or more and 5 ⁇ m or less, and further preferably 20 nm or more and 2 ⁇ m or less.
  • the fiber length of fibrous Si means the fiber length of the observed fibrous Si image when the Si particle combination is observed with an electron microscope such as a scanning electron microscope or a transmission electron microscope.
  • the shape of the fibrous Si is not particularly limited as long as the fiber has a fiber length longer than the fiber diameter. Fibrous Si is bonded to Si particles at the end in the fiber length direction.
  • the particle diameter of Si particles is larger than the fiber diameter of fibrous Si.
  • the particle size of the Si particles is preferably 2 to 300 times the fiber diameter, more preferably 4 to 100 times, and even more preferably 6 to 20 times.
  • a plurality of Si particle aggregates may aggregate to form aggregates.
  • the size of the aggregate in the longitudinal direction is preferably 1 ⁇ m or more and 150 ⁇ m or less, more preferably 3 ⁇ m or more and 100 ⁇ m or less, and further preferably 5 ⁇ m or more and 50 ⁇ m or less.
  • the size of the aggregate in the longitudinal direction means the length in the longitudinal direction of the observed aggregate image when the aggregate is observed with an electron microscope such as a scanning electron microscope or a transmission electron microscope.
  • the Si particle bonded body includes voids due to its form.
  • a Si particle bonded body having a combination in which a plurality of Si particles and a plurality of fibrous Si are bonded includes a large number of voids.
  • the Si particle combination is used as a negative electrode active material for a non-aqueous electrolyte secondary battery, even if Si expands and contracts during charge and discharge, the voids serve as a buffering factor, so the overall size of the Si particle combination is Expect little change.
  • FIG. 1 shows a schematic diagram of a bonded Si particle of the present invention.
  • each fibrous Si 20 is bonded to a plurality of Si particles 10 to form one Si particle bonded body 40. Further, the Si particle bonded body 40 shown in FIG. In FIG. 1, a plurality of fibrous Si 20 bonded to a plurality of Si particles 10 forms a network structure.
  • Si contained in the Si particle bonded body has Si crystal.
  • both the Si particles and the fibrous Si preferably contain Si crystals.
  • the coated Si particle bonded body of the present invention is characterized by having the above Si particle bonded body and a carbon-containing film disposed on the surface of the Si particle bonded body.
  • the Si particle combination is as described above.
  • the surface of the Si particle bonded body refers to the surface of the Si particles, the surface of the fibrous Si, and the surface of the bonded portion between the Si particles and the fibrous Si.
  • the carbon-containing coating is preferably disposed on the entire surface of the Si particle bonded body.
  • the thickness of the carbon-containing film is not particularly limited.
  • the thickness of the carbon-containing coating is preferably 1 nm or more and 20 nm or less, more preferably 1 nm or more and 10 nm or less, and further preferably 1 nm or more and 5 nm or less.
  • the thickness of the carbon-containing coating here refers to the thickness when observed with an electron microscope such as a scanning electron microscope or a transmission electron microscope.
  • the carbon-containing film has at least carbon.
  • the carbon-containing film may further contain hydrogen and oxygen. Since Si has low conductivity, it is presumed that conductivity can be improved by having a carbon-containing film.
  • the coated Si particle combination of the present invention is used as a negative electrode active material of a battery, it is expected that battery characteristics can be improved.
  • the carbon-containing film preferably contains amorphous carbon.
  • the coated Si particle combination of the present invention having a carbon-containing coating containing amorphous carbon is used as the negative electrode active material of a battery, the carbon-containing coating is bonded to Si particles even if Si expands or contracts during charge and discharge. Expected to be difficult to peel off from the surface of the body and expected to improve battery characteristics.
  • the carbon-containing film is preferably a film containing C, H, and O elements.
  • XPS X-ray photoelectron spectroscopy
  • the peak tops found in the range of 1420 cm ⁇ 1 to 1480 cm ⁇ 1 are derived from CH 2 or CH 3 .
  • the carbon-containing film has an ester skeleton when the carbon-containing film has the above peak in the high resolution spectrum of the C1s orbit by XPS.
  • Films containing C, H, and O elements should detect terpene fragments in pyrolysis gas chromatograph mass spectrometry (hereinafter referred to as pyrolysis GC-MS as appropriate) at pyrolysis temperatures up to 270 ° C. Is preferred.
  • pyrolysis GC-MS pyrolysis gas chromatograph mass spectrometry
  • the Si particle bonded body of the present invention since the film is formed on the surface of the Si particle bonded body, the Si particle bonded body is hardly oxidized even in an oxygen-containing atmosphere.
  • the oxygen content of the coated Si particle conjugate of the present invention is preferably 10% or less, more preferably 8% or less, and even more preferably 6% or less.
  • the method for producing a Si particle bonded body of the present invention includes a step of introducing raw material Si powder into a plasma having a plasma output of 5 kW or more and less than 15 kW by an introduction flow, and a flow after the introduction flow has passed through the plasma. And a cooling step of cooling with a cooling gas flow facing the passing flow.
  • the method for producing a coated Si particle assembly of the present invention includes a step of introducing raw material Si powder into a plasma having a plasma output of 5 kW or more and less than 15 kW by an introduction flow, and after the introduction flow has passed through the plasma.
  • the D 50 of the raw material Si powder is not particularly limited, but is preferably 1 ⁇ m to 100 ⁇ m, more preferably 1 ⁇ m to 40 ⁇ m, and even more preferably 2 ⁇ m to 10 ⁇ m.
  • the raw material Si powder of D 50 is too small, the less likely to move the raw material Si powder due to static electricity or the like, the raw material Si powder of D 50 is too large, to have hardly a possibility that uniformly moves the raw material Si powder, In addition, it may be difficult to vaporize or make the entire amount of the raw material Si powder introduced into the liquid state in the plasma.
  • D 50 can be measured by particle size distribution measurement method.
  • D 50 is a particle diameter corresponding to an integrated value of volume distribution in particle size distribution measurement by laser diffraction method corresponding to 50%. That is, the D 50, means the median size measured by volume.
  • the manufacturing method of the Si particle combination and the coated Si particle combination of the present invention is carried out using a plasma generator.
  • the plasma may be generated by arc discharge, multiphase arc discharge, high frequency electromagnetic induction, microwave heating discharge, or the like.
  • the frequency may be, for example, in the range of 0.5 MHz to 400 MHz, preferably in the range of 1 MHz to 80 MHz.
  • the plasma output is 5 kW or more and less than 15 kW, and more preferably 5 kW or more and 10 kW or less. If the plasma output is 5 kW or more and less than 15 kW, SiC is hardly generated when a gas containing a carbon source gas is used as the cooling gas.
  • the pressure in the plasma generator may be set as appropriate, for example, the range of 10 kPa to atmospheric pressure can be exemplified.
  • the average particle diameter of the Si particles can be changed by changing the plasma output or the pressure in the plasma generator.
  • the average particle size of the Si particles can be reduced by bringing the pressure in the plasma generator close to atmospheric pressure.
  • the introduction flow is generated by the flow of gas toward the plasma.
  • a gas that can be used under the plasma is preferably used as the main flow.
  • the gas constituting the introduction flow that is, the introduction gas, a rare gas such as helium or argon or hydrogen is preferable.
  • an introduction gas flow rate 20 L / min. ⁇ 120 L / min. Can be illustrated.
  • the introduced gas it is introduced into the coil separately from the carrier gas carrying the raw Si powder and the carrier gas. It is preferable to employ an inner gas to be used and a process gas for bringing the plasma generation site into an inert atmosphere.
  • the carrier gas flow rate is 1 L / min. ⁇ 10L / min. Can be illustrated.
  • the flow rate of the carrier gas is 1 L / min. ⁇ 5L / min. Is preferred.
  • the flow rate of the inner gas is 1 L / min. ⁇ 10L / min. Can be illustrated.
  • the flow rate of the inner gas is 1 L / min. ⁇ 5L / min. Is preferred.
  • the flow rate of the process gas is 15 L / min. To 100 L / min. Can be illustrated.
  • As the flow rate of the process gas 30 L / min. To 100 L / min. Is preferred.
  • the introduction flow rate is the sum of the carrier gas flow rate, the inner gas flow rate, and the process gas flow rate.
  • the temperature in the plasma becomes higher than when only argon is used as the process gas.
  • the temperature in the plasma when only argon is used as the process gas is about 10,000 ° C.
  • a mixed gas of argon and helium when using as a process gas, the temperature in the plasma is about 15,000 ° C.
  • the feed rate of the raw material Si powder is 50 mg / min. -1000 mg / min. Is preferable, and 50 mg / min. ⁇ 500 mg / min. Is more preferable. If the supply speed of the raw material Si powder becomes too fast, a lot of Si powder is vaporized. There are cases where the thermal energy of the plasma is deprived by the vaporization of many Si powders and the temperature in the plasma is too low.
  • the flow after the introduction flow passes through the plasma is cooled by the opposing cooling gas flow. Since the inside of the plasma is in a high temperature state and the ambient temperature outside the plasma is room temperature, the passing flow is rapidly cooled simply by going out of the plasma from the plasma. Further, the ambient temperature outside the plasma can be further lowered by cooling the entire plasma generator with cooling water or the like.
  • the cooling gas flow facing the through flow toward the through flow the cooling gas flow and the through flow are in good contact with each other, and the through flow is uniformly cooled. Further, the cooling gas flow facing the passing flow is injected toward the passing flow, so that Si in the passing flow rides on the cooling gas flow and convects.
  • the temperature in the plasma is about 8,000 ° C. to 20,000 ° C.
  • Si nuclei are generated at about 2,000 ° C. to 2,300 ° C., and it is considered that many particles are generated around the nuclei. It is considered that the particles grow as a result of the other particles agglomerating with the generated particles as the through flow is cooled.
  • Si in the passing flow rides on the cooling gas flow and convects, Si having different degrees of cooling, that is, Si having different particle diameters, come into contact with each other during convection.
  • the Si particle bonded body of the present invention is presumed to be formed by bonding Si having different particle diameters during convection. Although the reason for the fibrous Si in the Si particle bonded body of the present invention is unknown, it is considered that Si particles having small particle diameters are connected to form fibrous Si.
  • the cooling gas is preferably a rare gas such as helium or argon.
  • the temperature of the cooling gas may be room temperature or lower than room temperature.
  • the flow rate of the cooling gas may be a flow rate smaller than the introduction flow, for example, 0.1 L / min. ⁇ 30 L / min. This can be illustrated as an example.
  • the flow rate of the cooling gas is 0.2 L / min. 25 L / min. Or less, preferably 0.3 L / min. 20 L / min. The following is more preferable.
  • cooling is performed with a cooling gas flow containing a carbon source gas, and Si in the passing flow is brought into contact with the carbon source gas to form a carbon-containing coating on Si.
  • the cooling gas flow containing the carbon source gas is injected toward the passing flow, it is preferable that the carbon source gas is not mixed into the plasma. If the carbon source gas is mixed in the plasma, Si and C may react to generate SiC as an impurity. When SiC is generated, Si is consumed, and the amount of Si particles may be reduced.
  • the carbon source gas is injected toward the passing flow so that the reaction field becomes an atmosphere of 1700 K (about 1427 ° C.) or less.
  • the temperature atmosphere of the reaction field can be adjusted by adjusting the plasma output and the injection position of the carbon source gas.
  • Examples of the carbon source gas include alkanes such as methane, ethane, propane, butane, pentane, hexane, heptane, and octane, alkynes such as acetylene, methylacetylene, butyne, pentyne, hexyne, heptine, and octyne, ethylene, Alkenes such as propylene, butene, pentene, hexene, heptene, octene, ethers such as dimethyl ether, ethyl methyl ether, diethyl ether, ethyl propyl ether, dipropyl ether, propyl butyl ether, dibutyl ether, ethylene glycol, propylene glycol, glycerin Glycols such as methyl formate, ethyl formate, ethyl acetate, methyl acetate,
  • a carbon source gas When producing a coated Si particle combination, only a carbon source gas may be used as a cooling gas, or a carbon source gas and a rare gas may be used in combination.
  • the flow rate of the carbon source gas is, for example, 0.1 L / min. ⁇ 10L / min. Within the range of 0.1 L / min. 5 L / min. Or less, preferably 0.1 L / min. 3 L / min. The following is more preferable.
  • the coating structure can be adjusted by adjusting the number of moles of carbon source gas supplied per unit time relative to the number of moles of raw material Si powder supplied per unit time. .
  • the production of SiC can be suppressed by setting C / Si, which is the ratio of the number of moles of carbon source gas supplied per unit time to the number of moles of raw material Si powder supplied per unit time, to 1.5 or less. . If C / Si is 0.5 or more, a carbon-containing coating can be easily produced on the surface of the Si particle combination. When C / Si is too large, SiC is likely to be generated, and when C / Si is too small, it becomes difficult to form a carbon-containing coating on the surface of the Si particle combination.
  • the carbon particle-containing Si particle bonded body formed in the cooling step is maintained in an oxygen-containing atmosphere, and oxygen is introduced into the carbon-containing coated film.
  • the cooling step when the temperature of the reaction field is low or the reaction time is short, all of the H contained in the carbon source gas is not dissociated and CH in the radical state exists on the surface of the Si particle bonded body. Is guessed. Therefore, when the carbon-containing film having CH in the radical state is placed in an oxygen-containing atmosphere after the cooling step, oxygen is bonded to the CH in the radical state, and oxygen is easily introduced into the carbon-containing film. Further, it is considered that the surface of the Si particle bonded body is stabilized by contact of oxygen and radical state CH. That is, it can be said that the oxygen introduction step is a stabilization step of the coated Si particle combination.
  • a raw material Si powder is introduced into a plasma by an introduction flow, and a passing flow after the introduction flow passes through the plasma is opposed to the passing flow. Cooling with a cooling gas stream containing a carbon source gas, and contacting Si in the passing stream with the carbon source gas to form a carbon-containing film on the Si, wherein the cooling gas stream is carbon
  • the supply position of the carbon source gas includes the source gas and the rare gas, and is characterized in that the supply position of the carbon source gas is downstream with respect to the passage direction of the passing flow.
  • the opening for supplying the rare gas and the opening for supplying the carbon source gas are separated, and the position of the opening for supplying the carbon source gas is changed to the position of the rare gas. What is necessary is just to set to the position which is downstream with respect to the passage direction of a passage flow rather than the position of the opening part to supply.
  • the distance between the opening of the carbon source gas supply pipe and the opening in the plasma generator is 50 mm or more than the distance between the opening of the rare gas supply pipe and the opening in the plasma generator. It is preferable to enlarge it.
  • the plasma output, the feed rate of the raw material Si powder, the flow rate of the carbon source gas, and the supply position of the carbon source gas are appropriately adjusted.
  • the supply rate of the raw material Si powder, the flow rate of the carbon source gas, and the supply position of the carbon source gas may be adjusted in accordance with the magnitude of the plasma output. If the plasma output is increased, the feed rate of the raw material Si powder can be increased without greatly reducing the temperature in the plasma.
  • the supply position of the carbon source gas may be further downstream than the supply position of the rare gas with respect to the passing direction of the passing flow. By making the supply position of the carbon source gas further downstream with respect to the passing direction of the passing flow, the generation of SiC as an impurity can be suppressed even if the supply speed of the raw material Si powder is increased.
  • the plasma output is preferably 3 kW to 300 kW, more preferably 5 kW to 100 kW, and even more preferably 5 kW to 20 kW.
  • the supply rate of the raw material Si powder per plasma output is 0.01 g / min. / KW to 1 g / min. / KW is preferred, and 0.01 g / min. / KW to 0.5 g / min. / KW is more preferable, 0.01 g / min. / KW to 0.1 g / min. / KW is more preferable.
  • the Si particle bonded body or coated Si particle bonded body of the present invention can be used as a negative electrode active material for a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery.
  • the negative electrode active material containing the Si particle combination or the coated Si particle combination of the present invention is referred to as the negative electrode active material of the present invention.
  • the following invention can be grasped as the second negative electrode active material of the present invention derived from the negative electrode active material of the present invention.
  • the second negative electrode active material of the present invention has Si particles and a carbon-containing film that is disposed on the surface of the Si particles and contains C, H, and O.
  • the carbon-containing film has a pyrolysis gas chromatograph mass. The analysis is characterized in that fragments of terpenes are detected.
  • the Si particles may be of any shape as long as they are manufactured using the plasma generator.
  • the negative electrode active material of the present invention For other matters related to the second negative electrode active material of the present invention, the description of the negative electrode active material of the present invention is incorporated.
  • the negative electrode including the negative electrode active material or the second negative electrode active material of the present invention is referred to as the negative electrode of the present invention
  • the nonaqueous electrolyte secondary battery including the negative electrode of the present invention is referred to as the nonaqueous electrolyte secondary battery of the present invention.
  • the non-aqueous electrolyte secondary battery of the present invention will be described using a lithium ion secondary battery as an example.
  • the negative electrode in the lithium ion secondary battery of the present invention has a current collector and a negative electrode active material layer bound to the surface of the current collector.
  • the negative electrode active material of the present invention or the second negative electrode active material of the present invention is used as the negative electrode active material.
  • the negative electrode active material layer in the lithium ion secondary battery of the present invention includes other known negative electrode active materials, binders, conductive assistants, Other additives may be included.
  • Examples of other known negative electrode active materials include carbon-based materials capable of inserting and extracting lithium, elements capable of being alloyed with lithium, compounds having elements capable of being alloyed with lithium, and polymer materials. it can. As other known negative electrode active materials, carbon-based materials are preferable.
  • the carbon-based material examples include non-graphitizable carbon, graphite, coke, graphite, glassy carbon, organic polymer compound fired body, carbon fiber, activated carbon, or carbon black.
  • the organic polymer compound fired body refers to a material obtained by firing and carbonizing a polymer material such as phenols and furans at an appropriate temperature.
  • elements that can be alloyed with lithium include Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Ti, Ag, Zn, Cd, Al, Ga, In, Si. , Ge, Sn, Pb, Sb, and Bi.
  • compounds having elements that can be alloyed with lithium include ZnLiAl, AlSb, SiB 4 , SiB 6 , Mg 2 Si, Mg 2 Sn, Ni 2 Si, TiSi 2 , MoSi 2 , CoSi 2 , NiSi 2 , CaSi 2, CrSi 2, Cu 5 Si, FeSi 2, MnSi 2, NbSi 2, TaSi 2, VSi 2, WSi 2, ZnSi 2, SiC, Si 3 N 4, Si 2 N 2 O, SiO v (0 ⁇ v ⁇ 2), SnO w (0 ⁇ w ⁇ 2), SnSiO 3 , LiSiO 2 or LiSnO.
  • polymer material examples include polyacetylene and polypyrrole.
  • the amount of the negative electrode active material when the total amount of the negative electrode active material layer is 100% by mass is preferably in the range of 60% by mass to 99% by mass, more preferably in the range of 65% by mass to 98% by mass, A range of 70% by mass to 97% by mass is particularly preferable.
  • the binder serves to bind the negative electrode active material and the conductive auxiliary agent to the surface of the current collector.
  • Binders include fluorine-containing resins such as polyvinylidene fluoride, polytetrafluoroethylene, and fluororubber, thermoplastic resins such as polypropylene and polyethylene, imide resins such as polyimide and polyamideimide, alkoxysilyl group-containing resins, and styrene butadiene. Rubber can be exemplified. Moreover, you may employ
  • hydrophilic group of the polymer having a hydrophilic group examples include a carboxyl group, a sulfo group, a silanol group, an amino group, a hydroxyl group, and a phosphate group.
  • Specific examples of the polymer having a hydrophilic group include a polymer containing a carboxyl group in a molecule such as polyacrylic acid, carboxymethylcellulose, and polymethacrylic acid, or a polymer containing a sulfo group such as poly (p-styrenesulfonic acid). It is done.
  • a crosslinked polymer obtained by crosslinking a carboxyl group-containing polymer such as polyacrylic acid or polymethacrylic acid with a polyamine such as diamine disclosed in International Publication No. 2016/063882 may be used as a binder.
  • Diamines used in the crosslinked polymer include alkylene diamines such as ethylene diamine, propylene diamine, and hexamethylene diamine, 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, isophorone diamine, bis (4-aminocyclohexyl) methane, and the like.
  • the blending amount of the binder is not particularly limited. However, when the blending amount of the binder in the negative electrode active material layer is given, it is preferably in the range of 0.5% by mass to 10% by mass, and 1% by mass to 7% by mass. Is more preferable, and the range of 2% by mass to 5% by mass is particularly preferable. If the blending amount of the binder is too small, the moldability of the negative electrode active material layer may be lowered. Moreover, when there are too many compounding quantities of a binder, since the quantity of the negative electrode active material in a negative electrode active material layer reduces relatively, it is unpreferable.
  • the conductive auxiliary agent may be any chemically inert electronic high conductor, such as carbon black, graphite, vapor grown carbon fiber (Vapor Grown Carbon Fiber), and various metal particles.
  • carbon black examples include acetylene black, ketjen black (registered trademark), furnace black, and channel black.
  • These conductive assistants can be added to the negative electrode active material layer alone or in combination of two or more.
  • the shape of the conductive auxiliary agent is not particularly limited, but it is preferable that the average particle size of the conductive auxiliary agent is small in view of its role.
  • a preferable average particle size of the conductive assistant is 10 ⁇ m or less, and a more preferable average particle size is in the range of 0.01 ⁇ m to 1 ⁇ m.
  • the blending amount of the conductive assistant is not particularly limited, but if the blending amount of the conductive assistant in the negative electrode active material layer is given, it is preferably in the range of 0.5% by mass to 10% by mass, and 1% by mass to 7% by mass. Is preferably within the range of 2% by mass to 5% by mass.
  • additives can be used as additives such as a dispersant other than the conductive auxiliary agent and the binder.
  • a current collector refers to a chemically inert electronic high conductor that keeps a current flowing through an electrode during discharge or charging of a lithium ion secondary battery.
  • the current collector at least one selected from silver, copper, gold, aluminum, tungsten, cobalt, zinc, nickel, iron, platinum, tin, indium, titanium, ruthenium, tantalum, chromium, molybdenum, and stainless steel, etc. Metal materials can be exemplified.
  • the current collector may be covered with a known protective layer. What collected the surface of the electrical power collector by the well-known method may be used as an electrical power collector.
  • the current collector can take the form of a foil, a sheet, a film, a linear shape, a rod shape, a mesh, or the like. Therefore, for example, a metal foil such as a copper foil, a nickel foil, an aluminum foil, and a stainless steel foil can be suitably used as the current collector.
  • a metal foil such as a copper foil, a nickel foil, an aluminum foil, and a stainless steel foil can be suitably used as the current collector.
  • the thickness is preferably in the range of 1 ⁇ m to 100 ⁇ m.
  • a negative electrode active material may be applied to the surface of the current collector.
  • an active material, a solvent, and if necessary, a binder and a conductive additive are mixed to form a slurry, and the slurry is applied to the surface of the current collector and then dried.
  • the solvent include N-methyl-2-pyrrolidone, methanol, methyl isobutyl ketone, and water.
  • the dried product may be compressed.
  • Examples of one aspect of the lithium ion secondary battery of the present invention include those equipped with the negative electrode, positive electrode, electrolytic solution, and separator of the present invention.
  • the positive electrode has a current collector and a positive electrode active material layer bound on the current collector.
  • the positive electrode active material layer includes a positive electrode active material and a binder, and may further include a conductive additive and other additives.
  • a positive electrode active material, a conductive support agent, and a binder are not particularly limited.
  • the positive electrode active material a material capable of occluding and releasing charge carriers such as Li may be used.
  • a solid solution composed of a spinel such as LiMn 2 O 4 and Li 2 Mn 2 O 4 and a mixture of a spinel and a layered compound, LiMPO 4 , LiMVO 4, or Li 2 MSiO 4 (M in the formula) are selected from at least one of Co, Ni, Mn, and Fe).
  • tavorite compound (the M a transition metal) LiMPO 4 F, such as LiFePO 4 F represented by, Limbo 3 such LiFeBO 3 (M is a transition metal) include borate-based compound represented by be able to.
  • any metal oxide used as the positive electrode active material may have the above composition formula as a basic composition, and a metal element contained in the basic composition may be substituted with another metal element.
  • a positive electrode active material that does not contain lithium ions contributing to charge / discharge, for example, sulfur alone (S), a compound in which sulfur and carbon are combined, a metal sulfide such as TiS 2 , V 2 O, etc. 5 , oxides such as MnO 2 , polyaniline and anthraquinone, compounds containing these aromatics in the chemical structure, conjugated materials such as conjugated diacetic acid organic materials, and other known materials can also be used.
  • a compound having a stable radical such as nitroxide, nitronyl nitroxide, galvinoxyl, phenoxyl, etc. may be adopted as the positive electrode active material.
  • a positive electrode active material that does not contain lithium it is necessary to add ions to the positive electrode and / or the negative electrode in advance by a known method.
  • a metal or a compound containing the ion may be used.
  • the current collector used for the positive electrode is not limited as long as it is generally used for the positive electrode of a lithium ion secondary battery, such as aluminum, nickel, and stainless steel. .
  • the electrolytic solution contains a non-aqueous solvent and an electrolyte dissolved in the non-aqueous solvent.
  • cyclic esters examples include ethylene carbonate, propylene carbonate, butylene carbonate, gamma butyrolactone, vinylene carbonate, 2-methyl-gamma butyrolactone, acetyl-gamma butyrolactone, and gamma valerolactone.
  • chain esters include dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dipropyl carbonate, ethyl methyl carbonate, propionic acid alkyl ester, malonic acid dialkyl ester, and acetic acid alkyl ester.
  • ethers examples include tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, and 1,2-dibutoxyethane.
  • non-aqueous solvent a compound in which a part or all of hydrogen in the chemical structure of the above specific solvent is substituted with fluorine may be employed.
  • Examples of the electrolyte include lithium salts such as LiClO 4 , LiAsF 6 , LiPF 6 , LiBF 4 , LiCF 3 SO 3 , and LiN (CF 3 SO 2 ) 2 .
  • a lithium salt such as LiClO 4 , LiPF 6 , LiBF 4 , LiCF 3 SO 3 in a nonaqueous solvent such as ethylene carbonate, dimethyl carbonate, propylene carbonate, and diethyl carbonate.
  • a solution dissolved at a concentration of about / L can be exemplified.
  • the separator separates the positive electrode and the negative electrode and allows lithium ions to pass while preventing a short circuit due to contact between the two electrodes.
  • natural resins such as polytetrafluoroethylene, polypropylene, polyethylene, polyimide, polyamide, polyaramid (Aromatic polymer), polyester, polyacrylonitrile, etc., polysaccharides such as cellulose, amylose, fibroin, keratin, lignin, suberin, etc. Examples thereof include porous bodies, nonwoven fabrics, and woven fabrics using one or more electrically insulating materials such as polymers and ceramics.
  • the separator may have a multilayer structure.
  • the method for producing a lithium ion secondary battery of the present invention includes a step of disposing the negative electrode of the present invention. Specifically, it is as follows.
  • a separator is sandwiched between the positive electrode and the negative electrode as necessary to form an electrode body.
  • the electrode body may be any of a stacked type in which a positive electrode, a separator and a negative electrode are stacked, or a wound type in which a positive electrode, a separator and a negative electrode are sandwiched.
  • an electrolytic solution is added to the electrode body to form a lithium ion secondary battery. It is good to do.
  • the lithium ion secondary battery of this invention should just be charged / discharged in the voltage range suitable for the kind of active material contained in an electrode.
  • the shape of the lithium ion secondary battery of the present invention is not particularly limited, and various shapes such as a cylindrical shape, a square shape, a coin shape, and a laminate shape can be adopted.
  • the lithium ion secondary battery of the present invention may be mounted on a vehicle.
  • the vehicle may be a vehicle that uses electric energy from the secondary battery for all or part of its power source, and may be, for example, an electric vehicle, a hybrid vehicle, or the like.
  • a lithium ion secondary battery is mounted on a vehicle, a plurality of lithium ion secondary batteries may be connected in series to form an assembled battery.
  • devices equipped with lithium ion secondary batteries include various home appliances driven by batteries such as personal computers and portable communication devices, office devices, and industrial devices in addition to vehicles.
  • the lithium ion secondary battery of the present invention includes wind power generation, solar power generation, hydroelectric power generation and other power system power storage devices and power smoothing devices, power supplies for ships and / or auxiliary power supply sources, aircraft, Power supply for spacecraft and / or auxiliary equipment, auxiliary power supply for vehicles that do not use electricity as a power source, power supply for mobile home robots, power supply for system backup, power supply for uninterruptible power supply, You may use for the electrical storage apparatus which stores temporarily the electric power required for charge in the charging station for electric vehicles.
  • Example 1 The powder of Example 1 was manufactured using the plasma generator shown in FIG.
  • the raw material powder is supplied from the powder supplier 1, and the raw material powder is introduced into the plasma generator 11 through the carrier gas path 6.
  • the carrier gas is introduced into the plasma generator 11 through the carrier gas path 6, the process gas is introduced into the plasma generator 11 through the process gas path 7, and the inner gas is introduced into the plasma generator 11 through the inner gas path 8.
  • the Power is supplied by the power supply device 2, and plasma is generated in the plasma generator 11.
  • the cooling gas carried through the cooling gas path 9 is injected in a direction opposite to the passing flow after passing through the plasma.
  • the distance between the opening of the cooling gas supply pipe 91 and the opening of the plasma generator 11 was 200 mm.
  • Each gas is exhausted out of the apparatus through an exhaust section 3 provided with a filter 4.
  • the product falls by its own weight and is stored in the lower part of the internal chamber 5.
  • the white arrow represents the cooling water.
  • Si powder having a D 50 of 3 ⁇ m (manufactured by Kojundo Chemical Laboratory Co., Ltd., product number SIE23PB) was prepared.
  • the raw material Si powder was placed in a powder feeder.
  • argon gas as a process gas was added at 60 L / min. At 5 L / min. As an inner gas.
  • Methane gas as a cooling gas at 0.32 L / min. Supplied with.
  • the flow rate of methane gas was measured using a float type flow meter attached to the supply pipe. At this time, power was supplied from the power supply device, and a magnetic field with a frequency of 4 MHz was applied to the coil to generate plasma with an output of 10 kW.
  • the pressure in the plasma generator was atmospheric pressure.
  • the powder feeder is operated, and the raw material Si powder is 400 mg / min. Was introduced into the plasma together with the carrier gas at a rate of The powder released along with the flow after passing through the plasma was collected and held in an oxygen atmosphere for 1 hour. The obtained powder was used as the powder of Example 1.
  • C / Si which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, is 1.0.
  • Example 1 The powder cross section of Example 1 was observed by SEM. Cross-sectional SEM observation results are shown in FIG. 3, FIG. 4, and FIG. FIG. 4 shows the result of 10 ⁇ magnification of FIG. 3, and FIG. 5 shows the result of 100 ⁇ magnification of FIG. In FIG. 3, FIG. 4, and FIG. 5, a coated Si particle combination having the form of an aggregate was observed. In FIG. 4, it was clearly observed that the Si particles were dispersed in the aggregate.
  • the size in the longitudinal direction of the aggregate of the powder Si particle aggregate of Example 1 was measured. As a result of measuring 100 aggregates of the Si particle aggregate, the size in the longitudinal direction of the entire Si particle aggregate of the powder of Example 1 was 20 ⁇ m or more and 150 ⁇ m or less.
  • Example 1 was observed with a TEM.
  • the TEM observation result of the powder of Example 1 is shown in FIG.
  • Si particles 10 and fibrous Si20 were observed.
  • a plurality of fibrous Si was bonded to the Si particles 10 and that the fibrous Si 20 was bonded to a plurality of Si particles.
  • the fiber diameter of fibrous Si is about 10 nm, and the particle diameter of Si particle is about 100 nm.
  • the particle size of the Si particles of the powder of Example 1 was measured. 200 major axes of each Si particle of the powder of Example 1 were measured. The particle size of the Si particles in the powder of Example 1 was not less than 30 nm and less than 1000 nm. A particle size distribution diagram of the Si particles of the powder of Example 1 was created using the measured numerical values. A particle size distribution diagram is shown in FIG. The D 50 of the Si particles of the powder of Example 1 was 70 nm.
  • the fiber diameter of fibrous Si was measured. 100 fiber diameters of each fibrous Si of the powder of Example 1 were measured. The fiber diameter of fibrous Si was 8 nm or more and 15 nm or less. The arithmetic average value of the fiber diameter of fibrous Si of the powder of Example 1 calculated from the measured value was 10 nm.
  • the fiber length of fibrous Si was measured. 100 fiber lengths of each fibrous Si of the powder of Example 1 were measured. The fiber length of the fibrous Si was 30 nm or more and 1 ⁇ m or less.
  • the surface of the powder Si particle combination of Example 1 was observed with a transmission electron microscope-energy dispersive X-ray spectroscopy (hereinafter referred to as TEM-EDS).
  • TEM-EDS transmission electron microscope-energy dispersive X-ray spectroscopy
  • Si was measured in the Si particles 10
  • Si was measured in the central portion of the bonding portion 50. That is, it was observed that the fibrous Si and the Si particles 10 were integrated in the joint portion 50.
  • the coating was observed on both the Si particles, the fibrous Si, and the bonding portion, it is presumed that the coating has an effect of reinforcing the structure of the Si particle bonded body.
  • C and O were measured on the film 60.
  • the following can be considered as a mechanism in which C and O are contained in the film 60.
  • the powder after passing through the plasma was held for 1 hour in an oxygen atmosphere. It is presumed that CH in a radical state exists on the surface of the powder after passing through the plasma. Therefore, when a film having CH in a radical state is placed in an oxygen-containing atmosphere, oxygen is bonded to CH in the radical state, and oxygen is easily introduced into the film. As a result, it is presumed that C and O are contained in the coating 60 on the surface of the powder.
  • FIG. 11 A schematic diagram of the TEM observation result of the powder of Example 1 is shown in FIG.
  • TEM-EELS transmission electron microscope-electron energy loss spectroscopy
  • Example 2 Argon gas was used as a cooling gas at 20 L / min.
  • the powder of Example 2 was produced in the same manner as the powder of Example 1 except that methane gas was not supplied.
  • C / Si which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 0.
  • Example 3 As a cooling gas, methane gas is 0.16 L / min. Thus, the powder of Example 3 was produced in the same manner as the powder of Example 1 except that it was supplied.
  • C / Si which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 0.5.
  • Example 4 As a cooling gas, methane gas is 0.48 L / min. Thus, the powder of Example 4 was produced in the same manner as the powder of Example 1 except that it was supplied.
  • C / Si which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 1.5.
  • Example 5 Methane gas is used as the cooling gas at 0.576 L / min.
  • a powder of Example 5 was produced in the same manner as the powder of Example 1 except that the powder was supplied in Step 1.
  • C / Si which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 1.8.
  • Example 6 As a cooling gas, methane gas is 0.64 L / min.
  • a powder of Example 6 was produced in the same manner as the powder of Example 1 except that the powder was supplied in Step 6.
  • C / Si which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 2.0.
  • Example 7 The distance between the opening of the cooling gas supply pipe and the opening in the plasma generator is 150 mm, and methane gas is used as the cooling gas at 0.56 L / min. At a raw material Si powder of 700 mg / min. The powder of Example 7 was produced in the same manner as the powder of Example 1, except that the speed was changed. C / Si, which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 1.
  • Comparative Example 1 A powder of Comparative Example 1 was obtained in the same manner as the powder of Example 1 except that the plasma output was 15 kW.
  • Comparative Example 2 A powder of Comparative Example 2 was obtained in the same manner as the powder of Example 1 except that the plasma output was 20 kW.
  • FIG. 14 shows the Raman spectra of the powder coating of Example 1, the powder coating of Comparative Example 1, and the powder coating of Comparative Example 2.
  • the horizontal axis represents the wave number (cm ⁇ 1 )
  • the vertical axis represents the scattering intensity.
  • the measurement conditions were a wavelength of 532 nm, a measurement range of 450 cm ⁇ 1 -1700 cm ⁇ 1 , a measurement time of 30 seconds, and an integration count of 50 times.
  • the G band is a peak due to graphite
  • the D band is a peak due to carbon atoms having dangling bonds such as amorphous carbon. From this, it was confirmed that the powder coating of Example 1, the powder coating of Comparative Example 1, and the powder coating of Comparative Example 2 contained graphite and amorphous carbon.
  • the Raman spectra of the powder of Example 1 further, 1230 cm -1 ⁇ 1270 cm -1, a peak was observed in the range of 1420cm -1 ⁇ 1480cm -1. These peaks were not observed in the Raman spectra of the powder of Comparative Example 1 and the powder of Comparative Example 2.
  • the peaks in the range of 1230 cm ⁇ 1 to 1270 cm ⁇ 1 are peaks derived from Si—CH 2 and / or Si—CH 3, and the peaks in the range of 1420 cm ⁇ 1 to 1480 cm ⁇ 1 are CH 2 and / or CH 3. It is a peak derived from. From this, unlike the powder coating of Comparative Example 1 and the powder coating of Comparative Example 2, the element H remains in the powder coating of Example 1, and the structure is derived from CH 2 and / or CH 3. It was confirmed that
  • the following may be considered as a mechanism in which the coating in the powder of Example 1 has a structure derived from CH 2 and / or CH 3 .
  • the powder of Example 1 was produced with a plasma output of 10 kW, and was cooled by a cooling gas containing a carbon source gas during production. In the hydrocarbon gas contained in the carbon source gas, dissociation of H proceeds by thermal plasma.
  • the dissociation energy of C—H bond is about 480 kJ / mol. For example, in order to dissociate all H from CH 4 , energy of about 1600 kJ / mol is required.
  • the plasma output at the time of production was 15 kW and 20 kW, which was higher energy than at the time of production of the powder of Example 1, so CH 4 was decomposed to C alone, and the coating film was It is presumed that there was no structure derived from CH 2 and / or CH 3 .
  • FIG. 15 shows the XPS measurement results of the coating films of the powder of Example 1, the powder of Example 3, and the powder of Example 4.
  • the horizontal axis represents the binding energy (eV)
  • the vertical axis represents the strength (au).
  • FIG. 15 shows a side-by-side description of the high-resolution spectrum of the C1s orbit of each sample. As shown in FIG. 15, peaks were observed at 287 eV to 290 eV in the high resolution spectrum of the C1s orbit of each sample.
  • the peak observed at 287 eV to 290 eV is presumed to be a peak derived from R—COO—R ′. Therefore, it is considered that the structure of C and O included in the coating includes O ⁇ C—O. Therefore, it is estimated that the film has an ester skeleton.
  • the peak seen at 287 eV to 290 eV increases toward the high energy side as the C / Si ratio increases. A shift was observed.
  • the coating film of the powder of Example 4, the coating film of the powder of Reference Example 1 shown below, and the coating film of the powder of Reference Example 2 were measured by pyrolysis gas chromatography.
  • the heating conditions in the measurement were 25 ° C. to 270 ° C., and the heating rate was 10 ° C./min. It was.
  • Substances adsorbed by pyrolysis gas chromatography in the temperature range of 25 ° C. to 270 ° C. were analyzed.
  • FIG. 16 shows the measurement results of the powder coating of Example 4, the powder coating of Reference Example 1, and the powder coating of Reference Example 2.
  • the powder of Reference Example 1 and the powder of Reference Example 2 are the following Si-based powders with a carbon coating.
  • the silicon material coated with carbon was used as the powder of Reference Example 1.
  • the furnace core tube of the reactor was disposed in the horizontal direction, and the rotational speed of the core tube was 1 rpm.
  • a baffle plate is disposed on the inner peripheral wall of the core tube, and the contents accumulated on the baffle plate with the rotation of the core tube are configured to fall from the baffle plate at a predetermined height. The contents are stirred during the reaction.
  • the average thickness of the powder coating of Reference Example 1 was 15 nm.
  • Si powder coated with carbon was produced by performing thermal CVD with a rotary kiln using Si powder having a D 50 of 3 ⁇ m manufactured by Kojundo Chemical Laboratory Co., Ltd. in the same manner as the powder of Reference Example 1 above.
  • the Si powder coated with carbon was used as the powder of Reference Example 2.
  • the average thickness of the powder coating of Reference Example 2 was 15 nm.
  • the powder coating of Reference Example 1 and the powder coating of Reference Example 2 were thin films formed by products obtained by thermally decomposing propane gas by a thermal CVD method in a rotary kiln type reactor. From this, it can be said that the powder coating of Example 4 is a coating different from the coating manufactured in the rotary kiln type reactor.
  • Example 7 (Coating analysis 4) Analysis of the powder of Example 7 confirmed that a number of SiC crystals were present on the surface of the Si particles. Due to the presence of SiC crystals, the powder coating of Example 7 is estimated to have a smaller surface area of Si particles than the powder coating of Example 1. In the powder production conditions of Example 1 and Example 7, Example 7 was closer to the cooling gas jet outlet than in Example 1 in the plasma generator, and the carbon source gas and Si particles were in contact with each other. It is inferred that SiC was easily generated in the powder of Example 7 at a high temperature. In addition, when a large amount of SiC is present, it is assumed that oxygen is difficult to be introduced into the coating film in the oxygen introduction process during production. Therefore, it can be inferred that the powder film of Example 7 has a smaller amount of oxygen introduced into the film than the powder film of Example 1, and the ester skeleton contained in the film.
  • the powder of Example 2 is composed of a Si particle bonded body having no carbon-containing coating.
  • the powder of Example 3, the powder of Example 4, and the powder of Example 6 are made of a Si particle combination having a carbon-containing coating. From the results of the oxygen content, it was found that the powder in which the carbon-containing film was formed had a lower oxygen content in the whole powder than the powder in which the carbon-containing film was not formed. Therefore, it can be said that the oxidation of the whole powder is suppressed by the presence of the carbon-containing coating. Moreover, it was confirmed that the one with a higher C / Si ratio has a lower oxygen content in the whole powder. From this, it is presumed that the carbon-containing coating uniformly coats the entire Si particle combination when the C / Si ratio is high.
  • a 20 ⁇ m thick copper foil was prepared as a current collector.
  • the composition for negative electrode active material layers was placed on the surface of the copper foil, and the composition for negative electrode active material layers was applied to form a film using a doctor blade.
  • the copper foil coated with the negative electrode active material layer composition was dried to remove N-methyl-2-pyrrolidone by volatilization, and the negative electrode of Example A in which the negative electrode active material layer was formed on the copper foil surface was produced. did.
  • the mixture of polyacrylic acid and 4,4'-diaminodiphenylmethane used as the binder is a crosslinked polymer in which the dehydration reaction proceeds by drying and the polyacrylic acid is crosslinked with 4,4'-diaminodiphenylmethane. To change.
  • a lithium ion secondary battery (half cell) was produced using the negative electrode of Example A produced in the above procedure as a working electrode.
  • the counter electrode was a metal lithium foil.
  • a working electrode and a counter electrode, and a separator (Hoechst Celanese glass filter and Celgard “Celgard 2400”) interposed between the two electrodes were disposed to form an electrode body.
  • This electrode body was accommodated in a battery case (CR2032-type coin battery member, manufactured by Hosen Co., Ltd.).
  • Comparative Example A A negative electrode of Comparative Example A and a lithium ion secondary battery of Comparative Example A were produced in the same manner as in Example A, except that the powder of Reference Example 1 was used instead of the powder of Example 4.
  • the negative electrode of Example B was prepared in the same manner as the negative electrode of Example A, except that this mixture was dispersed in an appropriate amount of N-methyl-2-pyrrolidone to produce a slurry-like composition for negative electrode active material layer.
  • Manufactured And the lithium ion secondary battery of Example B was manufactured like the lithium ion secondary battery of Example A except having used the negative electrode of Example B.
  • Example D A lithium ion secondary battery of Example D was produced in the same manner as Example B except that the powder of Example 7 was used instead of the powder of Example 4.
  • the discharge capacity of the lithium ion secondary battery of Example A was larger than the discharge capacity of the lithium ion secondary battery of Comparative Example A. Since the Si particle combination contained in the powder of Example 4 used for the negative electrode of Example A has fibrous Si, the surface area is larger than that of the powder of Reference Example 1 used for the negative electrode of Comparative Example A. It is estimated that the discharge capacity of the lithium ion secondary battery has increased.
  • the initial efficiency was calculated from each charge capacity and discharge capacity.
  • the initial efficiency was calculated from the following formula.
  • Initial efficiency (%) (charge capacity / discharge capacity) ⁇ 100
  • the initial efficiency of the lithium ion secondary battery of Example A was 82.3%, and the initial efficiency of the lithium ion secondary battery of Comparative Example A was 78.7%. From this, it was confirmed that the lithium ion secondary battery of Example A using the Si particle combination had higher initial efficiency than the lithium ion secondary battery of Comparative Example A using the powder of Reference Example 1. It was done.
  • the discharge curve of the lithium ion secondary battery of Comparative Example A shows 0 mAh / g ⁇ It was observed that the potential was higher than the discharge curve of the lithium ion secondary battery of Example A at around 300 mAh / g. This potential is presumed to be due to the decomposition current of the electrolyte. In the discharge curve of the lithium ion secondary battery of Example A, the high potential portion was not observed. Therefore, it is considered that the decomposition of the electrolytic solution was suppressed in the lithium ion secondary battery of Example A.
  • the coating of the negative electrode active material has an ester skeleton, thereby suppressing the decomposition of the electrolytic solution.
  • the coating having an ester skeleton is presumed to be similar in structure to the organic solvent used in the electrolytic solution and have a reduction potential window similar to that of the organic solvent used in the electrolytic solution. Therefore, it is presumed that decomposition of the electrolytic solution is suppressed by the presence of the coating film having an ester skeleton on the surface of the negative electrode active material. From FIG. 18, it was confirmed that the lithium ion secondary battery including the negative electrode including the negative electrode active material or the second negative electrode active material of the present invention is excellent in battery capacity and initial efficiency.
  • the powder of Example 4 used in the lithium ion secondary battery of Example B and the powder of Example 3 used in the lithium ion secondary battery of Example C In comparison with the powder of Example 7 used in the lithium ion secondary battery of Example D, in the powder of Example 4, an Si particle composite having a combination of a plurality of Si particles and a plurality of fibrous Si Many were observed. In the powder of Example 3 and the powder of Example 7, many Si particle combinations having a combination of one Si particle and one fibrous Si were observed. From this, it is surmised that in the Si particle combination having a combination of a plurality of Si particles and a plurality of fibrous Si, the irreversible capacity is reduced and the initial efficiency is increased in the lithium ion secondary battery.
  • the discharge curve of the lithium ion secondary battery of Example D shows 0 mAh on the X axis. It was found that the potential was higher than the discharge curves of the lithium ion secondary batteries of Examples B and C in the vicinity of / g to 300 mAh / g. This potential is presumed to be due to the decomposition current of the electrolyte. In the discharge curves of the lithium ion secondary batteries of Example B and Example C, the high potential portion was not observed. Therefore, in the lithium ion secondary batteries of Example B and Example C, the decomposition of the electrolyte was suppressed. It is thought that.
  • the proportion of the powder coating of Example 7 having an ester skeleton is considered to be smaller than the proportion of the coating of the powder coating of Example 4 and Example 3. Therefore, it is presumed that the effect of suppressing the decomposition of the electrolytic solution is increased when the powder film has more ester skeletons.
  • Example B From FIG. 20, it was confirmed that the lithium ion secondary batteries of Example B, Example C, and Example D had a capacity retention rate of 80% or more even in the 20th cycle and were excellent in capacity retention rate. .
  • the lithium ion secondary battery of Example B had a capacity retention rate of 90% or more even at the 20th cycle, and was confirmed to be particularly excellent.
  • the powder of Example 4 used for the lithium ion secondary battery of Example B many Si particle combinations having a combination of a plurality of Si particles and a plurality of fibrous Si were observed.
  • the Si particle combination having a combination of a plurality of Si particles and a plurality of fibrous Si includes a large number of voids, even if Si expands and contracts during charge and discharge, the voids serve as a buffering factor, and the Si particles It is speculated that the variation in the overall size of the conjugate was particularly small. Therefore, it is considered that the capacity retention rate of the lithium ion secondary battery of Example B was particularly high. From FIG. 20, it was confirmed that the lithium ion secondary battery of the present invention is excellent in capacity retention rate.
  • Example 8 The powder of Example 8 was produced using an apparatus obtained by improving a part of the plasma generator shown in FIG.
  • the cooling gas supply pipes 91 in FIG. 2 are a plurality of supply pipes, a part is a rare gas supply pipe, and the other part is a carbon source gas supply pipe.
  • the distance between the opening of the rare gas supply pipe and the opening of the plasma generator 11 was 150 mm.
  • the distance between the opening of the carbon source gas supply pipe and the opening of the plasma generator 11 was 200 mm.
  • argon gas as a process gas was added at 60 L / min. At 5 L / min. As an inner gas. At a flow rate of 3 L / min. Supplied with.
  • argon gas was supplied at 20 L / min. Supplied with. From the carbon source gas supply pipe, 0.096 L / min. Of methane gas is used as the carbon source gas. Supplied with.
  • the flow rate of methane gas was measured using a flow meter using a thermal flow sensor (manufactured by Cofrock, small mass flow controller Model EX250S series). At this time, power was supplied from the power supply device, and a magnetic field with a frequency of 4 MHz was applied to the coil to generate plasma with an output of 10 kW.
  • the pressure in the plasma generator was atmospheric pressure. After the plasma was stabilized, the powder feeder was operated, and the raw material Si powder was added at 400 mg / min.
  • Example 8 which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 0.3.
  • Example 9 Methane gas is used as the carbon source gas at 0.22 L / min.
  • the powder of Example 9 was produced in the same manner as the powder of Example 8 except that the powder was supplied.
  • C / Si which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 0.69.
  • Example 10 Methane gas as the carbon source gas is 0.33 L / min.
  • the powder of Example 10 was produced in the same manner as the powder of Example 8 except that it was supplied.
  • C / Si which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 1.03.
  • Example 11 Methane gas is used as a carbon source gas at 0.8 L / min.
  • the powder of Example 11 was produced in the same manner as the powder of Example 8 except that the powder was supplied in step VII.
  • C / Si which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 2.5.
  • Example 12 Methane gas is used as the carbon source gas at 0.96 L / min.
  • a powder of Example 12 was produced in the same manner as the powder of Example 8 except that the powder was supplied in step VII.
  • C / Si which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 3.0.
  • Example 13 Methane gas is used as a carbon source gas at 1.24 L / min.
  • the powder of Example 13 was produced in the same manner as the powder of Example 8 except that the powder was supplied in step VII.
  • C / Si which is the ratio of the number of moles of carbon source gas supplied per unit time to the number of moles of raw material Si powder supplied per unit time, was 3.87.
  • Example 14 The raw material Si powder was 100 mg / min. The methane gas was introduced into the plasma together with the carrier gas at a rate of 0.08 L / min. A powder of Example 14 was produced in the same manner as the powder of Example 8, except that the powder was supplied in step VII.
  • C / Si which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 1.0.
  • Example 15 The raw material Si powder was 700 mg / min. The methane gas was introduced into the plasma together with the carrier gas at a rate of 0.56 L / min. The powder of Example 15 was produced in the same manner as the powder of Example 14, except that the powder was supplied in step S2. C / Si, which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 1.0.
  • Example 16 The plasma output was 15 kW, the distance between the opening of the carbon source gas supply pipe and the opening in the plasma generator was 350 mm, and methane gas as the carbon source gas was 0.32 L / min.
  • a powder of Example 16 was produced in the same manner as the powder of Example 8, except that the powder was supplied in (4).
  • C / Si which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 1.0.
  • Example 17 A powder of Example 17 was produced in the same manner as the powder of Example 16, except that the plasma output was 20 kW.
  • C / Si which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 1.0.
  • the mechanism having a structure derived from CH 2 and / or CH 3 is as follows. Conceivable. In the production of the powders of Comparative Examples 1 and 2, the distance between the opening of the cooling gas supply pipe and the opening in the plasma generator was 200 mm, whereas in the production of the powders of Examples 16 and 17, The distance between the opening of the rare gas supply pipe and the opening in the plasma generator was 150 mm, and the distance between the opening of the carbon source gas supply pipe and the opening in the plasma generator was 350 mm.

Abstract

Provided are novel Si particle aggregates and a method for producing the same. These Si particle aggregates are characterized by having Si particles and fibrous Si bonded to the Si particles, and are further characterized in that the grain size of the Si particles is greater than the fiber diameter of the fibrous Si.

Description

Ｓｉ粒子結合体及びその製造方法Si particle bonded body and manufacturing method thereof
　本発明は、新規なＳｉ粒子及びその製造方法、並びに新規なＳｉ粒子を用いた非水電解質二次電池に関するものである。 The present invention relates to a novel Si particle, a method for producing the same, and a non-aqueous electrolyte secondary battery using the novel Si particle.
　Ｓｉは、太陽電池の材料、二次電池用活物質材料、感光体材料など様々な用途に用いられている。 Si is used in various applications such as solar cell materials, secondary battery active material, and photoreceptor materials.
　近年、非水電解質二次電池の一つであるリチウムイオン二次電池の負極活物質として、炭素材料の理論容量を大きく超える充放電容量を持つ珪素や珪素化合物などの珪素系材料が検討されている。例えば、特許文献１（国際公開第２０１４／０８０６０８号）には、ＣａＳｉ２と酸とを反応させてＣａを除去して得られた層状ポリシランを主成分とする層状シリコン化合物を合成すること、当該層状シリコン化合物を３００℃以上で加熱して水素を離脱させたシリコン材料を製造すること、及び、当該シリコン材料を活物質として具備するリチウムイオン二次電池が記載されている。 In recent years, silicon-based materials such as silicon and silicon compounds having a charge / discharge capacity that greatly exceeds the theoretical capacity of carbon materials have been studied as negative electrode active materials for lithium ion secondary batteries, which are one of non-aqueous electrolyte secondary batteries. Yes. For example, Patent Document 1 (International Publication No. 2014/080608) synthesizes a layered silicon compound mainly composed of layered polysilane obtained by reacting CaSi 2 with an acid to remove Ca, A silicon material in which a layered silicon compound is heated at 300 ° C. or higher to release hydrogen and a lithium ion secondary battery including the silicon material as an active material is described.
　一般に、珪素系材料を負極活物質として用いると、充放電におけるリチウム（Ｌｉ）の吸蔵及び放出に伴って、負極活物質が膨張及び収縮することが知られている。負極活物質が膨張及び収縮することで、負極活物質を集電体に保持するバインダーに負荷がかかる。それにより、負極活物質と集電体との密着性の低下や、電極内の導電パスの破壊のおそれがある。その結果、電極の抵抗が増大し、電池の容量低下が生じるおそれがある。また、膨張と収縮の繰り返しにより、負極活物質に歪が生じて、微細化し、電極から脱離するおそれがある。そのため、負極活物質の膨張及び収縮は、電池のサイクル特性低下にも影響する。負極活物質である珪素系材料の膨張及び収縮の影響を抑制するために、例えば、珪素系材料の微粒子化が検討されている。 Generally, when a silicon-based material is used as a negative electrode active material, it is known that the negative electrode active material expands and contracts with the insertion and extraction of lithium (Li) during charge and discharge. As the negative electrode active material expands and contracts, a load is applied to the binder that holds the negative electrode active material on the current collector. As a result, the adhesion between the negative electrode active material and the current collector may be reduced, or the conductive path in the electrode may be destroyed. As a result, the resistance of the electrode increases and the capacity of the battery may be reduced. In addition, the negative electrode active material may be distorted due to repeated expansion and contraction, and may be refined and detached from the electrode. Therefore, the expansion and contraction of the negative electrode active material also affects the deterioration of the cycle characteristics of the battery. In order to suppress the influence of expansion and contraction of the silicon-based material that is the negative electrode active material, for example, the formation of fine particles of the silicon-based material has been studied.
　珪素系材料の微粒子化方法としては、ノズルから流下する溶融Ｓｉにガスを吹き付けて溶融Ｓｉの微小液滴を形成するガスアトマイズ法や溶融Ｓｉを高速回転する皿形ディスクに入れ遠心力を作用させて小滴として飛散させる回転ディスク法、などが知られている。 As a method for atomizing silicon-based material, gas atomization method in which gas is blown to molten Si flowing down from a nozzle to form fine droplets of molten Si, or molten Si is put into a dish-shaped disk that rotates at high speed, and centrifugal force is applied. A rotating disk method that scatters droplets is known.
　特許文献２（特開２００５－３２０１９５号公報）には、回転ディスク法によって粒径が１０μｍ～５０μｍであるＳｉ粒子を製造する方法が開示されている。また、特許文献２には、回転ディスク法で製造された粒径が１０μｍ～５０μｍのＳｉ粒子を含む分散液を製造し、その分散液を加圧して小径ノズルを通過させる操作を繰り返すことによって粒径を小さくしたナノメータサイズのＳｉ粒子を得ることが開示されている。 Patent Document 2 (Japanese Patent Laid-Open No. 2005-320195) discloses a method for producing Si particles having a particle diameter of 10 μm to 50 μm by a rotating disk method. Patent Document 2 discloses that a dispersion containing Si particles having a particle diameter of 10 μm to 50 μm manufactured by the rotating disk method is manufactured, and the operation is performed by pressing the dispersion and passing it through a small-diameter nozzle. It is disclosed to obtain nanometer-sized Si particles with a reduced diameter.
国際公開第２０１４／０８０６０８号International Publication No. 2014/080608 特開２００５－３２０１９５号公報JP 2005-320195 A
　しかしながら、リチウムイオン二次電池の負極活物質に対する要求は増加しており、より優れた負極活物質となり得る新たなＳｉ粒子の提供が熱望されている。本発明は、かかる事情に鑑みてなされたものであり、負極活物質となり得る新たな形態のＳｉ粒子を提供することを目的とする。 However, the demand for the negative electrode active material of the lithium ion secondary battery is increasing, and there is a strong desire to provide new Si particles that can be a better negative electrode active material. This invention is made | formed in view of this situation, and it aims at providing the Si particle of the new form which can become a negative electrode active material.
　本発明者は、プラズマ内に原料Ｓｉ粉末を投入し、原料Ｓｉ粉末を気体又は液体状態にすること、そして、プラズマ外を冷却し、プラズマ内外の極端な温度差を利用して、生成物を急冷しＳｉ粒子を得ることを想起した。本発明者が、試行錯誤を繰り返して鋭意検討したところ、原料Ｓｉ粉末を導入流にて、プラズマ内に導入し、導入流がプラズマ内を通過した後の通過流を通過流に対向する冷却ガス流で冷却することで、新規な形態のＳｉ粒子結合体が得られたことを確認した。また、冷却時にＳｉに炭素源ガスを接触させることによって、上記Ｓｉ粒子結合体に炭素含有被膜を形成させることができることを確認した。特に、プラズマ出力が５ｋＷ以上１５ｋＷ未満の条件下で、または冷却ガス中の炭素源ガスの供給位置を特定することで、特別な炭素含有被膜を形成させることができることを見出した。そして、本発明者はかかる知見に基づき、Ｓｉ粒子結合体又は被膜付きＳｉ粒子結合体を具備する負極を製造し、該負極を具備するリチウムイオン二次電池が正常に動作することを確認して、本発明を完成させた。 The present inventor puts raw material Si powder into the plasma, turns the raw material Si powder into a gas or liquid state, cools the outside of the plasma, and uses the extreme temperature difference between the inside and outside of the plasma to produce the product. It recalled that it was rapidly cooled to obtain Si particles. As a result of repeated trial and error, the inventor has conducted intensive studies and introduced raw material Si powder into the plasma as an introduction flow, and a cooling gas that opposes the passage flow after the introduction flow has passed through the plasma. It was confirmed that a new form of Si particle combination was obtained by cooling with a flow. Further, it was confirmed that a carbon-containing film can be formed on the Si particle bonded body by bringing a carbon source gas into contact with Si during cooling. In particular, it has been found that a special carbon-containing film can be formed under conditions where the plasma output is 5 kW or more and less than 15 kW, or by specifying the supply position of the carbon source gas in the cooling gas. And based on this knowledge, this inventor manufactures the negative electrode which comprises Si particle | grain combination body or a Si particle | grain coupling body with a film, and confirms that the lithium ion secondary battery which comprises this negative electrode operate | moves normally. The present invention has been completed.
　すなわち、本発明のＳｉ粒子結合体は、Ｓｉ粒子と、Ｓｉ粒子に結合する繊維状Ｓｉと、を有し、Ｓｉ粒子の粒径は、繊維状Ｓｉの繊維径よりも大きいことを特徴とする。 That is, the Si particle bonded body of the present invention has Si particles and fibrous Si bonded to the Si particles, and the particle size of the Si particles is larger than the fiber diameter of the fibrous Si. .
　本発明により、負極活物質となり得る新たな形態のＳｉ粒子を提供できる。 According to the present invention, it is possible to provide a new form of Si particles that can be a negative electrode active material.
本発明のＳｉ粒子結合体の模式図である。It is a schematic diagram of the Si particle combination of the present invention. プラズマ発生装置の模式図である。It is a schematic diagram of a plasma generator. 実施例１の粉末断面の走査型電子顕微鏡(以下、適宜、断面ＳＥＭと称す。)観察結果である。2 is a result of observation of a cross section of a powder of Example 1 by a scanning electron microscope (hereinafter, appropriately referred to as a cross section SEM). 図３の１０倍の倍率での断面ＳＥＭ観察結果である。It is a cross-sectional SEM observation result in the magnification of 10 times of FIG. 図３の１００倍の倍率での断面ＳＥＭ観察結果である。It is a cross-sectional SEM observation result in the magnification of 100 times of FIG. 実施例１の粉末の透過型電子顕微鏡（以下、適宜、ＴＥＭと称す。）観察結果である。It is an observation result of the transmission electron microscope (hereinafter referred to as TEM as appropriate) of the powder of Example 1. 実施例１の粉末のＳｉ粒子の粒度分布図である。3 is a particle size distribution diagram of Si particles of the powder of Example 1. FIG. 実施例１の粉末のエネルギー分散型Ｘ線分光法(以下、適宜、ＥＤＳ（Ｅｎｅｒｇｙ　Ｄｉｓｐｅｒｓｉｖｅ　Ｘ－ｒａｙ　Ｓｐｅｃｔｒｏｓｃｏｐｙ）と称す。)による観察結果である。It is an observation result of the powder of Example 1 by energy dispersive X-ray spectroscopy (hereinafter referred to as EDS (Energy Dispersive X-ray Spectroscopy) as appropriate). 図８の観察結果を示す模式図である。It is a schematic diagram which shows the observation result of FIG. 実施例１の粉末のＴＥＭ観察結果を示す模式図である。4 is a schematic diagram showing a TEM observation result of the powder of Example 1. FIG. 図１０における繊維状Ｓｉ２０の電子エネルギー損失分光法(以下、適宜ＥＥＬＳ（Ｅｌｅｃｔｒｏｎ　Ｅｎｅｒｇｙ－Ｌｏｓｓ　Ｓｐｅｃｔｒｏｓｃｏｐｙ）と称す。)による観察結果である。FIG. 10 is an observation result by electron energy loss spectroscopy (hereinafter referred to as EELS (Electron Energy-Loss Spectroscopy) as appropriate) of the fibrous Si 20 in FIG. 図１１の観察結果を示す模式図である。It is a schematic diagram which shows the observation result of FIG. 実施例１の粉末、比較例１の粉末及び比較例２の粉末のＸ線光電子分光法（以下、適宜、ＸＰＳ（Ｘ－ｒａｙ　Ｐｈｏｔｏｅｌｅｃｔｒｏｎ　Ｓｐｅｃｔｒｏｓｃｏｐｙ）と称す。）の測定結果である。It is a measurement result of X-ray photoelectron spectroscopy (hereinafter referred to as XPS (X-ray Photoelectron Spectroscopy) as appropriate) of the powder of Example 1, the powder of Comparative Example 1, and the powder of Comparative Example 2. 実施例１の粉末、比較例１の粉末及び比較例２の粉末における各被膜のラマン分光法によるラマンスペクトルである。It is a Raman spectrum by the Raman spectroscopy of each film in the powder of Example 1, the powder of Comparative Example 1, and the powder of Comparative Example 2. 実施例１の粉末、実施例３の粉末、実施例４の粉末における各被膜のＸＰＳ測定結果である。It is an XPS measurement result of each film in the powder of Example 1, the powder of Example 3, and the powder of Example 4. 実施例４の粉末、参考例１の粉末及び参考例２の粉末の各被膜の熱分解ガスクロマトグラフィー（Ｐｙｒｏｌｙｓｉｓ　Ｇａｓ　Ｃｈｒｏｍａｔｏｇｒａｐｈｙ、以下、適宜、Ｐｙ－ＧＣと称す。）の結果である。FIG. 5 shows the results of pyrolysis gas chromatography (Pyrolysis Gas Chromatography, hereinafter referred to as “Py-GC” as appropriate) of the coating films of the powder of Example 4, the powder of Reference Example 1, and the powder of Reference Example 2. FIG. 実施例１～４の粉末及び実施例６の粉末の粉末Ｘ線回折法（以下、適宜、ＸＲＤと称す。）による測定結果のＸＲＤチャートである。4 is an XRD chart of measurement results of powders of Examples 1 to 4 and Example 6 by a powder X-ray diffraction method (hereinafter referred to as XRD as appropriate). 実施例Ａ及び比較例Ａのリチウムイオン二次電池の充放電曲線である。It is a charging / discharging curve of the lithium ion secondary battery of Example A and Comparative Example A. 実施例Ｂ、実施例Ｃ及び実施例Ｄのリチウムイオン二次電池の充放電曲線である。It is a charging / discharging curve of the lithium ion secondary battery of Example B, Example C, and Example D. 実施例Ｂ、実施例Ｃ及び実施例Ｄのリチウムイオン二次電池のサイクル数と容量維持率の関係を示すグラフである。It is a graph which shows the relationship between the cycle number of the lithium ion secondary battery of Example B, Example C, and Example D, and a capacity | capacitance maintenance factor.
　以下に、本発明を実施するための最良の形態を説明する。なお、特に断らない限り、本明細書に記載された数値範囲「ｘ～ｙ」は、下限ｘおよび上限ｙをその範囲に含む。そして、これらの上限値および下限値、ならびに実施例中に列記した数値も含めてそれらを任意に組み合わせることで数値範囲を構成し得る。さらに数値範囲内から任意に選択した数値を上限、下限の数値とすることができる。 The best mode for carrying out the present invention will be described below. Unless otherwise specified, the numerical range “x to y” described in this specification includes the lower limit x and the upper limit y. The numerical range can be configured by arbitrarily combining these upper limit value and lower limit value and the numerical values listed in the examples. Furthermore, numerical values arbitrarily selected from the numerical value range can be used as upper and lower numerical values.
（Ｓｉ粒子結合体）
　本発明のＳｉ粒子結合体は、Ｓｉ粒子と、Ｓｉ粒子に結合する繊維状Ｓｉと、を有し、Ｓｉ粒子の粒径は、繊維状Ｓｉの繊維径よりも大きいことを特徴とする。 (Si particle combination)
The Si particle bonded body of the present invention has Si particles and fibrous Si bonded to the Si particles, and the particle size of the Si particles is larger than the fiber diameter of the fibrous Si.
　Ｓｉ粒子結合体の形態には、Ｓｉ粒子一個とそのＳｉ粒子に結合する繊維状Ｓｉ一個の組み合わせ、Ｓｉ粒子一個とそのＳｉ粒子に結合する繊維状Ｓｉ二個以上の組み合わせ、Ｓｉ粒子二個とその両者に結合する繊維状Ｓｉ一個の組み合わせ、複数のＳｉ粒子と複数の繊維状Ｓｉとが結合する組み合わせが含まれる。Ｓｉ粒子結合体において、繊維状Ｓｉは、複数のＳｉ粒子に結合していることが好ましい。また、Ｓｉ粒子結合体は、複数のＳｉ粒子と複数の繊維状Ｓｉとが結合する組み合わせが好ましい。 The form of the Si particle combination includes a combination of one Si particle and one fibrous Si bonded to the Si particle, a combination of one Si particle and two or more fibrous Si bonded to the Si particle, two Si particles, A combination of one fibrous Si bonded to both of them and a combination of a plurality of Si particles and a plurality of fibrous Si are included. In the Si particle bonded body, the fibrous Si is preferably bonded to a plurality of Si particles. In addition, the Si particle bonded body is preferably a combination in which a plurality of Si particles and a plurality of fibrous Si are bonded.
　Ｓｉ粒子結合体は繊維状Ｓｉを含むため、Ｓｉ粒子の表面積に比べて、Ｓｉ粒子結合体の表面積は格段に大きい。 Since the Si particle bonded body contains fibrous Si, the surface area of the Si particle bonded body is much larger than the surface area of the Si particle.
　Ｓｉ粒子の粒径は、１０ｎｍ以上１５００ｎｍ以下であることが好ましく、２０ｎｍ以上１２００ｎｍ以下であることがより好ましく、３０ｎｍ以上１０００ｎｍ以下であることがさらに好ましい。ここでのＳｉ粒子の粒径は、Ｓｉ粒子結合体を走査型電子顕微鏡や透過型電子顕微鏡などの電子顕微鏡で観察した場合における、観察されたＳｉ粒子像の長径を意味する。 The particle diameter of the Si particles is preferably 10 nm or more and 1500 nm or less, more preferably 20 nm or more and 1200 nm or less, and further preferably 30 nm or more and 1000 nm or less. The particle size of the Si particles here means the major axis of the observed Si particle image when the Si particle combination is observed with an electron microscope such as a scanning electron microscope or a transmission electron microscope.
　複数のＳｉ粒子を有するＳｉ粒子結合体、又は、Ｓｉ粒子結合体の凝集体若しくは集合体におけるＳｉ粒子の平均粒径は、１０ｎｍ以上３００ｎｍ以下であることが好ましく、２０ｎｍ以上２００ｎｍ以下であることがより好ましく、５０ｎｍ以上１５０ｎｍ以下であることがさらに好ましい。ここでの平均粒径は、上記Ｓｉ粒子の粒径のＤ５０又は算術平均値を意味する。ここで、Ｄ５０とはレーザー回析法による粒度分布測定における体積分布の積算値が５０％に相当する粒径のことである。つまり、Ｄ５０とは、体積基準で測定したメディアン径を意味する。算術平均値は、例えば、２００個のＳｉ粒子の粒径の測定結果から求めることができる。 The average particle diameter of the Si particles in the Si particle bonded body having a plurality of Si particles, or the aggregate or aggregate of the Si particle bonded bodies is preferably 10 nm to 300 nm, and preferably 20 nm to 200 nm. More preferably, it is 50 nm or more and 150 nm or less. Here the average particle size of the means D 50 or the arithmetic mean value of the particle size of the Si particles. Here, D 50 is a particle size corresponding to an integrated value of volume distribution in the particle size distribution measurement by laser diffraction method of 50%. That is, the D 50, means the median size measured by volume. The arithmetic average value can be obtained, for example, from the measurement result of the particle size of 200 Si particles.
　Ｓｉ粒子の形状は、特に限定されないが、球形、楕円球形、液滴形状が例示される。 The shape of the Si particles is not particularly limited, and examples thereof include a spherical shape, an elliptical spherical shape, and a droplet shape.
　繊維状Ｓｉの繊維径は、４ｎｍ以上２５ｎｍ以下であることが好ましく、５ｎｍ以上２０ｎｍ以下であることがより好ましく、６ｎｍ以上１８ｎｍ以下であることがさらに好ましい。繊維状Ｓｉの繊維径は、Ｓｉ粒子結合体を走査型電子顕微鏡や透過型電子顕微鏡などの電子顕微鏡で観察した場合における、観察された繊維状Ｓｉ像の繊維径を意味する。 The fiber diameter of fibrous Si is preferably 4 nm or more and 25 nm or less, more preferably 5 nm or more and 20 nm or less, and further preferably 6 nm or more and 18 nm or less. The fiber diameter of fibrous Si means the fiber diameter of the observed fibrous Si image when the Si particle combination is observed with an electron microscope such as a scanning electron microscope or a transmission electron microscope.
　繊維状Ｓｉの繊維長は、１０ｎｍ以上２０μｍ以下であることが好ましく、１５ｎｍ以上５μｍ以下であることがより好ましく、２０ｎｍ以上２μｍ以下であることがさらに好ましい。繊維状Ｓｉの繊維長は、Ｓｉ粒子結合体を走査型電子顕微鏡や透過型電子顕微鏡などの電子顕微鏡で観察した場合における、観察された繊維状Ｓｉ像の繊維長を意味する。 The fiber length of the fibrous Si is preferably 10 nm or more and 20 μm or less, more preferably 15 nm or more and 5 μm or less, and further preferably 20 nm or more and 2 μm or less. The fiber length of fibrous Si means the fiber length of the observed fibrous Si image when the Si particle combination is observed with an electron microscope such as a scanning electron microscope or a transmission electron microscope.
　繊維状Ｓｉは、繊維径に比べて繊維長が長い繊維状であれば、形状は特に限定されない。繊維状Ｓｉは、その繊維長方向の端部においてＳｉ粒子に結合している。 The shape of the fibrous Si is not particularly limited as long as the fiber has a fiber length longer than the fiber diameter. Fibrous Si is bonded to Si particles at the end in the fiber length direction.
　Ｓｉ粒子の粒径は、繊維状Ｓｉの繊維径より大きい。Ｓｉ粒子の粒径は、繊維径の２倍以上３００倍以下であることが好ましく、４倍以上１００倍以下であることがより好ましく、６倍以上２０倍以下であることがさらに好ましい。 The particle diameter of Si particles is larger than the fiber diameter of fibrous Si. The particle size of the Si particles is preferably 2 to 300 times the fiber diameter, more preferably 4 to 100 times, and even more preferably 6 to 20 times.
　複数のＳｉ粒子結合体は凝集して凝集体の形態となる場合がある。凝集体は、全体の長手方向の大きさが１μｍ以上１５０μｍ以下であることが好ましく、３μｍ以上１００μｍ以下であることがより好ましく、５μｍ以上５０μｍ以下であることがさらに好ましい。凝集体全体の長手方向の大きさは、凝集体を走査型電子顕微鏡や透過型電子顕微鏡などの電子顕微鏡で観察した場合における、観察された凝集体像の長手方向の長さを意味する。 A plurality of Si particle aggregates may aggregate to form aggregates. The size of the aggregate in the longitudinal direction is preferably 1 μm or more and 150 μm or less, more preferably 3 μm or more and 100 μm or less, and further preferably 5 μm or more and 50 μm or less. The size of the aggregate in the longitudinal direction means the length in the longitudinal direction of the observed aggregate image when the aggregate is observed with an electron microscope such as a scanning electron microscope or a transmission electron microscope.
　Ｓｉ粒子結合体には、その形態から、空隙が含まれる。特に、複数のＳｉ粒子と複数の繊維状Ｓｉとが結合する組み合わせを有するＳｉ粒子結合体は、多数の空隙を含む。Ｓｉ粒子結合体を非水電解質二次電池の負極活物質として使用した場合、充放電時にＳｉが膨張、収縮しても、空隙が緩衝因子となるため、Ｓｉ粒子結合体の全体の大きさはほとんど変動しないことが予想される。 The Si particle bonded body includes voids due to its form. In particular, a Si particle bonded body having a combination in which a plurality of Si particles and a plurality of fibrous Si are bonded includes a large number of voids. When the Si particle combination is used as a negative electrode active material for a non-aqueous electrolyte secondary battery, even if Si expands and contracts during charge and discharge, the voids serve as a buffering factor, so the overall size of the Si particle combination is Expect little change.
　図１に本発明のＳｉ粒子結合体の模式図を示す。図１において、各繊維状Ｓｉ２０は、複数のＳｉ粒子１０に結合して、１個のＳｉ粒子結合体４０を形成している。また、図１に示すＳｉ粒子結合体４０は、空隙３０を有する。図１においては、複数のＳｉ粒子１０に結合する複数の繊維状Ｓｉ２０は網目状構造を形成している。 FIG. 1 shows a schematic diagram of a bonded Si particle of the present invention. In FIG. 1, each fibrous Si 20 is bonded to a plurality of Si particles 10 to form one Si particle bonded body 40. Further, the Si particle bonded body 40 shown in FIG. In FIG. 1, a plurality of fibrous Si 20 bonded to a plurality of Si particles 10 forms a network structure.
　Ｓｉ粒子結合体に含まれるＳｉは、Ｓｉ結晶を有することが好ましい。さらに、Ｓｉ粒子及び繊維状Ｓｉは両者ともＳｉ結晶を含むことが好ましい。Ｓｉ粒子結合体をＸＲＤで測定し、そのＸＲＤ測定データにおいてＳｉ結晶のピークが確認できればＳｉ粒子結合体にＳｉ結晶が含まれることがわかる。 It is preferable that Si contained in the Si particle bonded body has Si crystal. Further, both the Si particles and the fibrous Si preferably contain Si crystals. When the Si particle combination is measured by XRD, and the peak of the Si crystal can be confirmed in the XRD measurement data, it can be understood that the Si particle combination includes the Si crystal.
（被膜付きＳｉ粒子結合体）
　本発明の被膜付きＳｉ粒子結合体は、上記Ｓｉ粒子結合体と、Ｓｉ粒子結合体の表面に配置された炭素含有被膜と、を有することを特徴とする。 (Si particle bonded body with coating)
The coated Si particle bonded body of the present invention is characterized by having the above Si particle bonded body and a carbon-containing film disposed on the surface of the Si particle bonded body.
　Ｓｉ粒子結合体は上記で説明したものである。Ｓｉ粒子結合体の表面とは、Ｓｉ粒子の表面、繊維状Ｓｉの表面及びＳｉ粒子と繊維状Ｓｉとの結合部の表面を指す。炭素含有被膜はＳｉ粒子結合体の表面全体に配置されていることが好ましい。Ｓｉ粒子結合体の表面に被膜が形成されることによって、表面が保護されて、酸素含有雰囲気下にあってもＳｉ粒子結合体が酸化されにくい。また、Ｓｉ粒子結合体の表面に被膜が形成されることによって、Ｓｉ粒子結合体の構造が保持されやすい。 The Si particle combination is as described above. The surface of the Si particle bonded body refers to the surface of the Si particles, the surface of the fibrous Si, and the surface of the bonded portion between the Si particles and the fibrous Si. The carbon-containing coating is preferably disposed on the entire surface of the Si particle bonded body. By forming a film on the surface of the Si particle bonded body, the surface is protected and the Si particle bonded body is hardly oxidized even in an oxygen-containing atmosphere. Moreover, the structure of the Si particle bonded body is easily maintained by forming a film on the surface of the Si particle bonded body.
　炭素含有被膜の厚みは、特に限定されない。炭素含有被膜の厚みは１ｎｍ以上２０ｎｍ以下が好ましく、１ｎｍ以上１０ｎｍ以下であることがより好ましく、１ｎｍ以上５ｎｍ以下であることがさらに好ましい。ここでの炭素含有被膜の厚みは、走査型電子顕微鏡や透過型電子顕微鏡などの電子顕微鏡で観察した場合における厚みを指す。 The thickness of the carbon-containing film is not particularly limited. The thickness of the carbon-containing coating is preferably 1 nm or more and 20 nm or less, more preferably 1 nm or more and 10 nm or less, and further preferably 1 nm or more and 5 nm or less. The thickness of the carbon-containing coating here refers to the thickness when observed with an electron microscope such as a scanning electron microscope or a transmission electron microscope.
　炭素含有被膜は、少なくとも炭素を有する。炭素含有被膜はさらに水素、酸素を含んでもよい。Ｓｉは導電性が低いため、炭素含有被膜を有することで導電性を向上できると推測される。なお、本発明の被膜付きＳｉ粒子結合体が電池の負極活物質として使用された場合、電池特性が向上できることが期待される。 The carbon-containing film has at least carbon. The carbon-containing film may further contain hydrogen and oxygen. Since Si has low conductivity, it is presumed that conductivity can be improved by having a carbon-containing film. In addition, when the coated Si particle combination of the present invention is used as a negative electrode active material of a battery, it is expected that battery characteristics can be improved.
　炭素含有被膜は、アモルファスカーボンを含むことが好ましい。アモルファスカーボンを含む炭素含有被膜を有する本発明の被膜付きＳｉ粒子結合体が電池の負極活物質として使用された場合、充放電時にＳｉの膨張、収縮が起こっても、炭素含有被膜がＳｉ粒子結合体の表面から剥がれにくいことが期待され、電池特性が向上できることが期待される。 The carbon-containing film preferably contains amorphous carbon. When the coated Si particle combination of the present invention having a carbon-containing coating containing amorphous carbon is used as the negative electrode active material of a battery, the carbon-containing coating is bonded to Si particles even if Si expands or contracts during charge and discharge. Expected to be difficult to peel off from the surface of the body and expected to improve battery characteristics.
　炭素含有被膜は、Ｃ、Ｈ、Ｏ元素を含む被膜であることが好ましい。炭素含有被膜をＸ線光電子分光法（ＸＰＳ）によって分析した場合、Ｃ１ｓ軌道の高分解能スペクトルにおいて、２８７ｅＶ～２９０ｅＶにピークを有することが好ましい。２８７ｅＶ～２９０ｅＶに観察されるピークはＯ＝Ｃ－Ｏに由来する。また、炭素含有被膜のラマン分光法によって得られるラマンスペクトルにおいて、１４２０ｃｍ－１～１４８０ｃｍ－１の範囲にピークトップを有することが好ましい。１４２０ｃｍ－１～１４８０ｃｍ－１の範囲に見られるピークトップは、ＣＨ２又はＣＨ３に由来する。 The carbon-containing film is preferably a film containing C, H, and O elements. When the carbon-containing coating is analyzed by X-ray photoelectron spectroscopy (XPS), it preferably has a peak at 287 eV to 290 eV in the high resolution spectrum of the C1s orbit. The peak observed between 287 eV and 290 eV is derived from O = CO. Further, in the Raman spectrum obtained by Raman spectroscopy of the carbon-containing film, it is preferable to have a peak top in the range of 1420 cm −1 to 1480 cm −1 . The peak tops found in the range of 1420 cm −1 to 1480 cm −1 are derived from CH 2 or CH 3 .
　炭素含有被膜がＸＰＳによるＣ１ｓ軌道の高分解能スペクトルにおいて、上記ピークを有することにより、炭素含有被膜はエステル骨格を有すると推測される。 It is presumed that the carbon-containing film has an ester skeleton when the carbon-containing film has the above peak in the high resolution spectrum of the C1s orbit by XPS.
　Ｃ、Ｈ、Ｏ元素を含む被膜は、２７０℃までの熱分解温度における熱分解ガスクロマトグラフ質量分析（以下、適宜、熱分解ＧＣ－ＭＳと称す。）において、テルペン類のフラグメントが検出されることが好ましい。 Films containing C, H, and O elements should detect terpene fragments in pyrolysis gas chromatograph mass spectrometry (hereinafter referred to as pyrolysis GC-MS as appropriate) at pyrolysis temperatures up to 270 ° C. Is preferred.
　本発明の被膜付きＳｉ粒子結合体は、Ｓｉ粒子結合体の表面に被膜が形成されているため、酸素含有雰囲気下にあってもＳｉ粒子結合体が酸化されにくい。本発明の被膜付きＳｉ粒子結合体の酸素含有量は１０％以下であることが好ましく、８％以下であることがより好ましく、６％以下であることがさらに好ましい。 In the coated Si particle bonded body of the present invention, since the film is formed on the surface of the Si particle bonded body, the Si particle bonded body is hardly oxidized even in an oxygen-containing atmosphere. The oxygen content of the coated Si particle conjugate of the present invention is preferably 10% or less, more preferably 8% or less, and even more preferably 6% or less.
（Ｓｉ粒子結合体及び被膜付きＳｉ粒子結合体の製造方法）
　本発明のＳｉ粒子結合体及び被膜付きＳｉ粒子結合体の製造方法を以下にまとめて説明する。 (Method for producing Si particle bonded body and coated Si particle bonded body)
The production method of the Si particle bonded body and the coated Si particle bonded body of the present invention will be described together below.
　本発明のＳｉ粒子結合体の製造方法は、原料Ｓｉ粉末を導入流にて、プラズマ出力が５ｋＷ以上１５ｋＷ未満であるプラズマ内に導入する工程と、導入流がプラズマ内を通過した後の通過流を通過流に対向する冷却ガス流で冷却する冷却工程と、を含むことを特徴とする。 The method for producing a Si particle bonded body of the present invention includes a step of introducing raw material Si powder into a plasma having a plasma output of 5 kW or more and less than 15 kW by an introduction flow, and a flow after the introduction flow has passed through the plasma. And a cooling step of cooling with a cooling gas flow facing the passing flow.
　本発明の被膜付きＳｉ粒子結合体の製造方法は、原料Ｓｉ粉末を導入流にて、プラズマ出力が５ｋＷ以上１５ｋＷ未満であるプラズマ内に導入する工程と、導入流がプラズマ内を通過した後の通過流を通過流に対向する炭素源ガスを含む冷却ガス流で冷却し、通過流内のＳｉを炭素源ガスと接触させてＳｉに炭素含有被膜を形成させる冷却工程と、を含むことを特徴とする。 The method for producing a coated Si particle assembly of the present invention includes a step of introducing raw material Si powder into a plasma having a plasma output of 5 kW or more and less than 15 kW by an introduction flow, and after the introduction flow has passed through the plasma. A cooling step of cooling the passing flow with a cooling gas flow containing a carbon source gas opposed to the passing flow, and bringing Si in the passing flow into contact with the carbon source gas to form a carbon-containing film on the Si. And
　原料Ｓｉ粉末は市販のＳｉ粉末を使用すればよい。原料Ｓｉ粉末のＤ５０は特に限定されないが、１μｍ～１００μｍが好ましく、１μｍ～４０μｍがより好ましく、２μｍ～１０μｍがさらに好ましい。原料Ｓｉ粉末のＤ５０が小さすぎると、静電気などにより原料Ｓｉ粉末を移動させにくいおそれがあり、原料Ｓｉ粉末のＤ５０が大きすぎると、原料Ｓｉ粉末を均一に移動させにくいおそれがあるし、またプラズマ内で原料Ｓｉ粉末の導入量全量を気化または液体状態にするのが困難になるおそれがある。Ｄ５０は粒度分布測定法によって計測できる。ここで、Ｄ５０とはレーザー回析法による粒度分布測定における体積分布の積算値が５０％に相当する粒子径のことである。つまり、Ｄ５０とは、体積基準で測定したメディアン径を意味する。 A commercially available Si powder may be used as the raw material Si powder. The D 50 of the raw material Si powder is not particularly limited, but is preferably 1 μm to 100 μm, more preferably 1 μm to 40 μm, and even more preferably 2 μm to 10 μm. When the raw material Si powder of D 50 is too small, the less likely to move the raw material Si powder due to static electricity or the like, the raw material Si powder of D 50 is too large, to have hardly a possibility that uniformly moves the raw material Si powder, In addition, it may be difficult to vaporize or make the entire amount of the raw material Si powder introduced into the liquid state in the plasma. D 50 can be measured by particle size distribution measurement method. Here, D 50 is a particle diameter corresponding to an integrated value of volume distribution in particle size distribution measurement by laser diffraction method corresponding to 50%. That is, the D 50, means the median size measured by volume.
　本発明のＳｉ粒子結合体及び被膜付きＳｉ粒子結合体の製造方法は、プラズマ発生装置を用いて実施される。プラズマは、アーク放電、多相アーク放電、高周波電磁誘導、マイクロ波加熱放電などで発生させればよい。 The manufacturing method of the Si particle combination and the coated Si particle combination of the present invention is carried out using a plasma generator. The plasma may be generated by arc discharge, multiphase arc discharge, high frequency electromagnetic induction, microwave heating discharge, or the like.
　高周波電磁誘導式のプラズマ発生装置の場合、その周波数は、例えば０．５ＭＨｚ～４００ＭＨｚの範囲内、好ましくは１ＭＨｚ～８０ＭＨｚの範囲内とすればよい。プラズマ出力は、５ｋＷ以上１５ｋＷ未満であり、５ｋＷ以上１０ｋＷ以下とすればより好ましい。プラズマ出力が５ｋＷ以上１５ｋＷ未満であれば、冷却ガスとして炭素源ガスを含むガスを用いる場合において、ＳｉＣが生成されにくい。 In the case of a high frequency electromagnetic induction type plasma generator, the frequency may be, for example, in the range of 0.5 MHz to 400 MHz, preferably in the range of 1 MHz to 80 MHz. The plasma output is 5 kW or more and less than 15 kW, and more preferably 5 kW or more and 10 kW or less. If the plasma output is 5 kW or more and less than 15 kW, SiC is hardly generated when a gas containing a carbon source gas is used as the cooling gas.
　プラズマ発生装置内の圧力は適宜設定すればよく、例えば１０ｋＰａ～大気圧の範囲内を例示できる。プラズマ出力やプラズマ発生装置内の圧力を変動させることで、Ｓｉ粒子の平均粒径を変化させることができる。例えば、プラズマ発生装置内の圧力を大気圧に近づけることで、Ｓｉ粒子の平均粒径を小さくすることができる。 The pressure in the plasma generator may be set as appropriate, for example, the range of 10 kPa to atmospheric pressure can be exemplified. The average particle diameter of the Si particles can be changed by changing the plasma output or the pressure in the plasma generator. For example, the average particle size of the Si particles can be reduced by bringing the pressure in the plasma generator close to atmospheric pressure.
　導入流はプラズマへ向かう気体の流動によって発生する。導入流としては、プラズマの安定性を考慮して、プラズマ下で使用し得る気体を主流とするのが好ましい。導入流を構成する気体、つまり、導入ガスとしては、ヘリウム、アルゴンなどの希ガスや水素が好ましい。導入ガス流量としては、２０Ｌ／ｍｉｎ．～１２０Ｌ／ｍｉｎ．を例示できる。 The introduction flow is generated by the flow of gas toward the plasma. As the introduction flow, in consideration of the stability of the plasma, a gas that can be used under the plasma is preferably used as the main flow. As the gas constituting the introduction flow, that is, the introduction gas, a rare gas such as helium or argon or hydrogen is preferable. As an introduction gas flow rate, 20 L / min. ~ 120 L / min. Can be illustrated.
　プラズマ発生装置の種類によるが、本発明のＳｉ粒子結合体及び被膜付きＳｉ粒子結合体の製造方法においては、導入ガスとして、原料Ｓｉ粉末を運搬するキャリヤーガス、キャリヤーガスとは別にコイル内に導入されるインナーガス、及び、プラズマ発生部位を不活性雰囲気下にするためのプロセスガスを採用するのが好ましい。 Depending on the type of plasma generator, in the method for producing the Si particle bonded body and coated Si particle bonded body of the present invention, as the introduced gas, it is introduced into the coil separately from the carrier gas carrying the raw Si powder and the carrier gas. It is preferable to employ an inner gas to be used and a process gas for bringing the plasma generation site into an inert atmosphere.
　キャリヤーガスの流量としては、１Ｌ／ｍｉｎ．～１０Ｌ／ｍｉｎ．を例示できる。キャリヤーガスの流量としては、１Ｌ／ｍｉｎ．～５Ｌ／ｍｉｎ．が好ましい。インナーガスの流量としては、１Ｌ／ｍｉｎ．～１０Ｌ／ｍｉｎ．を例示できる。インナーガスの流量としては、１Ｌ／ｍｉｎ．～５Ｌ／ｍｉｎ．が好ましい。プロセスガスの流量としては、１５Ｌ／ｍｉｎ．～１００Ｌ／ｍｉｎ．を例示できる。プロセスガスの流量としては、３０Ｌ／ｍｉｎ．～１００Ｌ／ｍｉｎ．が好ましい。導入流量は、キャリヤーガスの流量、インナーガスの流量及びプロセスガスの流量を合計したものとなる。 The carrier gas flow rate is 1 L / min. ~ 10L / min. Can be illustrated. The flow rate of the carrier gas is 1 L / min. ~ 5L / min. Is preferred. The flow rate of the inner gas is 1 L / min. ~ 10L / min. Can be illustrated. The flow rate of the inner gas is 1 L / min. ~ 5L / min. Is preferred. The flow rate of the process gas is 15 L / min. To 100 L / min. Can be illustrated. As the flow rate of the process gas, 30 L / min. To 100 L / min. Is preferred. The introduction flow rate is the sum of the carrier gas flow rate, the inner gas flow rate, and the process gas flow rate.
　また、プロセスガスには、アルゴンのみを用いることが好ましい。プロセスガスとしてアルゴンとヘリウムとの混合ガスを用いるとアルゴンのみをプロセスガスとして用いる場合に比べてプラズマ内の温度が高くなる。ヘリウムとアルゴンとの比率にもよるが、実施例の装置を用いる場合には、アルゴンのみをプロセスガスとして用いる場合のプラズマ内の温度は１０，０００℃程度であり、アルゴンとヘリウムとの混合ガスをプロセスガスとして用いる場合のプラズマ内の温度は１５，０００℃程度である。 In addition, it is preferable to use only argon as the process gas. When a mixed gas of argon and helium is used as the process gas, the temperature in the plasma becomes higher than when only argon is used as the process gas. Although depending on the ratio of helium and argon, when the apparatus of the embodiment is used, the temperature in the plasma when only argon is used as the process gas is about 10,000 ° C., and a mixed gas of argon and helium When using as a process gas, the temperature in the plasma is about 15,000 ° C.
　原料Ｓｉ粉末の供給速度は、５０ｍｇ／ｍｉｎ．～１０００ｍｇ／ｍｉｎ．が好ましく、５０ｍｇ／ｍｉｎ．～５００ｍｇ／ｍｉｎ．がより好ましい。原料Ｓｉ粉末の供給速度が速くなりすぎると、多くのＳｉ粉末が気化する。多くのＳｉ粉末の気化にプラズマの熱エネルギーが奪われプラズマ内の温度が低下しすぎる場合がある。 The feed rate of the raw material Si powder is 50 mg / min. -1000 mg / min. Is preferable, and 50 mg / min. ~ 500 mg / min. Is more preferable. If the supply speed of the raw material Si powder becomes too fast, a lot of Si powder is vaporized. There are cases where the thermal energy of the plasma is deprived by the vaporization of many Si powders and the temperature in the plasma is too low.
　冷却工程では、導入流がプラズマ内を通過した後の通過流が対向する冷却ガス流で冷却される。プラズマ内は高温状態であり、プラズマ外の雰囲気温度は室温であるので、通過流がプラズマ内からプラズマ外に出るだけで通過流は急激に冷却されることになる。またプラズマ発生装置の全体を冷却水などで冷却することによりプラズマ外の雰囲気温度をさらに下げることもできる。通過流に対向する冷却ガス流を通過流に向かって噴射させることによって、冷却ガス流と通過流とが良好に接触し、通過流が均一に冷却される。また、通過流に対向する冷却ガス流が通過流に向かって噴射されることにより、通過流中のＳｉが冷却ガス流に乗って対流する。 In the cooling process, the flow after the introduction flow passes through the plasma is cooled by the opposing cooling gas flow. Since the inside of the plasma is in a high temperature state and the ambient temperature outside the plasma is room temperature, the passing flow is rapidly cooled simply by going out of the plasma from the plasma. Further, the ambient temperature outside the plasma can be further lowered by cooling the entire plasma generator with cooling water or the like. By injecting the cooling gas flow facing the through flow toward the through flow, the cooling gas flow and the through flow are in good contact with each other, and the through flow is uniformly cooled. Further, the cooling gas flow facing the passing flow is injected toward the passing flow, so that Si in the passing flow rides on the cooling gas flow and convects.
　ここで、本発明のＳｉ粒子結合体の生成機構について考察する。プラズマ内の温度は、８，０００℃～２０，０００℃程度である。冷却工程において、まず２，０００℃～２，３００℃程度でＳｉの核が生成され、核を中心にして多数の粒子が生成すると考えられる。通過流の冷却に伴って、生成した粒子に他の粒子が凝集することで、粒子が成長すると考えられる。通過流中のＳｉが冷却ガス流に乗って対流すると、冷却程度の異なるＳｉ、つまり粒子径の異なるＳｉが対流中に互いに接触する。本発明のＳｉ粒子結合体は、粒子径の異なるＳｉが対流中に結合することによって形成されると推測される。なお、本発明のＳｉ粒子結合体における繊維状Ｓｉは、理由は不明であるが、粒子径が小さなＳｉ粒子が連なって繊維状Ｓｉになったものと考えられる。 Here, the generation mechanism of the Si particle combination of the present invention will be considered. The temperature in the plasma is about 8,000 ° C. to 20,000 ° C. In the cooling step, first, Si nuclei are generated at about 2,000 ° C. to 2,300 ° C., and it is considered that many particles are generated around the nuclei. It is considered that the particles grow as a result of the other particles agglomerating with the generated particles as the through flow is cooled. When Si in the passing flow rides on the cooling gas flow and convects, Si having different degrees of cooling, that is, Si having different particle diameters, come into contact with each other during convection. The Si particle bonded body of the present invention is presumed to be formed by bonding Si having different particle diameters during convection. Although the reason for the fibrous Si in the Si particle bonded body of the present invention is unknown, it is considered that Si particles having small particle diameters are connected to form fibrous Si.
　冷却ガスとしては、ヘリウム、アルゴンなどの希ガスが好ましい。冷却ガスの温度は室温でもよいし、室温以下でもよい。冷却ガスの流量としては、導入流よりも小さい流量であればよく、例えば０．１Ｌ／ｍｉｎ．～３０Ｌ／ｍｉｎ．の範囲内を例示できる。冷却ガスの流量は、０．２Ｌ／ｍｉｎ．以上２５Ｌ／ｍｉｎ．以下であることが好ましく、０．３Ｌ／ｍｉｎ．以上２０Ｌ／ｍｉｎ．以下であることがより好ましい。 The cooling gas is preferably a rare gas such as helium or argon. The temperature of the cooling gas may be room temperature or lower than room temperature. The flow rate of the cooling gas may be a flow rate smaller than the introduction flow, for example, 0.1 L / min. ~ 30 L / min. This can be illustrated as an example. The flow rate of the cooling gas is 0.2 L / min. 25 L / min. Or less, preferably 0.3 L / min. 20 L / min. The following is more preferable.
　被膜付きＳｉ粒子結合体を製造する場合は、冷却工程において、炭素源ガスを含む冷却ガス流で冷却し、通過流内のＳｉを炭素源ガスと接触させてＳｉに炭素含有被膜を形成させる。炭素源ガスを含む冷却ガス流を通過流に向かって噴射させる場合、プラズマ内に炭素源ガスが混入されないようにすることが好ましい。プラズマ内に炭素源ガスが混入されるとＳｉとＣが反応して不純物であるＳｉＣが生成するおそれがある。ＳｉＣが生成すると、Ｓｉが消費されて、Ｓｉ粒子の量が減るおそれがある。また、１７００Ｋ（約１４２７℃）以下であれば、ＳｉＣが生成しにくいため、反応場が１７００Ｋ（約１４２７℃）以下の雰囲気となるように、炭素源ガスが通過流に向かって噴射されることが望ましい。例えば、プラズマ出力の調整、炭素源ガスの噴射位置の調整などを行なうことで、反応場の温度雰囲気を調整できる。 When producing a coated Si particle combination, in the cooling step, cooling is performed with a cooling gas flow containing a carbon source gas, and Si in the passing flow is brought into contact with the carbon source gas to form a carbon-containing coating on Si. When the cooling gas flow containing the carbon source gas is injected toward the passing flow, it is preferable that the carbon source gas is not mixed into the plasma. If the carbon source gas is mixed in the plasma, Si and C may react to generate SiC as an impurity. When SiC is generated, Si is consumed, and the amount of Si particles may be reduced. Moreover, since it is difficult to generate SiC at 1700 K (about 1427 ° C.) or less, the carbon source gas is injected toward the passing flow so that the reaction field becomes an atmosphere of 1700 K (about 1427 ° C.) or less. Is desirable. For example, the temperature atmosphere of the reaction field can be adjusted by adjusting the plasma output and the injection position of the carbon source gas.
　炭素源ガスとしては、例えば、メタン、エタン、プロパン、ブタン、ペンタン、ヘキサン、ヘプタン、オクタン等のアルカン類、アセチレン、メチルアセチレン、ブチン、ペンチン、へキチン、ヘプチン、オクチン等のアルキン類、エチレン、プロピレン、ブテン、ペンテン、ヘキテン、ヘプテン、オクテン等のアルケン類、ジメチルエーテル、エチルメチルエーテル、ジエチルエーテル、エチルプロピルエーテル、ジプロピルエーテル、プロピルブチルエーテル、ジブチルエーテル等のエーテル類、エチレングリコール、プロピレングリコール、グリセリン等のグリコール類、ギ酸メチル、ギ酸エチル、酢酸エチル、酢酸メチル、酪酸メチル、酪酸エチル等のエステル類、ジエチルエーテル、エチルメチルエーテル、テトラヒドロフラン等位のエーテル類、フルオロメタン、ジクロロフルオロメタン、フルオロエタン、テトラフルオロエタン、ジフルオロエタン、フルオロ酢酸、フルオロスルホン酸、クロロジフルオロメタン等のフルオロカーボン類、ベンゼン、トルエン、キシレン、ピリジン、フラン等の芳香族類が挙げられる。これらは単独で用いてもよいし、複数種を併用してもよい。炭素源ガスとしては、アルカン類、アルキン類、アルケン類が好ましい。 Examples of the carbon source gas include alkanes such as methane, ethane, propane, butane, pentane, hexane, heptane, and octane, alkynes such as acetylene, methylacetylene, butyne, pentyne, hexyne, heptine, and octyne, ethylene, Alkenes such as propylene, butene, pentene, hexene, heptene, octene, ethers such as dimethyl ether, ethyl methyl ether, diethyl ether, ethyl propyl ether, dipropyl ether, propyl butyl ether, dibutyl ether, ethylene glycol, propylene glycol, glycerin Glycols such as methyl formate, ethyl formate, ethyl acetate, methyl acetate, methyl butyrate, ethyl butyrate, diethyl ether, ethyl methyl ether, tetrahydrofuran Ethers, fluoromethane, dichlorofluoromethane, fluoroethane, tetrafluoroethane, difluoroethane, fluorocarbons such as fluoroacetic acid, fluorosulfonic acid, chlorodifluoromethane, and aromatics such as benzene, toluene, xylene, pyridine, and furan Is mentioned. These may be used alone or in combination of two or more. As the carbon source gas, alkanes, alkynes, and alkenes are preferable.
　被膜付きＳｉ粒子結合体を製造する場合は、冷却ガスとして炭素源ガスのみを用いてもよいし、炭素源ガスと希ガスとを併用してもよい。冷却ガスにおける炭素源ガスの割合は、希ガス：炭素源ガス＝０：１００～９９．５：０．５が好ましく、希ガス：炭素源ガス＝８０：２０～９９：１がより好ましく、希ガス：炭素源ガス＝８５：１５～９８．５：１．５がさらに好ましい。炭素源ガスの流量としては、例えば０．１Ｌ／ｍｉｎ．～１０Ｌ／ｍｉｎ．の範囲内を例示でき、０．１Ｌ／ｍｉｎ．以上５Ｌ／ｍｉｎ．以下であることが好ましく、０．１Ｌ／ｍｉｎ．以上３Ｌ／ｍｉｎ．以下であることがより好ましい。 When producing a coated Si particle combination, only a carbon source gas may be used as a cooling gas, or a carbon source gas and a rare gas may be used in combination. The ratio of the carbon source gas in the cooling gas is preferably noble gas: carbon source gas = 0: 100 to 99.5: 0.5, more preferably noble gas: carbon source gas = 80: 20 to 99: 1. Gas: carbon source gas = 85: 15 to 98.5: 1.5 is more preferable. The flow rate of the carbon source gas is, for example, 0.1 L / min. ~ 10L / min. Within the range of 0.1 L / min. 5 L / min. Or less, preferably 0.1 L / min. 3 L / min. The following is more preferable.
　被膜付きＳｉ粒子結合体を製造する場合は、単位時間あたりの原料Ｓｉ粉末の供給モル数に対する単位時間当たりの炭素源ガスの供給モル数を調節することで、被膜の構造を調整することができる。例えば、単位時間あたりの原料Ｓｉ粉末の供給モル数に対する単位時間あたりの炭素源ガスの供給モル数の比であるＣ／Ｓｉを１．５以下とすることでＳｉＣの生成を抑制することができる。また、Ｃ／Ｓｉを０．５以上とすれば、容易に炭素含有被膜をＳｉ粒子結合体の表面に製造できる。Ｃ／Ｓｉが大きすぎると、ＳｉＣが発生しやすくなり、Ｃ／Ｓｉが小さすぎると炭素含有被膜がＳｉ粒子結合体の表面に形成しにくくなる。 When producing a coated Si particle combination, the coating structure can be adjusted by adjusting the number of moles of carbon source gas supplied per unit time relative to the number of moles of raw material Si powder supplied per unit time. . For example, the production of SiC can be suppressed by setting C / Si, which is the ratio of the number of moles of carbon source gas supplied per unit time to the number of moles of raw material Si powder supplied per unit time, to 1.5 or less. . If C / Si is 0.5 or more, a carbon-containing coating can be easily produced on the surface of the Si particle combination. When C / Si is too large, SiC is likely to be generated, and when C / Si is too small, it becomes difficult to form a carbon-containing coating on the surface of the Si particle combination.
　被膜付きＳｉ粒子結合体を製造する場合は、冷却工程後に、冷却工程にて形成された炭素含有被膜付きＳｉ粒子結合体を酸素含有雰囲気下に保持し、炭素含有被膜に酸素を導入する酸素導入工程を有してもよい。冷却工程において、反応場の温度が低い場合又は反応時間が短い場合は、炭素源ガスに含まれるＨがすべて解離せずに、Ｓｉ粒子結合体の表面には、ラジカル状態のＣＨが存在することが推測される。そのため、冷却工程後に、ラジカル状態のＣＨを有する炭素含有被膜を酸素含有雰囲気下におくと、ラジカル状態のＣＨに酸素が結合し、炭素含有被膜に容易に酸素が導入される。また、酸素とラジカル状態のＣＨが接触することによって、Ｓｉ粒子結合体の表面は安定すると考えられる。つまり、酸素導入工程は、被膜付きＳｉ粒子結合体の安定化工程とも言える。 In the case of producing a coated Si particle bonded body, after the cooling step, the carbon particle-containing Si particle bonded body formed in the cooling step is maintained in an oxygen-containing atmosphere, and oxygen is introduced into the carbon-containing coated film. You may have a process. In the cooling step, when the temperature of the reaction field is low or the reaction time is short, all of the H contained in the carbon source gas is not dissociated and CH in the radical state exists on the surface of the Si particle bonded body. Is guessed. Therefore, when the carbon-containing film having CH in the radical state is placed in an oxygen-containing atmosphere after the cooling step, oxygen is bonded to the CH in the radical state, and oxygen is easily introduced into the carbon-containing film. Further, it is considered that the surface of the Si particle bonded body is stabilized by contact of oxygen and radical state CH. That is, it can be said that the oxygen introduction step is a stabilization step of the coated Si particle combination.
　本発明の被膜付きＳｉ粒子結合体の他の製造方法は、原料Ｓｉ粉末を導入流にてプラズマ内に導入する工程と、導入流がプラズマ内を通過した後の通過流を通過流に対向する炭素源ガスを含む冷却ガス流で冷却し、通過流内のＳｉを炭素源ガスと接触させてＳｉに炭素含有被膜を形成させる冷却工程と、を含み、冷却工程において、冷却ガス流は、炭素源ガス及び希ガスを含み、炭素源ガスの供給位置は、希ガスの供給位置よりも、通過流の通過方向に対して下流であることを特徴とする。 In another method for producing a coated Si particle assembly according to the present invention, a raw material Si powder is introduced into a plasma by an introduction flow, and a passing flow after the introduction flow passes through the plasma is opposed to the passing flow. Cooling with a cooling gas stream containing a carbon source gas, and contacting Si in the passing stream with the carbon source gas to form a carbon-containing film on the Si, wherein the cooling gas stream is carbon The supply position of the carbon source gas includes the source gas and the rare gas, and is characterized in that the supply position of the carbon source gas is downstream with respect to the passage direction of the passing flow.
　冷却ガスを通過流に対向させて噴射する場合、希ガスを供給する開口部と、炭素源ガスを供給する開口部とを別にし、炭素源ガスを供給する開口部の位置を、希ガスを供給する開口部の位置よりも通過流の通過方向に対して下流である位置に設定すればよい。実施例で用いたプラズマ発生装置の場合、希ガス供給管の開口とプラズマ発生装置内の開口との距離よりも、炭素源ガス供給管の開口とプラズマ発生装置内の開口との距離を５０ｍｍ以上大きくするのが好ましい。 In the case of injecting the cooling gas so as to oppose the passing flow, the opening for supplying the rare gas and the opening for supplying the carbon source gas are separated, and the position of the opening for supplying the carbon source gas is changed to the position of the rare gas. What is necessary is just to set to the position which is downstream with respect to the passage direction of a passage flow rather than the position of the opening part to supply. In the case of the plasma generator used in the examples, the distance between the opening of the carbon source gas supply pipe and the opening in the plasma generator is 50 mm or more than the distance between the opening of the rare gas supply pipe and the opening in the plasma generator. It is preferable to enlarge it.
　被膜付きＳｉ粒子結合体を製造するには、プラズマ出力、原料Ｓｉ粉末の供給速度、炭素源ガスの流速及び炭素源ガスの供給位置を適宜調整する。例えば、プラズマ出力の大きさに合わせて、原料Ｓｉ粉末の供給速度、炭素源ガスの流速及び炭素源ガスの供給位置を調整すればよい。プラズマ出力を大きくすれば、プラズマ内の温度を大きく低下することなく、原料Ｓｉ粉末の供給速度を大きくできる。プラズマ出力を大きくする場合は、炭素源ガスの供給位置を希ガスの供給位置よりも、通過流の通過方向に対してさらに下流にすればよい。炭素源ガスの供給位置を通過流の通過方向に対してさらに下流にすることによって、原料Ｓｉ粉末の供給速度を大きくしても、不純物であるＳｉＣの生成を抑制できる。 In order to produce a coated Si particle assembly, the plasma output, the feed rate of the raw material Si powder, the flow rate of the carbon source gas, and the supply position of the carbon source gas are appropriately adjusted. For example, the supply rate of the raw material Si powder, the flow rate of the carbon source gas, and the supply position of the carbon source gas may be adjusted in accordance with the magnitude of the plasma output. If the plasma output is increased, the feed rate of the raw material Si powder can be increased without greatly reducing the temperature in the plasma. In order to increase the plasma output, the supply position of the carbon source gas may be further downstream than the supply position of the rare gas with respect to the passing direction of the passing flow. By making the supply position of the carbon source gas further downstream with respect to the passing direction of the passing flow, the generation of SiC as an impurity can be suppressed even if the supply speed of the raw material Si powder is increased.
　プラズマ出力は３ｋＷ～３００ｋＷが好ましく、５ｋＷ～１００ｋＷがより好ましく、５ｋＷ～２０ｋＷがさらに好ましい。 The plasma output is preferably 3 kW to 300 kW, more preferably 5 kW to 100 kW, and even more preferably 5 kW to 20 kW.
　プラズマ出力当たりの原料Ｓｉ粉末の供給速度は、０．０１ｇ／ｍｉｎ．／ｋＷ～１ｇ／ｍｉｎ．／ｋＷが好ましく、０．０１ｇ／ｍｉｎ．／ｋＷ～０．５ｇ／ｍｉｎ．／ｋＷがより好ましく、０．０１ｇ／ｍｉｎ．／ｋＷ～０．１ｇ／ｍｉｎ．／ｋＷがさらに好ましい。 The supply rate of the raw material Si powder per plasma output is 0.01 g / min. / KW to 1 g / min. / KW is preferred, and 0.01 g / min. / KW to 0.5 g / min. / KW is more preferable, 0.01 g / min. / KW to 0.1 g / min. / KW is more preferable.
　炭素源ガスの供給位置は、希ガスの供給位置よりも、通過流の通過方向に対して下流とする場合、単位時間あたりの原料Ｓｉ粉末の供給モル数に対する単位時間あたりの炭素源ガスの供給モル数の比であるＣ／Ｓｉを１．５以上としても、ＳｉＣの生成を抑制することができる。 When the supply position of the carbon source gas is downstream from the supply position of the rare gas with respect to the passing direction of the passing flow, the supply of the carbon source gas per unit time with respect to the supply mole number of the raw material Si powder per unit time Even if C / Si, which is the mole ratio, is 1.5 or more, the generation of SiC can be suppressed.
　本発明のＳｉ粒子結合体又は被膜付きＳｉ粒子結合体は、リチウムイオン二次電池などの非水電解質二次電池の負極活物質として使用することができる。本発明のＳｉ粒子結合体又は被膜付きＳｉ粒子結合体を含む負極活物質を本発明の負極活物質と呼ぶ。 The Si particle bonded body or coated Si particle bonded body of the present invention can be used as a negative electrode active material for a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. The negative electrode active material containing the Si particle combination or the coated Si particle combination of the present invention is referred to as the negative electrode active material of the present invention.
　また、本発明の負極活物質から派生した本発明の第２負極活物質として、以下の発明を把握できる。 Further, the following invention can be grasped as the second negative electrode active material of the present invention derived from the negative electrode active material of the present invention.
　本発明の第２負極活物質は、Ｓｉ粒子と、該Ｓｉ粒子の表面に配置され、Ｃ、Ｈ、Ｏを含む炭素含有被膜と、を有し、該炭素含有被膜は、熱分解ガスクロマトグラフ質量分析において、テルペン類のフラグメントが検出されることを特徴とする。 The second negative electrode active material of the present invention has Si particles and a carbon-containing film that is disposed on the surface of the Si particles and contains C, H, and O. The carbon-containing film has a pyrolysis gas chromatograph mass. The analysis is characterized in that fragments of terpenes are detected.
　Ｓｉ粒子は、上記プラズマ発生装置を用いて製造されたものであれば、いかなる形状のものでもかまわない。 The Si particles may be of any shape as long as they are manufactured using the plasma generator.
　本発明の第２負極活物質に関するその他の事項は、本発明の負極活物質の説明を援用する。以下、本発明の負極活物質又は第２負極活物質を具備する負極を本発明の負極と呼び、本発明の負極を具備する非水電解質二次電池を本発明の非水電解質二次電池と呼ぶ。リチウムイオン二次電池を例にして、本発明の非水電解質二次電池を説明する。 For other matters related to the second negative electrode active material of the present invention, the description of the negative electrode active material of the present invention is incorporated. Hereinafter, the negative electrode including the negative electrode active material or the second negative electrode active material of the present invention is referred to as the negative electrode of the present invention, and the nonaqueous electrolyte secondary battery including the negative electrode of the present invention is referred to as the nonaqueous electrolyte secondary battery of the present invention. Call. The non-aqueous electrolyte secondary battery of the present invention will be described using a lithium ion secondary battery as an example.
（リチウムイオン二次電池）
　本発明のリチウムイオン二次電池における負極は、集電体と、集電体の表面に結着された負極活物質層とを有する。 (Lithium ion secondary battery)
The negative electrode in the lithium ion secondary battery of the present invention has a current collector and a negative electrode active material layer bound to the surface of the current collector.
　負極活物質としては、既述したとおり、本発明の負極活物質又は本発明の第２負極活物質を用いる。本発明のリチウムイオン二次電池における負極活物質層は、本発明の負極活物質又は本発明の第２負極活物質以外にも、他の公知の負極活物質、結着剤、導電助剤、その他の添加剤を含有し得る。 As described above, the negative electrode active material of the present invention or the second negative electrode active material of the present invention is used as the negative electrode active material. In addition to the negative electrode active material of the present invention or the second negative electrode active material of the present invention, the negative electrode active material layer in the lithium ion secondary battery of the present invention includes other known negative electrode active materials, binders, conductive assistants, Other additives may be included.
　他の公知の負極活物質としては、リチウムを吸蔵及び放出可能な炭素系材料、リチウムと合金化可能な元素、リチウムと合金化可能な元素を有する化合物、あるいは高分子材料などを例示することができる。他の公知の負極活物質としては、炭素系材料が好ましい。 Examples of other known negative electrode active materials include carbon-based materials capable of inserting and extracting lithium, elements capable of being alloyed with lithium, compounds having elements capable of being alloyed with lithium, and polymer materials. it can. As other known negative electrode active materials, carbon-based materials are preferable.
　炭素系材料としては、難黒鉛化性炭素、黒鉛、コークス類、グラファイト類、ガラス状炭素類、有機高分子化合物焼成体、炭素繊維、活性炭あるいはカーボンブラック類が例示できる。ここで、有機高分子化合物焼成体とは、フェノール類やフラン類などの高分子材料を適当な温度で焼成して炭素化したものをいう。 Examples of the carbon-based material include non-graphitizable carbon, graphite, coke, graphite, glassy carbon, organic polymer compound fired body, carbon fiber, activated carbon, or carbon black. Here, the organic polymer compound fired body refers to a material obtained by firing and carbonizing a polymer material such as phenols and furans at an appropriate temperature.
　リチウムと合金化可能な元素としては、具体的にＮａ、Ｋ、Ｒｂ、Ｃｓ、Ｆｒ、Ｂｅ、Ｍｇ、Ｃａ、Ｓｒ、Ｂａ、Ｒａ、Ｔｉ、Ａｇ、Ｚｎ、Ｃｄ、Ａｌ、Ｇａ、Ｉｎ、Ｓｉ、Ｇｅ、Ｓｎ、Ｐｂ、Ｓｂ、Ｂｉが例示できる。 Specifically, elements that can be alloyed with lithium include Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Ti, Ag, Zn, Cd, Al, Ga, In, Si. , Ge, Sn, Pb, Sb, and Bi.
　リチウムと合金化可能な元素を有する化合物としては、具体的にＺｎＬｉＡｌ、ＡｌＳｂ、ＳｉＢ４、ＳｉＢ６、Ｍｇ２Ｓｉ、Ｍｇ２Ｓｎ、Ｎｉ２Ｓｉ、ＴｉＳｉ２、ＭｏＳｉ２、 ＣｏＳｉ２、ＮｉＳｉ２、ＣａＳｉ２、ＣｒＳｉ２、Ｃｕ５Ｓｉ、ＦｅＳｉ２、ＭｎＳｉ２、ＮｂＳｉ２、ＴａＳｉ２、ＶＳｉ２、ＷＳｉ２、ＺｎＳｉ２、ＳｉＣ、Ｓｉ３Ｎ４、Ｓｉ２Ｎ２Ｏ、ＳｉＯｖ（０＜ｖ≦２）、ＳｎＯｗ（０＜ｗ≦２）、ＳｎＳｉＯ３、ＬｉＳｉＯ あるいはＬｉＳｎＯを例示できる。 Specific examples of compounds having elements that can be alloyed with lithium include ZnLiAl, AlSb, SiB 4 , SiB 6 , Mg 2 Si, Mg 2 Sn, Ni 2 Si, TiSi 2 , MoSi 2 , CoSi 2 , NiSi 2 , CaSi 2, CrSi 2, Cu 5 Si, FeSi 2, MnSi 2, NbSi 2, TaSi 2, VSi 2, WSi 2, ZnSi 2, SiC, Si 3 N 4, Si 2 N 2 O, SiO v (0 <v ≦ 2), SnO w (0 <w ≦ 2), SnSiO 3 , LiSiO 2 or LiSnO.
　高分子材料としては、具体的にポリアセチレン、ポリピロールを例示できる。 Specific examples of the polymer material include polyacetylene and polypyrrole.
　負極活物質層全体を１００質量％としたときの負極活物質の量は、百分率で、６０質量％～９９質量％の範囲内が好ましく、６５質量％～９８質量％の範囲内がより好ましく、７０質量％～９７質量％の範囲内が特に好ましい。 The amount of the negative electrode active material when the total amount of the negative electrode active material layer is 100% by mass is preferably in the range of 60% by mass to 99% by mass, more preferably in the range of 65% by mass to 98% by mass, A range of 70% by mass to 97% by mass is particularly preferable.
　結着剤は、負極活物質や導電助剤を集電体の表面に繋ぎ止める役割を果たすものである。結着剤としては、ポリフッ化ビニリデン、ポリテトラフルオロエチレン、フッ素ゴム等の含フッ素樹脂、ポリプロピレン、ポリエチレン等の熱可塑性樹脂、ポリイミド、ポリアミドイミド等のイミド系樹脂、アルコキシシリル基含有樹脂、スチレンブタジエンゴムを例示することができる。また、結着剤として、親水基を有するポリマーを採用してもよい。親水基を有するポリマーの親水基としては、カルボキシル基、スルホ基、シラノール基、アミノ基、水酸基、リン酸基が例示される。親水基を有するポリマーの具体例として、ポリアクリル酸、カルボキシメチルセルロース、ポリメタクリル酸などの分子中にカルボキシル基を含むポリマー、又は、ポリ（ｐ－スチレンスルホン酸）などのスルホ基を含むポリマーが挙げられる。 The binder serves to bind the negative electrode active material and the conductive auxiliary agent to the surface of the current collector. Binders include fluorine-containing resins such as polyvinylidene fluoride, polytetrafluoroethylene, and fluororubber, thermoplastic resins such as polypropylene and polyethylene, imide resins such as polyimide and polyamideimide, alkoxysilyl group-containing resins, and styrene butadiene. Rubber can be exemplified. Moreover, you may employ | adopt the polymer which has a hydrophilic group as a binder. Examples of the hydrophilic group of the polymer having a hydrophilic group include a carboxyl group, a sulfo group, a silanol group, an amino group, a hydroxyl group, and a phosphate group. Specific examples of the polymer having a hydrophilic group include a polymer containing a carboxyl group in a molecule such as polyacrylic acid, carboxymethylcellulose, and polymethacrylic acid, or a polymer containing a sulfo group such as poly (p-styrenesulfonic acid). It is done.
　また、国際公開第２０１６／０６３８８２号に開示される、ポリアクリル酸やポリメタクリル酸などのカルボキシル基含有ポリマーをジアミンなどのポリアミンで架橋した架橋ポリマーを、結着剤として用いてもよい。 Further, a crosslinked polymer obtained by crosslinking a carboxyl group-containing polymer such as polyacrylic acid or polymethacrylic acid with a polyamine such as diamine disclosed in International Publication No. 2016/063882 may be used as a binder.
　架橋ポリマーに用いられるジアミンとしては、エチレンジアミン、プロピレンジアミン、ヘキサメチレンジアミン等のアルキレンジアミン、１，４－ジアミノシクロヘキサン、１，３－ジアミノシクロヘキサン、イソホロンジアミン、ビス（４－アミノシクロヘキシル）メタン等の含飽和炭素環ジアミン、ｍ－フェニレンジアミン、ｐ－フェニレンジアミン、４，４’－ジアミノジフェニルメタン、４，４’－ジアミノジフェニルエーテル、ビス（４－アミノフェニル）スルホン、ベンジジン、ｏ－トリジン、２，４－トリレンジアミン、２，６－トリレンジアミン、キシリレンジアミン、ナフタレンジアミン等の芳香族ジアミンが挙げられる。 Diamines used in the crosslinked polymer include alkylene diamines such as ethylene diamine, propylene diamine, and hexamethylene diamine, 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, isophorone diamine, bis (4-aminocyclohexyl) methane, and the like. Saturated carbocyclic diamine, m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, bis (4-aminophenyl) sulfone, benzidine, o-tolidine, 2,4- Aromatic diamines such as tolylenediamine, 2,6-tolylenediamine, xylylenediamine, and naphthalenediamine are exemplified.
　結着剤の配合量は特に限定されないが、あえて負極活物質層における結着剤の配合量を挙げると、０．５質量％～１０質量％の範囲内が好ましく、１質量％～７質量％の範囲内がより好ましく、２質量％～５質量％の範囲内が特に好ましい。結着剤の配合量が少なすぎると負極活物質層の成形性が低下するおそれがある。また、結着剤の配合量が多すぎると、負極活物質層における負極活物質の量が相対的に減少するため、好ましくない。 The blending amount of the binder is not particularly limited. However, when the blending amount of the binder in the negative electrode active material layer is given, it is preferably in the range of 0.5% by mass to 10% by mass, and 1% by mass to 7% by mass. Is more preferable, and the range of 2% by mass to 5% by mass is particularly preferable. If the blending amount of the binder is too small, the moldability of the negative electrode active material layer may be lowered. Moreover, when there are too many compounding quantities of a binder, since the quantity of the negative electrode active material in a negative electrode active material layer reduces relatively, it is unpreferable.
　導電助剤は化学的に不活性な電子高伝導体であれば良く、炭素質微粒子であるカーボンブラック、黒鉛、気相法炭素繊維（Vapor Grown Carbon Fiber）、及び各種金属粒子等が例示される。カーボンブラックとしては、アセチレンブラック、ケッチェンブラック（登録商標）、ファーネスブラック、チャンネルブラック等が例示される。これらの導電助剤を単独または二種以上組み合わせて負極活物質層に添加することができる。 The conductive auxiliary agent may be any chemically inert electronic high conductor, such as carbon black, graphite, vapor grown carbon fiber (Vapor Grown Carbon Fiber), and various metal particles. . Examples of the carbon black include acetylene black, ketjen black (registered trademark), furnace black, and channel black. These conductive assistants can be added to the negative electrode active material layer alone or in combination of two or more.
　導電助剤の形状は特に制限されないが、その役割からみて、導電助剤の平均粒径は小さいほうが好ましい。導電助剤の好ましい平均粒径として１０μｍ以下が例示され、より好ましい平均粒径として０．０１μｍ～１μｍの範囲が例示される。 The shape of the conductive auxiliary agent is not particularly limited, but it is preferable that the average particle size of the conductive auxiliary agent is small in view of its role. A preferable average particle size of the conductive assistant is 10 μm or less, and a more preferable average particle size is in the range of 0.01 μm to 1 μm.
　導電助剤の配合量は特に限定されないが、あえて負極活物質層における導電助剤の配合量を挙げると、０．５質量％～１０質量％の範囲内がよく、１質量％～７質量％の範囲内が好ましく、２質量％～５質量％の範囲内が特に好ましい。 The blending amount of the conductive assistant is not particularly limited, but if the blending amount of the conductive assistant in the negative electrode active material layer is given, it is preferably in the range of 0.5% by mass to 10% by mass, and 1% by mass to 7% by mass. Is preferably within the range of 2% by mass to 5% by mass.
　導電助剤及び結着剤以外の分散剤などの添加剤は、公知のものを採用することができる。 Known additives can be used as additives such as a dispersant other than the conductive auxiliary agent and the binder.
　集電体は、リチウムイオン二次電池の放電又は充電の間、電極に電流を流し続けるための化学的に不活性な電子高伝導体をいう。集電体としては、銀、銅、金、アルミニウム、タングステン、コバルト、亜鉛、ニッケル、鉄、白金、錫、インジウム、チタン、ルテニウム、タンタル、クロム、モリブデンから選ばれる少なくとも一種、並びにステンレス鋼などの金属材料を例示することができる。集電体は公知の保護層で被覆されていてもよい。集電体の表面を公知の方法で処理したものを集電体として用いてもよい。 A current collector refers to a chemically inert electronic high conductor that keeps a current flowing through an electrode during discharge or charging of a lithium ion secondary battery. As the current collector, at least one selected from silver, copper, gold, aluminum, tungsten, cobalt, zinc, nickel, iron, platinum, tin, indium, titanium, ruthenium, tantalum, chromium, molybdenum, and stainless steel, etc. Metal materials can be exemplified. The current collector may be covered with a known protective layer. What collected the surface of the electrical power collector by the well-known method may be used as an electrical power collector.
　集電体は箔、シート、フィルム、線状、棒状、メッシュなどの形態をとることができる。そのため、集電体として、例えば、銅箔、ニッケル箔、アルミニウム箔、ステンレス箔などの金属箔を好適に用いることができる。集電体が箔、シート、フィルム形態の場合は、その厚みが１μｍ～１００μｍの範囲内であることが好ましい。 The current collector can take the form of a foil, a sheet, a film, a linear shape, a rod shape, a mesh, or the like. Therefore, for example, a metal foil such as a copper foil, a nickel foil, an aluminum foil, and a stainless steel foil can be suitably used as the current collector. When the current collector is in the form of foil, sheet or film, the thickness is preferably in the range of 1 μm to 100 μm.
　集電体の表面に負極活物質層を結着させるには、ロールコート法、ダイコート法、ディップコート法、ドクターブレード法、スプレーコート法、カーテンコート法などの従来から公知の方法を用いて、集電体の表面に負極活物質を塗布すればよい。具体的には、活物質、溶剤、並びに必要に応じて結着剤及び導電助剤を混合してスラリーにしてから、当該スラリーを集電体の表面に塗布後、乾燥する。溶剤としては、Ｎ－メチル－２－ピロリドン、メタノール、メチルイソブチルケトン、水を例示できる。電極密度を高めるべく、乾燥後のものを圧縮してもよい。 In order to bind the negative electrode active material layer to the surface of the current collector, a conventionally known method such as a roll coating method, a die coating method, a dip coating method, a doctor blade method, a spray coating method, or a curtain coating method is used. A negative electrode active material may be applied to the surface of the current collector. Specifically, an active material, a solvent, and if necessary, a binder and a conductive additive are mixed to form a slurry, and the slurry is applied to the surface of the current collector and then dried. Examples of the solvent include N-methyl-2-pyrrolidone, methanol, methyl isobutyl ketone, and water. In order to increase the electrode density, the dried product may be compressed.
　本発明のリチウムイオン二次電池の一態様として、本発明の負極、正極、電解液及びセパレータを具備するものが挙げられる。 Examples of one aspect of the lithium ion secondary battery of the present invention include those equipped with the negative electrode, positive electrode, electrolytic solution, and separator of the present invention.
　正極は、集電体と、集電体上に結着された正極活物質層とを有する。正極活物質層は、正極活物質と、結着剤とを含み、さらには導電助剤及びその他の添加剤を含んでもよい。正極活物質、導電助剤及び結着剤は、特に限定はない。 The positive electrode has a current collector and a positive electrode active material layer bound on the current collector. The positive electrode active material layer includes a positive electrode active material and a binder, and may further include a conductive additive and other additives. A positive electrode active material, a conductive support agent, and a binder are not particularly limited.
　正極活物質としては、Ｌｉ等の電荷担体を吸蔵及び放出可能なものを使用すればよい。正極活物質としては、層状化合物のＬｉａＮｉｂＣｏｃＭｎｄＤｅＯｆ(０．２≦ａ≦２、ｂ＋ｃ＋ｄ＋ｅ＝１、０≦ｅ＜１、ＤはＬｉ、Ｆｅ、Ｃｒ、Ｃｕ、Ｚｎ、Ｃａ、Ｍｇ、Ｓ、Ｓｉ、Ｎａ、Ｋ、Ａｌ、Ｚｒ、Ｔｉ、Ｐ、Ｇａ、Ｇｅ、Ｖ、Ｍｏ、Ｎｂ、Ｗ、Ｌａから選ばれる少なくとも１の元素、１．７≦ｆ≦３)、Ｌｉ２ＭｎＯ３を挙げることができる。また、正極活物質として、ＬｉＭｎ２Ｏ４、Ｌｉ２Ｍｎ２Ｏ４等のスピネル、及びスピネルと層状化合物の混合物で構成される固溶体、ＬｉＭＰＯ４、ＬｉＭＶＯ４又はＬｉ２ＭＳｉＯ４（式中のＭはＣｏ、Ｎｉ、Ｍｎ、Ｆｅのうちの少なくとも一種から選択される）などで表されるポリアニオン系化合物を挙げることができる。さらに、正極活物質として、ＬｉＦｅＰＯ４ＦなどのＬｉＭＰＯ４Ｆ（Ｍは遷移金属）で表されるタボライト系化合物、ＬｉＦｅＢＯ３などのＬｉＭＢＯ３（Ｍは遷移金属）で表されるボレート系化合物を挙げることができる。正極活物質として用いられるいずれの金属酸化物も上記の組成式を基本組成とすればよく、基本組成に含まれる金属元素を他の金属元素で置換したものも使用可能である。また、正極活物質として、充放電に寄与するリチウムイオンを含まない正極活物質材料、たとえば、硫黄単体（Ｓ）、硫黄と炭素を複合化した化合物、ＴｉＳ２などの金属硫化物、Ｖ２Ｏ５、ＭｎＯ２などの酸化物、ポリアニリン及びアントラキノン並びにこれら芳香族を化学構造に含む化合物、共役二酢酸系有機物などの共役系材料、その他公知の材料を用いることもできる。さらに、ニトロキシド、ニトロニルニトロキシド、ガルビノキシル、フェノキシルなどの安定なラジカルを有する化合物を正極活物質として採用してもよい。リチウムを含まない正極活物質材料を用いる場合には、正極及び／又は負極に、公知の方法により、予めイオンを添加させておく必要がある。ここで、当該イオンを添加するためには、金属又は当該イオンを含む化合物を用いればよい。 As the positive electrode active material, a material capable of occluding and releasing charge carriers such as Li may be used. As the positive electrode active material, the layered compound Li a Ni b Co c Mn d De O f (0.2 ≦ a ≦ 2, b + c + d + e = 1, 0 ≦ e <1, D is Li, Fe, Cr, Cu, At least one element selected from Zn, Ca, Mg, S, Si, Na, K, Al, Zr, Ti, P, Ga, Ge, V, Mo, Nb, W, La, 1.7 ≦ f ≦ 3 ), Li 2 MnO 3 . Further, as a positive electrode active material, a solid solution composed of a spinel such as LiMn 2 O 4 and Li 2 Mn 2 O 4 and a mixture of a spinel and a layered compound, LiMPO 4 , LiMVO 4, or Li 2 MSiO 4 (M in the formula) Are selected from at least one of Co, Ni, Mn, and Fe). Furthermore, as the positive electrode active material, tavorite compound (the M a transition metal) LiMPO 4 F, such as LiFePO 4 F represented by, Limbo 3 such LiFeBO 3 (M is a transition metal) include borate-based compound represented by be able to. Any metal oxide used as the positive electrode active material may have the above composition formula as a basic composition, and a metal element contained in the basic composition may be substituted with another metal element. Further, as the positive electrode active material, a positive electrode active material that does not contain lithium ions contributing to charge / discharge, for example, sulfur alone (S), a compound in which sulfur and carbon are combined, a metal sulfide such as TiS 2 , V 2 O, etc. 5 , oxides such as MnO 2 , polyaniline and anthraquinone, compounds containing these aromatics in the chemical structure, conjugated materials such as conjugated diacetic acid organic materials, and other known materials can also be used. Further, a compound having a stable radical such as nitroxide, nitronyl nitroxide, galvinoxyl, phenoxyl, etc. may be adopted as the positive electrode active material. When using a positive electrode active material that does not contain lithium, it is necessary to add ions to the positive electrode and / or the negative electrode in advance by a known method. Here, in order to add the ion, a metal or a compound containing the ion may be used.
　正極に用いる集電体は、アルミニウム、ニッケル、ステンレス鋼など、リチウムイオン二次電池の正極に一般的に使用されるものであればよく、それ以外は負極で説明した集電体と同様である。 The current collector used for the positive electrode is not limited as long as it is generally used for the positive electrode of a lithium ion secondary battery, such as aluminum, nickel, and stainless steel. .
　正極に用いる導電助剤については、負極で説明したものを同様の配合割合で適宜適切に採用すればよい。正極に用いる結着剤については、負極で説明したものを同様の配合割合で適宜適切に採用すればよい。 What is necessary is just to employ | adopt suitably suitably what was demonstrated with the negative electrode about the conductive support agent used for a positive electrode with the same mixture ratio. What is necessary is just to employ | adopt suitably suitably about the binder used for a positive electrode by the same mixture ratio as what was demonstrated with the negative electrode.
　電解液は、非水溶媒と非水溶媒に溶解した電解質とを含んでいる。 The electrolytic solution contains a non-aqueous solvent and an electrolyte dissolved in the non-aqueous solvent.
　非水溶媒としては、環状エステル類、鎖状エステル類、エーテル類等が使用できる。環状エステル類としては、エチレンカーボネート、プロピレンカーボネート、ブチレンカーボネート、ガンマブチロラクトン、ビニレンカーボネート、２－メチル－ガンマブチロラクトン、アセチル－ガンマブチロラクトン、ガンマバレロラクトンを例示できる。鎖状エステル類としては、ジメチルカーボネート、ジエチルカーボネート、ジブチルカーボネート、ジプロピルカーボネート、エチルメチルカーボネート、プロピオン酸アルキルエステル、マロン酸ジアルキルエステル、酢酸アルキルエステル等を例示できる。エーテル類としては、テトラヒドロフラン、２－メチルテトラヒドロフラン、１，４－ジオキサン、１，２－ジメトキシエタン、１，２－ジエトキシエタン、１，２－ジブトキシエタンを例示できる。非水溶媒としては、上記具体的な溶媒の化学構造のうち一部又は全部の水素がフッ素に置換した化合物を採用してもよい。 As the non-aqueous solvent, cyclic esters, chain esters, ethers and the like can be used. Examples of cyclic esters include ethylene carbonate, propylene carbonate, butylene carbonate, gamma butyrolactone, vinylene carbonate, 2-methyl-gamma butyrolactone, acetyl-gamma butyrolactone, and gamma valerolactone. Examples of chain esters include dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dipropyl carbonate, ethyl methyl carbonate, propionic acid alkyl ester, malonic acid dialkyl ester, and acetic acid alkyl ester. Examples of ethers include tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, and 1,2-dibutoxyethane. As the non-aqueous solvent, a compound in which a part or all of hydrogen in the chemical structure of the above specific solvent is substituted with fluorine may be employed.
　電解質としては、ＬｉＣｌＯ４、ＬｉＡｓＦ６、ＬｉＰＦ６、ＬｉＢＦ４、ＬｉＣＦ３ＳＯ３、ＬｉＮ（ＣＦ３ＳＯ２）２等のリチウム塩を例示できる。 Examples of the electrolyte include lithium salts such as LiClO 4 , LiAsF 6 , LiPF 6 , LiBF 4 , LiCF 3 SO 3 , and LiN (CF 3 SO 2 ) 2 .
　電解液としては、エチレンカーボネート、ジメチルカーボネート、プロピレンカーボネート、ジエチルカーボネートなどの非水溶媒に、ＬｉＣｌＯ４、ＬｉＰＦ６、ＬｉＢＦ４、ＬｉＣＦ３ＳＯ３などのリチウム塩を０．５ｍｏｌ／Ｌから１．７ｍｏｌ／Ｌ程度の濃度で溶解させた溶液を例示できる。 As an electrolytic solution, 0.5 mol / L to 1.7 mol of a lithium salt such as LiClO 4 , LiPF 6 , LiBF 4 , LiCF 3 SO 3 in a nonaqueous solvent such as ethylene carbonate, dimethyl carbonate, propylene carbonate, and diethyl carbonate. A solution dissolved at a concentration of about / L can be exemplified.
　セパレータは、正極と負極とを隔離し、両極の接触による短絡を防止しつつ、リチウムイオンを通過させるものである。セパレータとしては、ポリテトラフルオロエチレン、ポリプロピレン、ポリエチレン、ポリイミド、ポリアミド、ポリアラミド（Ａｒｏｍａｔｉｃ　ｐｏｌｙａｍｉｄｅ）、ポリエステル、ポリアクリロニトリル等の合成樹脂、セルロース、アミロース等の多糖類、フィブロイン、ケラチン、リグニン、スベリン等の天然高分子、セラミックスなどの電気絶縁性材料を１種若しくは複数用いた多孔体、不織布、織布などを挙げることができる。また、セパレータは多層構造としてもよい。 The separator separates the positive electrode and the negative electrode and allows lithium ions to pass while preventing a short circuit due to contact between the two electrodes. As separators, natural resins such as polytetrafluoroethylene, polypropylene, polyethylene, polyimide, polyamide, polyaramid (Aromatic polymer), polyester, polyacrylonitrile, etc., polysaccharides such as cellulose, amylose, fibroin, keratin, lignin, suberin, etc. Examples thereof include porous bodies, nonwoven fabrics, and woven fabrics using one or more electrically insulating materials such as polymers and ceramics. The separator may have a multilayer structure.
　本発明のリチウムイオン二次電池の製造方法は、本発明の負極を配設する工程を含む。具体的には、以下のとおりである。 The method for producing a lithium ion secondary battery of the present invention includes a step of disposing the negative electrode of the present invention. Specifically, it is as follows.
　正極および負極に必要に応じてセパレータを挟装させ電極体とする。電極体は、正極、セパレータ及び負極を重ねた積層型、又は、正極、セパレータ及び負極を捲いた捲回型のいずれの型にしてもよい。正極の集電体および負極の集電体から外部に通ずる正極端子および負極端子までの間を、集電用リード等を用いて接続した後に、電極体に電解液を加えてリチウムイオン二次電池とするとよい。また、本発明のリチウムイオン二次電池は、電極に含まれる活物質の種類に適した電圧範囲で充放電を実行されればよい。 A separator is sandwiched between the positive electrode and the negative electrode as necessary to form an electrode body. The electrode body may be any of a stacked type in which a positive electrode, a separator and a negative electrode are stacked, or a wound type in which a positive electrode, a separator and a negative electrode are sandwiched. After connecting between the positive electrode current collector and the negative electrode current collector to the positive electrode terminal and the negative electrode terminal connected to the outside using a current collecting lead or the like, an electrolytic solution is added to the electrode body to form a lithium ion secondary battery. It is good to do. Moreover, the lithium ion secondary battery of this invention should just be charged / discharged in the voltage range suitable for the kind of active material contained in an electrode.
　本発明のリチウムイオン二次電池の形状は特に限定されるものでなく、円筒型、角型、コイン型、ラミネート型等、種々の形状を採用することができる。 The shape of the lithium ion secondary battery of the present invention is not particularly limited, and various shapes such as a cylindrical shape, a square shape, a coin shape, and a laminate shape can be adopted.
　本発明のリチウムイオン二次電池は、車両に搭載してもよい。車両は、その動力源の全部あるいは一部に二次電池による電気エネルギーを使用している車両であればよく、たとえば、電気車両、ハイブリッド車両などであるとよい。車両にリチウムイオン二次電池を搭載する場合には、リチウムイオン二次電池を複数直列に接続して組電池とするとよい。リチウムイオン二次電池を搭載する機器としては、車両以外にも、パーソナルコンピュータ、携帯通信機器など、電池で駆動される各種の家電製品、オフィス機器、産業機器などが挙げられる。さらに、本発明のリチウムイオン二次電池は、風力発電、太陽光発電、水力発電その他電力系統の蓄電装置及び電力平滑化装置、船舶等の動力及び／又は補機類の電力供給源、航空機、宇宙船等の動力及び／又は補機類の電力供給源、電気を動力源に用いない車両の補助用電源、移動式の家庭用ロボットの電源、システムバックアップ用電源、無停電電源装置の電源、電動車両用充電ステーションなどにおいて充電に必要な電力を一時蓄える蓄電装置に用いてもよい。 The lithium ion secondary battery of the present invention may be mounted on a vehicle. The vehicle may be a vehicle that uses electric energy from the secondary battery for all or part of its power source, and may be, for example, an electric vehicle, a hybrid vehicle, or the like. When a lithium ion secondary battery is mounted on a vehicle, a plurality of lithium ion secondary batteries may be connected in series to form an assembled battery. Examples of devices equipped with lithium ion secondary batteries include various home appliances driven by batteries such as personal computers and portable communication devices, office devices, and industrial devices in addition to vehicles. Furthermore, the lithium ion secondary battery of the present invention includes wind power generation, solar power generation, hydroelectric power generation and other power system power storage devices and power smoothing devices, power supplies for ships and / or auxiliary power supply sources, aircraft, Power supply for spacecraft and / or auxiliary equipment, auxiliary power supply for vehicles that do not use electricity as a power source, power supply for mobile home robots, power supply for system backup, power supply for uninterruptible power supply, You may use for the electrical storage apparatus which stores temporarily the electric power required for charge in the charging station for electric vehicles.
　以上、本発明の実施形態を説明したが、本発明は、上記実施形態に限定されるものではない。本発明の要旨を逸脱しない範囲において、当業者が行い得る変更、改良等を施した種々の形態にて実施することができる。 As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. The present invention can be implemented in various forms without departing from the gist of the present invention, with modifications and improvements that can be made by those skilled in the art.
　以下に、実施例及び比較例を示し、本発明をより具体的に説明する。なお、本発明は、これらの実施例によって限定されるものではない。 Hereinafter, the present invention will be described more specifically by showing examples and comparative examples. In addition, this invention is not limited by these Examples.
（実施例１）
　図２に示すプラズマ発生装置を用いて、実施例１の粉末を製造した。図２におけるプラズマ発生装置において、粉体供給器１より原料粉体が供給され、キャリヤーガス経路６を通じて原料粉体がプラズマ発生装置内１１に導入される。キャリヤーガスはキャリヤーガス経路６を通じてプラズマ発生装置内１１に導入され、プロセスガスはプロセスガス経路７を通じてプラズマ発生装置内１１に導入され、インナーガスはインナーガス経路８を通じてプラズマ発生装置内１１に導入される。電力供給装置２によって電力が供給され、プラズマ発生装置内１１にプラズマが発生する。冷却ガス経路９を通じて運ばれた冷却ガスはプラズマ内を通過した後の通過流に対向する方向に噴射される。冷却ガス供給管９１の開口とプラズマ発生装置内１１の開口との距離は２００ｍｍであった。また各ガスはフィルター４が設けられている排気部３を通じて装置外に排気される。製造物は自重で落下し、内部チャンバー５の下部に収容される。図２に示すプラズマ発生装置において、白抜き矢印は冷却水を表す。 Example 1
The powder of Example 1 was manufactured using the plasma generator shown in FIG. In the plasma generator in FIG. 2, the raw material powder is supplied from the powder supplier 1, and the raw material powder is introduced into the plasma generator 11 through the carrier gas path 6. The carrier gas is introduced into the plasma generator 11 through the carrier gas path 6, the process gas is introduced into the plasma generator 11 through the process gas path 7, and the inner gas is introduced into the plasma generator 11 through the inner gas path 8. The Power is supplied by the power supply device 2, and plasma is generated in the plasma generator 11. The cooling gas carried through the cooling gas path 9 is injected in a direction opposite to the passing flow after passing through the plasma. The distance between the opening of the cooling gas supply pipe 91 and the opening of the plasma generator 11 was 200 mm. Each gas is exhausted out of the apparatus through an exhaust section 3 provided with a filter 4. The product falls by its own weight and is stored in the lower part of the internal chamber 5. In the plasma generator shown in FIG. 2, the white arrow represents the cooling water.
　原料Ｓｉ粉末として、Ｄ５０が３μｍのＳｉ粉末（株式会社高純度化学研究所製、品番ＳＩＥ２３ＰＢ）を準備した。 As the raw material Si powder, Si powder having a D 50 of 3 μm (manufactured by Kojundo Chemical Laboratory Co., Ltd., product number SIE23PB) was prepared.
　原料Ｓｉ粉末を粉体供給器に配置した。
　プラズマ発生装置内に、プロセスガスとしてアルゴンガスを６０Ｌ／ｍｉｎ．で供給し、インナーガスとしてアルゴンガスを５Ｌ／ｍｉｎ．で供給し、キャリヤーガスとしてアルゴンガスを３Ｌ／ｍｉｎ．で供給し、冷却ガスとしてメタンガスを０．３２Ｌ／ｍｉｎ．で供給した。メタンガスの流速は、供給管に取り付けた浮き子式流量計を用いて測定した。この時、電力供給装置から電力を供給し、周波数４ＭＨｚの磁場をコイルに印加して、出力１０ｋＷのプラズマを発生させた。なお、プラズマ発生装置内の圧力は大気圧とした。 The raw material Si powder was placed in a powder feeder.
In the plasma generator, argon gas as a process gas was added at 60 L / min. At 5 L / min. As an inner gas. At a flow rate of 3 L / min. Methane gas as a cooling gas at 0.32 L / min. Supplied with. The flow rate of methane gas was measured using a float type flow meter attached to the supply pipe. At this time, power was supplied from the power supply device, and a magnetic field with a frequency of 4 MHz was applied to the coil to generate plasma with an output of 10 kW. The pressure in the plasma generator was atmospheric pressure.
　プラズマの安定後、粉体供給器を作動させ、原料Ｓｉ粉体を４００ｍｇ／ｍｉｎ．の速度で、キャリヤーガスとともに、プラズマ内へ導入した。プラズマ内を通過した後の通過流とともに放出された粉末を収集し、酸素雰囲気下で１時間保持した。得られた粉末を実施例１の粉末とした。単位時間当たりの原料Ｓｉ粉末の供給モル数に対する単位時間当たりの炭素源ガスの供給モル数の比であるＣ／Ｓｉは１．０である。 After the plasma is stabilized, the powder feeder is operated, and the raw material Si powder is 400 mg / min. Was introduced into the plasma together with the carrier gas at a rate of The powder released along with the flow after passing through the plasma was collected and held in an oxygen atmosphere for 1 hour. The obtained powder was used as the powder of Example 1. C / Si, which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, is 1.0.
(形態観察)
　実施例１の粉末断面をＳＥＭ観察した。断面ＳＥＭ観察結果を図３、図４、図５に示す。図４は図３の１０倍倍率の結果であり、図５は図３の１００倍倍率での結果である。図３、図４、図５には、凝集体の形態を有する被膜付きＳｉ粒子結合体が観察された。図４には、Ｓｉ粒子が凝集体の中で分散している様子が明確に観察された。 (Morphological observation)
The powder cross section of Example 1 was observed by SEM. Cross-sectional SEM observation results are shown in FIG. 3, FIG. 4, and FIG. FIG. 4 shows the result of 10 × magnification of FIG. 3, and FIG. 5 shows the result of 100 × magnification of FIG. In FIG. 3, FIG. 4, and FIG. 5, a coated Si particle combination having the form of an aggregate was observed. In FIG. 4, it was clearly observed that the Si particles were dispersed in the aggregate.
　断面ＳＥＭ観察結果から、実施例１の粉末のＳｉ粒子結合体の凝集体全体の長手方向の大きさを測定した。Ｓｉ粒子結合体の凝集体を１００個測定した結果、実施例１の粉末のＳｉ粒子結合体の凝集体全体の長手方向の大きさは、２０μｍ以上１５０μｍ以下であった。 From the cross-sectional SEM observation results, the size in the longitudinal direction of the aggregate of the powder Si particle aggregate of Example 1 was measured. As a result of measuring 100 aggregates of the Si particle aggregate, the size in the longitudinal direction of the entire Si particle aggregate of the powder of Example 1 was 20 μm or more and 150 μm or less.
　次に、実施例１の粉末をＴＥＭ観察した。実施例１の粉末のＴＥＭ観察結果を図６に示す。図６には、Ｓｉ粒子１０と、繊維状Ｓｉ２０が観察された。図６には、Ｓｉ粒子１０には、複数の繊維状Ｓｉが結合しており、また繊維状Ｓｉ２０は複数のＳｉ粒子と結合していることが観察された。また、図６には、繊維状Ｓｉの繊維径は１０ｎｍ程度であること、Ｓｉ粒子の粒径は１００ｎｍ程度であることが観察された。 Next, the powder of Example 1 was observed with a TEM. The TEM observation result of the powder of Example 1 is shown in FIG. In FIG. 6, Si particles 10 and fibrous Si20 were observed. In FIG. 6, it was observed that a plurality of fibrous Si was bonded to the Si particles 10 and that the fibrous Si 20 was bonded to a plurality of Si particles. Moreover, in FIG. 6, it was observed that the fiber diameter of fibrous Si is about 10 nm, and the particle diameter of Si particle is about 100 nm.
　ＴＥＭ観察結果から、実施例１の粉末のＳｉ粒子の粒径を測定した。実施例１の粉末の各Ｓｉ粒子の長径を２００個分測定した。実施例１の粉末のＳｉ粒子の粒径は、３０ｎｍ以上１０００ｎｍ未満であった。測定数値を用いて実施例１の粉末のＳｉ粒子の粒度分布図を作成した。粒度分布図を図７に示す。実施例１の粉末のＳｉ粒子のＤ５０は、７０ｎｍであった。 From the TEM observation results, the particle size of the Si particles of the powder of Example 1 was measured. 200 major axes of each Si particle of the powder of Example 1 were measured. The particle size of the Si particles in the powder of Example 1 was not less than 30 nm and less than 1000 nm. A particle size distribution diagram of the Si particles of the powder of Example 1 was created using the measured numerical values. A particle size distribution diagram is shown in FIG. The D 50 of the Si particles of the powder of Example 1 was 70 nm.
　実施例１の粉末のＴＥＭ観察結果から、繊維状Ｓｉの繊維径を測定した。実施例１の粉末の各繊維状Ｓｉの繊維径を１００個分測定した。繊維状Ｓｉの繊維径は８ｎｍ以上１５ｎｍ以下であった。測定値より算出した実施例１の粉末の繊維状Ｓｉの繊維径の算術平均値は１０ｎｍであった。 From the TEM observation result of the powder of Example 1, the fiber diameter of fibrous Si was measured. 100 fiber diameters of each fibrous Si of the powder of Example 1 were measured. The fiber diameter of fibrous Si was 8 nm or more and 15 nm or less. The arithmetic average value of the fiber diameter of fibrous Si of the powder of Example 1 calculated from the measured value was 10 nm.
　実施例１の粉末のＴＥＭ観察結果から、繊維状Ｓｉの繊維長を測定した。実施例１の粉末の各繊維状Ｓｉの繊維長を１００個分測定した。繊維状Ｓｉの繊維長は３０ｎｍ以上１μｍ以下であった。 From the TEM observation result of the powder of Example 1, the fiber length of fibrous Si was measured. 100 fiber lengths of each fibrous Si of the powder of Example 1 were measured. The fiber length of the fibrous Si was 30 nm or more and 1 μm or less.
　実施例１の粉末のＳｉ粒子結合体の表面を透過型電子顕微鏡－エネルギー分散型Ｘ線分光法（以下、ＴＥＭ－ＥＤＳと称す。）で観察した。結果を図８に示す。さらに図８の観察結果を模式図にして図９に示す。図８において、Ｓｉ粒子１０の表面及びＳｉ粒子１０と繊維状Ｓｉとの結合部５０の表面には、厚み２ｎｍの被膜６０が形成されていることが観察された。ＴＥＭ－ＥＤＳ測定によれば、Ｓｉ粒子１０においてＳｉが測定され、かつ結合部５０の中心部においてＳｉが測定された。つまり、結合部５０において、繊維状ＳｉとＳｉ粒子１０とは一体化していることが観察された。また、被膜はＳｉ粒子にも繊維状Ｓｉにも結合部にも観察されたことから、被膜はＳｉ粒子結合体の構造を補強する効果をなしていることが推測される。 The surface of the powder Si particle combination of Example 1 was observed with a transmission electron microscope-energy dispersive X-ray spectroscopy (hereinafter referred to as TEM-EDS). The results are shown in FIG. Further, the observation result of FIG. 8 is schematically shown in FIG. In FIG. 8, it was observed that a coating 60 having a thickness of 2 nm was formed on the surface of the Si particles 10 and the surface of the bonding portion 50 between the Si particles 10 and fibrous Si. According to the TEM-EDS measurement, Si was measured in the Si particles 10, and Si was measured in the central portion of the bonding portion 50. That is, it was observed that the fibrous Si and the Si particles 10 were integrated in the joint portion 50. Further, since the coating was observed on both the Si particles, the fibrous Si, and the bonding portion, it is presumed that the coating has an effect of reinforcing the structure of the Si particle bonded body.
　また、ＴＥＭ－ＥＤＳ測定によれば、被膜６０にはＣとＯとが測定された。被膜６０にＣとＯとが含まれるメカニズムとして、以下のことが考えられる。実施例１の粉末の製造時に、プラズマ内を通過した後の粉末は、酸素雰囲気下で１時間保持された。プラズマ内を通過した後の粉末の表面には、ラジカル状態のＣＨが存在することが推測される。そのため、ラジカル状態のＣＨを有する被膜を酸素含有雰囲気下におくと、ラジカル状態のＣＨに酸素が結合し、被膜に容易に酸素が導入される。その結果、粉末の表面の被膜６０にＣとＯとが含まれることになったと推測される。 Further, according to the TEM-EDS measurement, C and O were measured on the film 60. The following can be considered as a mechanism in which C and O are contained in the film 60. During the production of the powder of Example 1, the powder after passing through the plasma was held for 1 hour in an oxygen atmosphere. It is presumed that CH in a radical state exists on the surface of the powder after passing through the plasma. Therefore, when a film having CH in a radical state is placed in an oxygen-containing atmosphere, oxygen is bonded to CH in the radical state, and oxygen is easily introduced into the film. As a result, it is presumed that C and O are contained in the coating 60 on the surface of the powder.
　実施例１の粉末のＴＥＭ観察結果の模式図を図１０に示す。ＴＥＭ観察において、図１０に示す、２個のＳｉ粒子１０と、Ｓｉ粒子１０を連結する繊維状Ｓｉ２０が観察された。さらに、図１０における繊維状Ｓｉ２０を透過型電子顕微鏡－電子エネルギー損失分光法（以下、ＴＥＭ－ＥＥＬＳと称す。）で観察した。ＴＥＭ－ＥＥＬＳ観察結果を図１１に示す。また、図１１の観察結果を模式図にして図１２に示す。図１１において、ＴＥＭ－ＥＥＬＳ測定によれば、繊維状Ｓｉの表面には被膜が観察された。ＴＥＭ－ＥＥＬＳ測定により得られた損失スペクトルにより、繊維状Ｓｉにおいて、結晶性Ｓｉが測定された。また、被膜においては、ＣとＯとが測定された。 A schematic diagram of the TEM observation result of the powder of Example 1 is shown in FIG. In the TEM observation, two Si particles 10 shown in FIG. 10 and fibrous Si20 connecting the Si particles 10 were observed. Further, the fibrous Si20 in FIG. 10 was observed with a transmission electron microscope-electron energy loss spectroscopy (hereinafter referred to as TEM-EELS). The results of TEM-EELS observation are shown in FIG. Further, the observation result of FIG. 11 is schematically shown in FIG. In FIG. 11, according to the TEM-EELS measurement, a film was observed on the surface of the fibrous Si. From the loss spectrum obtained by TEM-EELS measurement, crystalline Si was measured in fibrous Si. In the coating, C and O were measured.
 (実施例２) 
　冷却ガスとしてアルゴンガスを２０Ｌ／ｍｉｎ．で供給し、メタンガスを供給しなかった以外は実施例１の粉末と同様にして実施例２の粉末を製造した。単位時間当たりの原料Ｓｉ粉末の供給モル数に対する単位時間当たりの炭素源ガスの供給モル数の比であるＣ／Ｓｉは０であった。 (Example 2)
Argon gas was used as a cooling gas at 20 L / min. The powder of Example 2 was produced in the same manner as the powder of Example 1 except that methane gas was not supplied. C / Si, which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 0.
 (実施例３)
　冷却ガスとしてメタンガスを０．１６Ｌ／ｍｉｎ．で、供給した以外は、実施例１の粉末と同様にして実施例３の粉末を製造した。単位時間当たりの原料Ｓｉ粉末の供給モル数に対する単位時間当たりの炭素源ガスの供給モル数の比であるＣ／Ｓｉは０．５であった。 Example 3
As a cooling gas, methane gas is 0.16 L / min. Thus, the powder of Example 3 was produced in the same manner as the powder of Example 1 except that it was supplied. C / Si, which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 0.5.
 (実施例４)
　冷却ガスとしてメタンガスを０．４８Ｌ／ｍｉｎ．で、供給した以外は実施例１の粉末と同様にして実施例４の粉末を製造した。単位時間当たりの原料Ｓｉ粉末の供給モル数に対する単位時間当たりの炭素源ガスの供給モル数の比であるＣ／Ｓｉは１．５であった。 Example 4
As a cooling gas, methane gas is 0.48 L / min. Thus, the powder of Example 4 was produced in the same manner as the powder of Example 1 except that it was supplied. C / Si, which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 1.5.
 (実施例５)
　冷却ガスとしてメタンガスを０．５７６Ｌ／ｍｉｎ．で供給した以外は実施例１の粉末と同様にして実施例５の粉末を製造した。単位時間当たりの原料Ｓｉ粉末の供給モル数に対する単位時間当たりの炭素源ガスの供給モル数の比であるＣ／Ｓｉは１．８であった。 (Example 5)
Methane gas is used as the cooling gas at 0.576 L / min. A powder of Example 5 was produced in the same manner as the powder of Example 1 except that the powder was supplied in Step 1. C / Si, which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 1.8.
 (実施例６)
　冷却ガスとしてメタンガスを０．６４Ｌ／ｍｉｎ．で供給した以外は実施例１の粉末と同様にして実施例６の粉末を製造した。単位時間当たりの原料Ｓｉ粉末の供給モル数に対する単位時間当たりの炭素源ガスの供給モル数の比であるＣ／Ｓｉは２．０であった。 Example 6
As a cooling gas, methane gas is 0.64 L / min. A powder of Example 6 was produced in the same manner as the powder of Example 1 except that the powder was supplied in Step 6. C / Si, which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 2.0.
 (実施例７)
　冷却ガス供給管の開口とプラズマ発生装置内の開口との距離を１５０ｍｍとし、冷却ガスとしてメタンガスを０．５６Ｌ／ｍｉｎ．で供給し、原料Ｓｉ粉体を７００ｍｇ／ｍｉｎ．の速度とした以外は、実施例１の粉末と同様にして実施例７の粉末を製造した。単位時間当たりの原料Ｓｉ粉末の供給モル数に対する単位時間当たりの炭素源ガスの供給モル数の比であるＣ／Ｓｉは１であった。 (Example 7)
The distance between the opening of the cooling gas supply pipe and the opening in the plasma generator is 150 mm, and methane gas is used as the cooling gas at 0.56 L / min. At a raw material Si powder of 700 mg / min. The powder of Example 7 was produced in the same manner as the powder of Example 1, except that the speed was changed. C / Si, which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 1.
 (比較例１)
　プラズマ出力を１５ｋＷとした以外は、実施例１の粉末と同様にして比較例１の粉末を得た。 (Comparative Example 1)
A powder of Comparative Example 1 was obtained in the same manner as the powder of Example 1 except that the plasma output was 15 kW.
(比較例２)
　プラズマ出力を２０ｋＷとした以外は、実施例１の粉末と同様にして比較例２の粉末を得た。 (Comparative Example 2)
A powder of Comparative Example 2 was obtained in the same manner as the powder of Example 1 except that the plasma output was 20 kW.
（ＴＥＭ観察結果）
　実施例１～実施例７の粉末のＴＥＭ観察を行なった。実施例２の粉末において、Ｓｉ粒子一個とそのＳｉ粒子に結合する繊維状Ｓｉ一個の組み合わせのＳｉ粒子結合体が多く観察された。実施例３の粉末において、Ｓｉ粒子一個とそのＳｉ粒子に結合する繊維状Ｓｉ一個の組み合わせのＳｉ粒子結合体が多く観察された。また、実施例７の粉末において、Ｓｉ粒子一個とそのＳｉ粒子に結合する繊維状Ｓｉ一個の組み合わせのＳｉ粒子結合体が多く観察された。また、実施例７の粉末において、繊維状Ｓｉの繊維長は、実施例１～６の粉末における繊維状Ｓｉの繊維長に比べて短かった。実施例１の粉末、実施例４～６の粉末において、複数のＳｉ粒子と複数の繊維状Ｓｉの組み合わせのＳｉ粒子結合体が多く観察された。 (TEM observation result)
TEM observation of the powders of Examples 1 to 7 was performed. In the powder of Example 2, many Si particle combinations of one Si particle and a combination of one fibrous Si bonded to the Si particle were observed. In the powder of Example 3, many Si particle combinations of one Si particle and a combination of one fibrous Si bonded to the Si particle were observed. Further, in the powder of Example 7, many Si particle combinations of one Si particle and a combination of one fibrous Si bonded to the Si particle were observed. Further, in the powder of Example 7, the fiber length of fibrous Si was shorter than the fiber length of fibrous Si in the powders of Examples 1 to 6. In the powder of Example 1 and the powders of Examples 4 to 6, many Si particle combinations of a combination of a plurality of Si particles and a plurality of fibrous Si were observed.
　実施例１～６の粉末のＴＥＭ観察結果から、Ｃ／Ｓｉ比が高いほど複数のＳｉ粒子と複数の繊維状Ｓｉの組み合わせのＳｉ粒子結合体になりやすいと考えられた。 From the TEM observation results of the powders of Examples 1 to 6, it was considered that the higher the C / Si ratio, the easier it is to form a Si particle combination of a plurality of Si particles and a plurality of fibrous Si.
（ＳｉのＸＰＳ分析）
　実施例１の粉末、比較例１の粉末及び比較例２の粉末の各表面のＳｉの構造をＸＰＳで分析した。図１３には、各試料のＳｉ２ｐの高分解能スペクトルを並記して示す。図の横軸は結合エネルギー（ｅＶ）であり、縦軸は強度（ａ．ｕ．）である。図１３に示すように、実施例１の粉末のＳｉ２ｐの高分解能スペクトルにおいて、９９ｅｖ近辺と１０４ｅＶ近辺にピークが観察された。９９ｅＶ近辺のピークはＳｉ－Ｓｉ結合に由来するピークであり、１０４ｅＶ近辺のピークはＳｉＯ２に由来するピークである。実施例１の粉末に対して、比較例１の粉末及び比較例２の粉末のＳｉ２ｐの高分解能スペクトルにおいて、９９ｅｖ近辺と１０４ｅＶ近辺にピークは観察されず、１０２ｅＶ近辺にピークが観察された。１０２ｅＶ近辺のピークはＳｉＣに由来するピークである。このことから、プラズマ出力が１５ｋＷ以上であると、ＳｉはＣと化学反応を起こしてＳｉＣになりやすいことが確認された。 (XPS analysis of Si)
The structure of Si on each surface of the powder of Example 1, the powder of Comparative Example 1, and the powder of Comparative Example 2 was analyzed by XPS. In FIG. 13, the high-resolution spectrum of Si2p of each sample is shown side by side. In the figure, the horizontal axis represents the binding energy (eV), and the vertical axis represents the strength (au). As shown in FIG. 13, in the high-resolution spectrum of Si2p of the powder of Example 1, peaks were observed around 99 ev and around 104 eV. The peak near 99 eV is a peak derived from Si—Si bond, and the peak near 104 eV is a peak derived from SiO 2 . In the high-resolution spectra of Si2p of the powder of Comparative Example 1 and the powder of Comparative Example 2 with respect to the powder of Example 1, no peaks were observed near 99 ev and 104 eV, and peaks were observed near 102 eV. The peak in the vicinity of 102 eV is a peak derived from SiC. From this, it was confirmed that when the plasma output is 15 kW or more, Si causes a chemical reaction with C and easily becomes SiC.
（被膜の解析１－１）
　実施例１の粉末の被膜、比較例１の粉末の被膜及び比較例２の粉末の被膜について、ラマン分光装置を用いて、ラマンスペクトルを測定した。図１４に実施例１の粉末の被膜、比較例１の粉末の被膜及び比較例２の粉末の被膜の各ラマンスペクトルを示す。図の横軸は波数（ｃｍ－１）であり、縦軸は散乱強度である。測定条件は波長５３２ｎｍ、測定範囲４５０ｃｍ－１－１７００ｃｍ－１、測定時間３０秒、積算回数５０回とした。得られた実施例１の粉末、比較例１の粉末及び比較例２の粉末のラマン分光法によるラマンスペクトルには、１５９０ｃｍ－１付近に見られるＧバンドと１３５０ｃｍ－１付近に見られるＤバンドの両方のピークが観察された。Ｇバンドはグラファイトに起因するピークであり、Ｄバンドはアモルファスカーボン等のダングリングボンドを持つ炭素原子に起因するピークである。このことから、実施例１の粉末の被膜、比較例１の粉末の被膜及び比較例２の粉末の被膜にはグラファイトとアモルファスカーボンが含まれることが確認できた。また、実施例１の粉末のラマンスペクトルには、さらに、１２３０ｃｍ－１～１２７０ｃｍ－１、１４２０ｃｍ－１～１４８０ｃｍ－１の範囲にピークが観察された。これらのピークは比較例１の粉末及び比較例２の粉末のラマンスペクトルには見られなかった。１２３０ｃｍ－１～１２７０ｃｍ－１の範囲のピークはＳｉ－ＣＨ２及び／又はＳｉ－ＣＨ３に由来するピークであり、１４２０ｃｍ－１～１４８０ｃｍ－１の範囲のピークは、ＣＨ２及び／又はＣＨ３に由来するピークである。このことから、比較例１の粉末の被膜及び比較例２の粉末の被膜とは異なり、実施例１の粉末の被膜にはＨ元素が残っており、ＣＨ２及び／又はＣＨ３に由来する構造を有していることが確認された。 (Coating analysis 1-1)
The Raman spectrum of the powder film of Example 1, the powder film of Comparative Example 1, and the powder film of Comparative Example 2 was measured using a Raman spectrometer. FIG. 14 shows the Raman spectra of the powder coating of Example 1, the powder coating of Comparative Example 1, and the powder coating of Comparative Example 2. In the figure, the horizontal axis represents the wave number (cm −1 ), and the vertical axis represents the scattering intensity. The measurement conditions were a wavelength of 532 nm, a measurement range of 450 cm −1 -1700 cm −1 , a measurement time of 30 seconds, and an integration count of 50 times. Obtained in Examples 1 powder, the Raman spectra by powder of Comparative Example 1 and Comparative Example 2 powder Raman spectroscopy, the D band observed around G band and 1350 cm -1 observed around 1590 cm -1 Both peaks were observed. The G band is a peak due to graphite, and the D band is a peak due to carbon atoms having dangling bonds such as amorphous carbon. From this, it was confirmed that the powder coating of Example 1, the powder coating of Comparative Example 1, and the powder coating of Comparative Example 2 contained graphite and amorphous carbon. Also, the Raman spectra of the powder of Example 1, further, 1230 cm -1 ~ 1270 cm -1, a peak was observed in the range of 1420cm -1 ~ 1480cm -1. These peaks were not observed in the Raman spectra of the powder of Comparative Example 1 and the powder of Comparative Example 2. The peaks in the range of 1230 cm −1 to 1270 cm −1 are peaks derived from Si—CH 2 and / or Si—CH 3, and the peaks in the range of 1420 cm −1 to 1480 cm −1 are CH 2 and / or CH 3. It is a peak derived from. From this, unlike the powder coating of Comparative Example 1 and the powder coating of Comparative Example 2, the element H remains in the powder coating of Example 1, and the structure is derived from CH 2 and / or CH 3. It was confirmed that
　実施例１の粉末において被膜がＣＨ２及び／又はＣＨ３に由来する構造を有するメカニズムとしては、以下のことが考えられる。実施例１の粉末は、プラズマ出力が１０ｋＷで製造され、製造時に炭素源ガスを含む冷却ガスによって冷却された。炭素源ガスに含まれる炭化水素ガスは、熱プラズマによりＨの解離が進行する。Ｃ－Ｈ結合の解離エネルギーは約４８０ｋＪ／ｍｏｌであり、例えば、ＣＨ４からＨが全て解離するには約１６００ｋＪ／ｍｏｌのエネルギーが必要になる。実施例１の粉末の製造で使用されたプラズマ出力が１０ｋＷであり、プラズマ出力が１５ｋＷ及び２０ｋＷで製造された比較例１の粉末及び比較例２の粉末と比べて、実施例１の粉末の製造時のプラズマのエネルギーは小さい。そのため、実施例１の粉末の製造時には、プラズマ内を通過した通過流の有するエネルギーが小さくて、冷却ガスに含まれるＣＨ４は、Ｃ単体までは分解されずに、Ｈが残った状態でＳｉ表面を被覆したため、被膜はＣＨ２及び／又はＣＨ３に由来する構造を有するものになったと推測される。比較例１の粉末及び比較例２の粉末では、製造時のプラズマ出力が１５ｋＷ、２０ｋＷと実施例１の粉末の製造時より高エネルギーであったため、ＣＨ４はＣ単体まで分解されて、被膜はＣＨ２及び／又はＣＨ３に由来する構造を有さなかったものと推測される。 The following may be considered as a mechanism in which the coating in the powder of Example 1 has a structure derived from CH 2 and / or CH 3 . The powder of Example 1 was produced with a plasma output of 10 kW, and was cooled by a cooling gas containing a carbon source gas during production. In the hydrocarbon gas contained in the carbon source gas, dissociation of H proceeds by thermal plasma. The dissociation energy of C—H bond is about 480 kJ / mol. For example, in order to dissociate all H from CH 4 , energy of about 1600 kJ / mol is required. Production of the powder of Example 1 compared to the powder of Comparative Example 1 and the powder of Comparative Example 2 produced with the plasma power used in the production of the powder of Example 1 being 10 kW and the plasma power being 15 kW and 20 kW. The energy of the plasma is small. Therefore, when the powder of Example 1 is manufactured, the energy of the passing flow that has passed through the plasma is small, and CH 4 contained in the cooling gas is not decomposed to C alone, but remains in the state where H remains. Since the surface was coated, it is presumed that the film had a structure derived from CH 2 and / or CH 3 . In the powder of Comparative Example 1 and the powder of Comparative Example 2, the plasma output at the time of production was 15 kW and 20 kW, which was higher energy than at the time of production of the powder of Example 1, so CH 4 was decomposed to C alone, and the coating film was It is presumed that there was no structure derived from CH 2 and / or CH 3 .
（被膜の解析２）
　実施例１の粉末、実施例３の粉末、実施例４の粉末において、被膜に含まれるＣ、Ｏの構造をＸＰＳで分析した。実施例１の粉末、実施例３の粉末、実施例４の粉末の各被膜のＸＰＳ測定結果を図１５に示す。図の横軸は結合エネルギー（ｅＶ）であり、縦軸は強度（ａ．ｕ．）である。図１５に示すのは、各試料のＣ１ｓ軌道の高分解能スペクトルの並記である。図１５に示すように、各試料のＣ１ｓ軌道の高分解能スペクトルにおいて、共に２８７ｅＶ～２９０ｅＶにピークが観察された。２８７ｅＶ～２９０ｅＶに見られるピークは、Ｒ－ＣＯＯ－Ｒ’に由来するピークであると推定される。従って、被膜に含まれるＣ、Ｏの構造には、Ｏ＝Ｃ－Ｏが含まれると考えられる。従って、被膜はエステル骨格を有することが推測される。また、実施例１の粉末、実施例３の粉末、実施例４の粉末のＣ１ｓ軌道の高分解能スペクトルを比較すると、Ｃ／Ｓｉ比が増えるにつれて、２８７ｅＶ～２９０ｅＶに見られるピークは高エネルギー側にシフトしていることが観察された。 (Coating analysis 2)
In the powder of Example 1, the powder of Example 3, and the powder of Example 4, the structure of C and O contained in the coating was analyzed by XPS. FIG. 15 shows the XPS measurement results of the coating films of the powder of Example 1, the powder of Example 3, and the powder of Example 4. In the figure, the horizontal axis represents the binding energy (eV), and the vertical axis represents the strength (au). FIG. 15 shows a side-by-side description of the high-resolution spectrum of the C1s orbit of each sample. As shown in FIG. 15, peaks were observed at 287 eV to 290 eV in the high resolution spectrum of the C1s orbit of each sample. The peak observed at 287 eV to 290 eV is presumed to be a peak derived from R—COO—R ′. Therefore, it is considered that the structure of C and O included in the coating includes O═C—O. Therefore, it is estimated that the film has an ester skeleton. In addition, when the high resolution spectra of the C1s orbitals of the powder of Example 1, the powder of Example 3, and the powder of Example 4 are compared, the peak seen at 287 eV to 290 eV increases toward the high energy side as the C / Si ratio increases. A shift was observed.
（被膜の解析３）
　実施例４の粉末の被膜、並びに以下に示す参考例１の粉末の被膜及び参考例２の粉末の被膜を熱分解ガスクロマトグラフィーで測定した。測定での加熱条件は２５℃～２７０℃、昇温速度１０℃／ｍｉｎ．とした。２５℃～２７０℃の温度範囲において熱分解ガスクロマトグラフィーが吸着した物質を分析した。図１６に、実施例４の粉末の被膜、参考例１の粉末の被膜及び参考例２の粉末の被膜の測定結果を示す。なお、参考例１の粉末及び参考例２の粉末は以下の炭素被膜付きのＳｉ系の粉末である。 (Coating analysis 3)
The coating film of the powder of Example 4, the coating film of the powder of Reference Example 1 shown below, and the coating film of the powder of Reference Example 2 were measured by pyrolysis gas chromatography. The heating conditions in the measurement were 25 ° C. to 270 ° C., and the heating rate was 10 ° C./min. It was. Substances adsorbed by pyrolysis gas chromatography in the temperature range of 25 ° C. to 270 ° C. were analyzed. FIG. 16 shows the measurement results of the powder coating of Example 4, the powder coating of Reference Example 1, and the powder coating of Reference Example 2. The powder of Reference Example 1 and the powder of Reference Example 2 are the following Si-based powders with a carbon coating.
（参考例１）
　濃度３６質量％のＨＣｌ水溶液を氷浴中で０℃とし、アルゴンガス雰囲気下にてＣａＳｉ２を加えて撹拌した。発泡が完了したのを確認した後に混合溶液を室温まで昇温し、室温でさらに撹拌した後、蒸留水を加えてさらに撹拌した。得られた混合溶液を濾過し、得られた残渣を蒸留水で洗浄した後、エタノールで洗浄した。洗浄後の残渣を真空乾燥して層状ポリシランを得た。この層状ポリシランを、Ｏ２を１体積％以下の量で含むアルゴンガス中にて５００℃で１時間保持する熱処理を行なってから、粉砕し、Ｄ５０が５μｍのシリコン材料を得た。 (Reference Example 1)
An aqueous HCl solution having a concentration of 36% by mass was brought to 0 ° C. in an ice bath, and CaSi 2 was added and stirred under an argon gas atmosphere. After confirming the completion of foaming, the mixed solution was warmed to room temperature and further stirred at room temperature, and then distilled water was added and further stirred. The obtained mixed solution was filtered, and the obtained residue was washed with distilled water and then washed with ethanol. The residue after washing was vacuum dried to obtain layered polysilane. This layered polysilane was heat treated by holding it at 500 ° C. for 1 hour in an argon gas containing O 2 in an amount of 1% by volume or less, and then pulverized to obtain a silicon material having a D 50 of 5 μm.
　得られたシリコン材料をロータリーキルン型の反応器に入れ、２０体積％プロパンガス通気下にて８８０℃、滞留時間３０分間の条件で熱ＣＶＤ（Ｃｈｅｍｉｃａｌ　Ｖａｐｏｒ　Ｄｅｐｏｓｉｔｉｏｎ）を行って、炭素で被覆されたシリコン材料を得た。この炭素で被覆されたシリコン材料を参考例１の粉末とした。反応器の炉芯管は水平方向に配設されており、炉心管の回転速度は１ｒｐｍとした。炉心管の内周壁には邪魔板が配設されており、炉心管の回転に伴って邪魔板上に堆積した内容物が所定の高さで邪魔板から落下するように構成されているため、反応中に内容物が撹拌される。参考例１の粉末の被膜の厚みの平均値は１５ｎｍであった。 Silicon obtained by putting the obtained silicon material into a rotary kiln type reactor and performing thermal CVD (Chemical Vapor Deposition) under conditions of 880 ° C. and residence time of 30 minutes under 20% by volume of propane gas. Obtained material. The silicon material coated with carbon was used as the powder of Reference Example 1. The furnace core tube of the reactor was disposed in the horizontal direction, and the rotational speed of the core tube was 1 rpm. A baffle plate is disposed on the inner peripheral wall of the core tube, and the contents accumulated on the baffle plate with the rotation of the core tube are configured to fall from the baffle plate at a predetermined height. The contents are stirred during the reaction. The average thickness of the powder coating of Reference Example 1 was 15 nm.
(参考例２) 
　株式会社高純度化学研究所製、Ｄ５０が３μｍのＳｉ粉末を上記参考例１の粉末と同様にして、ロータリーキルンにて熱ＣＶＤを行なって炭素で被覆されたＳｉ粉末を作成した。この炭素で被覆されたＳｉ粉末を参考例２の粉末とした。参考例２の粉末の被膜の厚みの平均値は１５ｎｍであった。 (Reference example 2)
Si powder coated with carbon was produced by performing thermal CVD with a rotary kiln using Si powder having a D 50 of 3 μm manufactured by Kojundo Chemical Laboratory Co., Ltd. in the same manner as the powder of Reference Example 1 above. The Si powder coated with carbon was used as the powder of Reference Example 2. The average thickness of the powder coating of Reference Example 2 was 15 nm.
　図１６に示す熱分解ガスクロマトグラフィーの結果から、実施例４の粉末の被膜の熱分解物は、イソプレン骨格を有するテルペン類、及びエステル骨格を有する化合物を有することがわかった。この結果から、実施例４の粉末の被膜がイソプレン骨格及びエステル骨格を有することが示唆される。参考例１の粉末の被膜及び参考例２の粉末の被膜の熱分解ガスクロマトグラフィーの結果から、参考例１の粉末の被膜及び参考例２の粉末の被膜の熱分解物は、様々な鎖状炭化水素やナフタレンを有することが確認された。参考例１の粉末の被膜及び参考例２の粉末の被膜は、ロータリーキルン型の反応器において熱ＣＶＤ法でプロパンガスを熱分解してできた生成物によって形成された薄膜であった。このことから実施例４の粉末の被膜は、ロータリーキルン型の反応器において製造された被膜とは異なる被膜であるといえる。 From the results of pyrolysis gas chromatography shown in FIG. 16, it was found that the pyrolyzate of the powder coating of Example 4 had terpenes having an isoprene skeleton and a compound having an ester skeleton. This result suggests that the powder coating of Example 4 has an isoprene skeleton and an ester skeleton. From the results of pyrolysis gas chromatography of the powder coating of Reference Example 1 and the powder coating of Reference Example 2, the pyrolysis product of the powder coating of Reference Example 1 and the powder coating of Reference Example 2 has various chain shapes. It was confirmed to have hydrocarbons and naphthalene. The powder coating of Reference Example 1 and the powder coating of Reference Example 2 were thin films formed by products obtained by thermally decomposing propane gas by a thermal CVD method in a rotary kiln type reactor. From this, it can be said that the powder coating of Example 4 is a coating different from the coating manufactured in the rotary kiln type reactor.
（被膜の解析４）
　実施例７の粉末を分析したところ、Ｓｉ粒子の表面に多数のＳｉＣの結晶が存在することが確認できた。ＳｉＣの結晶の存在のため、実施例１の粉末の被膜に比べて、実施例７の粉末の被膜は、Ｓｉ粒子の表面の被覆面積が小さいことが推測される。実施例１と実施例７の粉末の製造条件において、実施例７の方が実施例１よりも冷却ガスの噴出口の位置がプラズマ発生装置内に近く、炭素源ガスとＳｉ粒子との接触時の温度が高くて、実施例７の粉末において、ＳｉＣが発生しやすかったと推察される。また、ＳｉＣが多く存在すると、製造時の酸素導入工程において、被膜に酸素が導入されにくいと推察される。従って、実施例７の粉末の被膜は、実施例１の粉末の被膜に比べて被膜に導入された酸素量が少なく、被膜に含まれるエステル骨格も少ないことが推察される。 (Coating analysis 4)
Analysis of the powder of Example 7 confirmed that a number of SiC crystals were present on the surface of the Si particles. Due to the presence of SiC crystals, the powder coating of Example 7 is estimated to have a smaller surface area of Si particles than the powder coating of Example 1. In the powder production conditions of Example 1 and Example 7, Example 7 was closer to the cooling gas jet outlet than in Example 1 in the plasma generator, and the carbon source gas and Si particles were in contact with each other. It is inferred that SiC was easily generated in the powder of Example 7 at a high temperature. In addition, when a large amount of SiC is present, it is assumed that oxygen is difficult to be introduced into the coating film in the oxygen introduction process during production. Therefore, it can be inferred that the powder film of Example 7 has a smaller amount of oxygen introduced into the film than the powder film of Example 1, and the ester skeleton contained in the film.
（酸素含有量の測定）
　実施例２の粉末、実施例３の粉末、実施例４の粉末、実施例６の粉末の酸素含有量を株式会社堀場製作所、酸素分析装置ＥＭＧＡ－８２０を用いて測定した。酸素含有量の測定結果を表１に示す。 (Measurement of oxygen content)
The oxygen content of the powder of Example 2, the powder of Example 3, the powder of Example 4, and the powder of Example 6 was measured using Horiba, Ltd., oxygen analyzer EMGA-820. Table 1 shows the measurement results of the oxygen content.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　実施例２の粉末は炭素含有被膜を有さないＳｉ粒子結合体からなるものである。実施例３の粉末、実施例４の粉末、実施例６の粉末は、炭素含有被膜を有するＳｉ粒子結合体からなるものである。酸素含有量の結果から、炭素含有被膜が形成されている粉末は、炭素含有被膜が形成されていない粉末に対して、粉末全体の酸素含有量が低くなることがわかった。従って、炭素含有被膜の存在によって、粉末全体の酸化が抑制されるといえる。また、Ｃ／Ｓｉ比が高いものの方が、粉末全体の酸素含有量が低くなることが確認された。このことから、Ｃ／Ｓｉ比が高いものの方が、炭素含有被膜はＳｉ粒子結合体の全体を均一に被覆していると推測される。 The powder of Example 2 is composed of a Si particle bonded body having no carbon-containing coating. The powder of Example 3, the powder of Example 4, and the powder of Example 6 are made of a Si particle combination having a carbon-containing coating. From the results of the oxygen content, it was found that the powder in which the carbon-containing film was formed had a lower oxygen content in the whole powder than the powder in which the carbon-containing film was not formed. Therefore, it can be said that the oxidation of the whole powder is suppressed by the presence of the carbon-containing coating. Moreover, it was confirmed that the one with a higher C / Si ratio has a lower oxygen content in the whole powder. From this, it is presumed that the carbon-containing coating uniformly coats the entire Si particle combination when the C / Si ratio is high.
（Ｓｉ結晶及びＳｉＣの確認）
　実施例１～４の粉末及び実施例６の粉末をＸＲＤ装置で測定し、結果のＸＲＤチャートを図１７に示す。図１７に見られるように、実施例１～４の粉末及び実施例６の粉末にはいずれもＳｉ結晶のピークが観察された。実施例１～４の粉末及び実施例６の粉末にはＳｉ結晶が存在することがわかった。また、実施例６の粉末にはＳｉＣが存在することがわかった。実施例１～４の粉末では、ＳｉＣの存在はほとんど確認できなかった。単位時間あたりの原料Ｓｉ粉末の供給モル数に対する単位時間当たりの炭素源ガスの供給モル数の比であるＣ／Ｓｉを１．５以下とすれば、ＳｉＣが形成されにくいことがわかった。 (Confirmation of Si crystal and SiC)
The powders of Examples 1 to 4 and the powder of Example 6 were measured with an XRD apparatus, and the resulting XRD chart is shown in FIG. As seen in FIG. 17, Si crystal peaks were observed in the powders of Examples 1 to 4 and the powder of Example 6. It was found that Si crystals were present in the powders of Examples 1 to 4 and the powder of Example 6. It was also found that SiC was present in the powder of Example 6. In the powders of Examples 1 to 4, the presence of SiC was hardly confirmed. It was found that if C / Si, which is the ratio of the number of moles of carbon source gas supplied per unit time to the number of moles of raw material Si powder supplied per unit time, is 1.5 or less, SiC is difficult to form.
＜リチウムイオン二次電池の製造＞
（実施例Ａ）
　以下のとおり、実施例Ａの負極及びリチウムイオン二次電池を製造した。
　負極活物質として実施例４の（Ｃ／Ｓｉ＝１．５）粉末７０質量部、天然黒鉛１５質量部、導電助剤としてアセチレンブラック５質量部、結着剤としてポリアクリル酸と４，４’－ジアミノジフェニルメタンとの混合物１０質量部を混合した。この混合物を適量のＮ－メチル－２－ピロリドンに分散させて、スラリー状の負極活物質層用組成物を製造した。 <Manufacture of lithium ion secondary batteries>
(Example A)
The negative electrode and lithium ion secondary battery of Example A were produced as follows.
70 parts by mass of the (C / Si = 1.5) powder of Example 4 as a negative electrode active material, 15 parts by mass of natural graphite, 5 parts by mass of acetylene black as a conductive additive, and polyacrylic acid as a binder, 4,4 ′ 10 parts by weight of a mixture with diaminodiphenylmethane were mixed. This mixture was dispersed in an appropriate amount of N-methyl-2-pyrrolidone to produce a slurry-like composition for a negative electrode active material layer.
　集電体として厚み２０μｍの銅箔を準備した。上記銅箔の表面に負極活物質層用組成物を載せ、ドクターブレードを用いて負極活物質層用組成物が膜状になるように塗布した。負極活物質層用組成物を塗布した銅箔を乾燥することで、Ｎ－メチル－２－ピロリドンを揮発により除去し、銅箔表面に負極活物質層を形成された実施例Ａの負極を製造した。なお、結着剤として用いたポリアクリル酸と４，４’－ジアミノジフェニルメタンとの混合物は、乾燥にて脱水反応が進行して、ポリアクリル酸を４，４’－ジアミノジフェニルメタンで架橋した架橋ポリマーに変化する。 A 20 μm thick copper foil was prepared as a current collector. The composition for negative electrode active material layers was placed on the surface of the copper foil, and the composition for negative electrode active material layers was applied to form a film using a doctor blade. The copper foil coated with the negative electrode active material layer composition was dried to remove N-methyl-2-pyrrolidone by volatilization, and the negative electrode of Example A in which the negative electrode active material layer was formed on the copper foil surface was produced. did. The mixture of polyacrylic acid and 4,4'-diaminodiphenylmethane used as the binder is a crosslinked polymer in which the dehydration reaction proceeds by drying and the polyacrylic acid is crosslinked with 4,4'-diaminodiphenylmethane. To change.
　上記の手順で作製した実施例Ａの負極を作用極として用い、リチウムイオン二次電池（ハーフセル）を作製した。対極は金属リチウム箔とした。作用極及び対極、並びに両極の間に介装させるセパレータ（ヘキストセラニーズ社製ガラスフィルター及びＣｅｌｇａｒｄ社製「Ｃｅｌｇａｒｄ２４００」）を配設して電極体とした。この電極体を電池ケース（ＣＲ２０３２型コイン電池用部材、宝泉株式会社製）に収容した。電池ケースに、エチレンカーボネートとジエチルカーボネートとを体積比１：１で混合した混合溶媒にＬｉＰＦ６を１Ｍの濃度で溶解した非水電解液を注入し、電池ケースを密閉して、実施例Ａのリチウムイオン二次電池を得た。 A lithium ion secondary battery (half cell) was produced using the negative electrode of Example A produced in the above procedure as a working electrode. The counter electrode was a metal lithium foil. A working electrode and a counter electrode, and a separator (Hoechst Celanese glass filter and Celgard “Celgard 2400”) interposed between the two electrodes were disposed to form an electrode body. This electrode body was accommodated in a battery case (CR2032-type coin battery member, manufactured by Hosen Co., Ltd.). Into the battery case, a nonaqueous electrolyte solution in which LiPF 6 was dissolved at a concentration of 1M was poured into a mixed solvent in which ethylene carbonate and diethyl carbonate were mixed at a volume ratio of 1: 1, the battery case was sealed, and the battery of Example A was sealed. A lithium ion secondary battery was obtained.
（比較例Ａ）
　実施例４の粉末に代えて参考例１の粉末を用いた以外は、実施例Ａと同様の方法で、比較例Ａの負極及び比較例Ａのリチウムイオン二次電池を製造した。 (Comparative Example A)
A negative electrode of Comparative Example A and a lithium ion secondary battery of Comparative Example A were produced in the same manner as in Example A, except that the powder of Reference Example 1 was used instead of the powder of Example 4.
（実施例Ｂ）
　負極活物質として実施例４の（Ｃ／Ｓｉ＝１．５）粉末４０質量部、天然黒鉛４０質量部、導電助剤としてアセチレンブラック５質量部、結着剤としてポリアミドイミド樹脂１５質量部を混合し、この混合物を適量のＮ－メチル－２－ピロリドンに分散させて、スラリー状の負極活物質層用組成物を製造した以外は、実施例Ａの負極と同様にして、実施例Ｂの負極を製造した。そして、実施例Ｂの負極を用いた以外は実施例Ａのリチウムイオン二次電池と同様にして実施例Ｂのリチウムイオン二次電池を製造した。 (Example B)
40 parts by mass of the (C / Si = 1.5) powder of Example 4 as a negative electrode active material, 40 parts by mass of natural graphite, 5 parts by mass of acetylene black as a conductive additive, and 15 parts by mass of polyamideimide resin as a binder The negative electrode of Example B was prepared in the same manner as the negative electrode of Example A, except that this mixture was dispersed in an appropriate amount of N-methyl-2-pyrrolidone to produce a slurry-like composition for negative electrode active material layer. Manufactured. And the lithium ion secondary battery of Example B was manufactured like the lithium ion secondary battery of Example A except having used the negative electrode of Example B.
（実施例Ｃ）
　実施例４の粉末に代えて実施例３の（Ｃ／Ｓｉ＝０．５）粉末を用いた以外は実施例Ｂと同様にして実施例Ｃのリチウムイオン二次電池を製造した。 (Example C)
A lithium ion secondary battery of Example C was produced in the same manner as Example B, except that the powder (C / Si = 0.5) of Example 3 was used instead of the powder of Example 4.
（実施例Ｄ）
　実施例４の粉末に代えて実施例７の粉末を用いた以外は実施例Ｂと同様にして実施例Ｄのリチウムイオン二次電池を製造した。 (Example D)
A lithium ion secondary battery of Example D was produced in the same manner as Example B except that the powder of Example 7 was used instead of the powder of Example 4.
　＜充放電曲線測定＞
（評価例１）
　実施例Ａ及び比較例Ａのリチウムイオン二次電池の充放電曲線を測定した。室温で、１．０Ｖから０．０１Ｖまでの放電及び０．０１Ｖから１．０Ｖまでの充電を、０．１Ｃレート相当の０．２ｍＡで行なった。この時の充放電曲線を図１８に示す。実施例Ａの放電容量は１６２５ｍＡｈ／ｇであり、比較例Ａの放電容量は、１５７４ｍＡｈ／ｇであった。また、実施例Ａの充電容量は１３３８ｍＡｈ／ｇであり、比較例Ａの充電容量は、１２３９ｍＡｈ／ｇであった。このことから、実施例Ａのリチウムイオン二次電池の放電容量は、比較例Ａのリチウムイオン二次電池の放電容量よりも大きいことがわかった。実施例Ａの負極に用いられた実施例４の粉末に含まれるＳｉ粒子結合体は繊維状Ｓｉを有するため、比較例Ａの負極に用いられた参考例１の粉末に比べて、表面積が大きく、リチウムイオン二次電池の放電容量が大きくなったものと推測される。 <Charge / discharge curve measurement>
(Evaluation example 1)
The charge / discharge curves of the lithium ion secondary batteries of Example A and Comparative Example A were measured. At room temperature, discharging from 1.0 V to 0.01 V and charging from 0.01 V to 1.0 V were performed at 0.2 mA corresponding to a 0.1 C rate. The charge / discharge curve at this time is shown in FIG. The discharge capacity of Example A was 1625 mAh / g, and the discharge capacity of Comparative Example A was 1574 mAh / g. Moreover, the charging capacity of Example A was 1338 mAh / g, and the charging capacity of Comparative Example A was 1239 mAh / g. From this, it was found that the discharge capacity of the lithium ion secondary battery of Example A was larger than the discharge capacity of the lithium ion secondary battery of Comparative Example A. Since the Si particle combination contained in the powder of Example 4 used for the negative electrode of Example A has fibrous Si, the surface area is larger than that of the powder of Reference Example 1 used for the negative electrode of Comparative Example A. It is estimated that the discharge capacity of the lithium ion secondary battery has increased.
　また、各充電容量及び放電容量から初期効率を算出した。初期効率は下記の式から算出した。初期効率（％）＝（充電容量／放電容量）×１００
　実施例Ａのリチウムイオン二次電池の初期効率は８２．３％であり、比較例Ａのリチウムイオン二次電池の初期効率は７８．７％であった。このことから、Ｓｉ粒子結合体を用いた実施例Ａのリチウムイオン二次電池は、参考例１の粉末を用いた比較例Ａのリチウムイオン二次電池に比べて、初期効率が高いことが確認された。 The initial efficiency was calculated from each charge capacity and discharge capacity. The initial efficiency was calculated from the following formula. Initial efficiency (%) = (charge capacity / discharge capacity) × 100
The initial efficiency of the lithium ion secondary battery of Example A was 82.3%, and the initial efficiency of the lithium ion secondary battery of Comparative Example A was 78.7%. From this, it was confirmed that the lithium ion secondary battery of Example A using the Si particle combination had higher initial efficiency than the lithium ion secondary battery of Comparative Example A using the powder of Reference Example 1. It was done.
　ここで、実施例Ａのリチウムイオン二次電池と比較例Ａのリチウムイオン二次電池の放電曲線を比較すると、比較例Ａのリチウムイオン二次電池の放電曲線では、Ｘ軸における０ｍＡｈ／ｇ～３００ｍＡｈ／ｇの近辺で、実施例Ａのリチウムイオン二次電池の放電曲線よりも電位が高いことが観察された。この電位は電解液の分解電流によるものと推測される。実施例Ａのリチウムイオン二次電池の放電曲線では、この電位が高い部分は観測されなかったことから、実施例Ａのリチウムイオン二次電池では電解液の分解が抑制されていると考えられる。上記被膜の解析２で記載したように、実施例Ａの負極に用いられた実施例４の粉末の被膜では、ＸＰＳ測定において、Ｒ－ＣＯＯ－Ｒ’に由来するピークが観察された。つまり、被膜はエステル骨格を有することが確認された。また、上記被膜の解析３で記載したように、熱分解クロマトグラフィーの結果から、比較例Ａの負極に用いられた参考例１の粉末の被膜の熱分解物は様々な鎖状炭化水素やナフタレンを有すること、それに対して、実施例Ａの負極に用いられた実施例４の粉末の被膜の熱分解物はイソプレン骨格を有するテルペン類やエステル骨格を有する化合物を有することが確認された。このことから、実施例Ａのリチウムイオン二次電池において、負極活物質の被膜がエステル骨格を有することにより、電解液の分解が抑制されると推察される。エステル骨格を有する被膜は、電解液で用いられる有機溶媒と構造が類似しており、また電解液で用いられる有機溶媒と類似の還元電位窓を有していると推測される。従って、エステル骨格を有する被膜が負極活物質の表面に存在することにより、電解液の分解が抑制されると推測される。図１８から、本発明の負極活物質又は第２負極活物質を具備する負極を具備するリチウムイオン二次電池は、電池容量、初期効率に優れていることが裏付けられた。 Here, when the discharge curves of the lithium ion secondary battery of Example A and the lithium ion secondary battery of Comparative Example A are compared, the discharge curve of the lithium ion secondary battery of Comparative Example A shows 0 mAh / g˜ It was observed that the potential was higher than the discharge curve of the lithium ion secondary battery of Example A at around 300 mAh / g. This potential is presumed to be due to the decomposition current of the electrolyte. In the discharge curve of the lithium ion secondary battery of Example A, the high potential portion was not observed. Therefore, it is considered that the decomposition of the electrolytic solution was suppressed in the lithium ion secondary battery of Example A. As described in Analysis 2 of the coating, in the powder coating of Example 4 used for the negative electrode of Example A, a peak derived from R—COO—R ′ was observed in the XPS measurement. That is, it was confirmed that the film has an ester skeleton. Moreover, as described in the analysis 3 of the coating film, the pyrolysis product of the powder coating film of Reference Example 1 used for the negative electrode of Comparative Example A shows that various chain hydrocarbons and naphthalene were used. In contrast, it was confirmed that the thermal decomposition product of the powder coating of Example 4 used for the negative electrode of Example A had terpenes having an isoprene skeleton and a compound having an ester skeleton. From this, in the lithium ion secondary battery of Example A, it is surmised that the coating of the negative electrode active material has an ester skeleton, thereby suppressing the decomposition of the electrolytic solution. The coating having an ester skeleton is presumed to be similar in structure to the organic solvent used in the electrolytic solution and have a reduction potential window similar to that of the organic solvent used in the electrolytic solution. Therefore, it is presumed that decomposition of the electrolytic solution is suppressed by the presence of the coating film having an ester skeleton on the surface of the negative electrode active material. From FIG. 18, it was confirmed that the lithium ion secondary battery including the negative electrode including the negative electrode active material or the second negative electrode active material of the present invention is excellent in battery capacity and initial efficiency.
（評価例２）
　実施例Ｂ、実施例Ｃ及び実施例Ｄのリチウムイオン二次電池の充放電曲線を測定した。室温で、１．０Ｖから０．０１Ｖまでの放電及び０．０１Ｖから１．０Ｖまでの充電を、０．１Ｃレート相当の０．２ｍＡで行なった。この時の充放電曲線を図１９に示す。図１９において、実施例Ｂのリチウムイオン二次電池の初期効率は７５．７％であり（（８６４／１１４２）×１００＝７５．７％）、実施例Ｃのリチウムイオン二次電池の初期効率は６０．５％であり（（８５１／１４０６）×１００＝６０．５％）、実施例Ｄのリチウムイオン二次電池の初期効率は５４．０％であった（（７９１／１４６６）×１００＝５４．０％）。粉末のＴＥＭ観察結果で記載したように、実施例Ｂのリチウムイオン二次電池に用いられた実施例４の粉末と、実施例Ｃのリチウムイオン二次電池に用いられた実施例３の粉末と、実施例Ｄのリチウムイオン二次電池に用いられた実施例７の粉末とを比較すると、実施例４の粉末において、複数のＳｉ粒子と複数の繊維状Ｓｉとの組み合わせを有するＳｉ粒子結合体が多く観察された。実施例３の粉末及び実施例７の粉末では、一個のＳｉ粒子と一個の繊維状Ｓｉとの組み合わせを有するＳｉ粒子結合体が多く観察された。このことから、複数のＳｉ粒子と複数の繊維状Ｓｉとの組み合わせを有するＳｉ粒子結合体では、リチウムイオン二次電池において、不可逆容量が少なくなって、初期効率が高くなることが推察される。 (Evaluation example 2)
The charge / discharge curves of the lithium ion secondary batteries of Example B, Example C, and Example D were measured. At room temperature, discharging from 1.0 V to 0.01 V and charging from 0.01 V to 1.0 V were performed at 0.2 mA corresponding to a 0.1 C rate. The charge / discharge curve at this time is shown in FIG. In FIG. 19, the initial efficiency of the lithium ion secondary battery of Example B is 75.7% ((864/1142) × 100 = 75.7%), and the initial efficiency of the lithium ion secondary battery of Example C is Was 60.5% ((851/1406) × 100 = 60.5%), and the initial efficiency of the lithium ion secondary battery of Example D was 54.0% ((791/1466) × 100 = 54.0%). As described in the TEM observation results of the powder, the powder of Example 4 used in the lithium ion secondary battery of Example B and the powder of Example 3 used in the lithium ion secondary battery of Example C In comparison with the powder of Example 7 used in the lithium ion secondary battery of Example D, in the powder of Example 4, an Si particle composite having a combination of a plurality of Si particles and a plurality of fibrous Si Many were observed. In the powder of Example 3 and the powder of Example 7, many Si particle combinations having a combination of one Si particle and one fibrous Si were observed. From this, it is surmised that in the Si particle combination having a combination of a plurality of Si particles and a plurality of fibrous Si, the irreversible capacity is reduced and the initial efficiency is increased in the lithium ion secondary battery.
　また、実施例Ｄのリチウムイオン二次電池と実施例Ｂ及び実施例Ｃのリチウムイオン二次電池の放電曲線を比較すると、実施例Ｄのリチウムイオン二次電池の放電曲線では、Ｘ軸における０ｍＡｈ／ｇ～３００ｍＡｈ／ｇの近辺で、実施例Ｂ及び実施例Ｃのリチウムイオン二次電池の放電曲線よりも電位が高いことがわかった。この電位は電解液の分解電流によるものと推測される。実施例Ｂ及び実施例Ｃのリチウムイオン二次電池の放電曲線ではこの電位が高い部分は観測されなかったことから、実施例Ｂ及び実施例Ｃのリチウムイオン二次電池では電解液の分解が抑制されていると考えられる。被膜の解析４で記載したように、実施例７の粉末の被膜のエステル骨格を有する割合が、実施例４及び実施例３の粉末の被膜のエステル骨格を有する割合よりも小さいと考えられる。そのため、粉末の被膜がエステル骨格をより多く有することで、電解液の分解を抑制する効果が高くなると推測される。 Further, when the discharge curves of the lithium ion secondary battery of Example D and the lithium ion secondary batteries of Example B and Example C are compared, the discharge curve of the lithium ion secondary battery of Example D shows 0 mAh on the X axis. It was found that the potential was higher than the discharge curves of the lithium ion secondary batteries of Examples B and C in the vicinity of / g to 300 mAh / g. This potential is presumed to be due to the decomposition current of the electrolyte. In the discharge curves of the lithium ion secondary batteries of Example B and Example C, the high potential portion was not observed. Therefore, in the lithium ion secondary batteries of Example B and Example C, the decomposition of the electrolyte was suppressed. It is thought that. As described in coating analysis 4, the proportion of the powder coating of Example 7 having an ester skeleton is considered to be smaller than the proportion of the coating of the powder coating of Example 4 and Example 3. Therefore, it is presumed that the effect of suppressing the decomposition of the electrolytic solution is increased when the powder film has more ester skeletons.
　＜サイクル特性評価＞
　実施例Ｂ、実施例Ｃ及び実施例Ｄのリチウムイオン二次電池に対し、室温で、１．０Ｖから０．０１Ｖまでの放電及び０．０１Ｖから１．０Ｖまでの充電を、０．５ｍＡで２０回行う充放電サイクル試験を行った。１回目の放電容量を初期容量とし、サイクル毎の放電容量を測定して、容量維持率を下記式から算出した。
容量維持率（％）＝（各サイクル時の放電容量／初期容量）×１００
　実施例Ｂ～実施例Ｄのリチウムイオン二次電池のサイクル数と容量維持率の関係を示すグラフを図２０に示す。 <Cycle characteristic evaluation>
With respect to the lithium ion secondary batteries of Example B, Example C, and Example D, at room temperature, discharging from 1.0 V to 0.01 V and charging from 0.01 V to 1.0 V were performed at 0.5 mA. A charge / discharge cycle test was conducted 20 times. The discharge capacity at the first time was used as the initial capacity, the discharge capacity for each cycle was measured, and the capacity retention rate was calculated from the following formula.
Capacity retention rate (%) = (discharge capacity at each cycle / initial capacity) × 100
A graph showing the relationship between the number of cycles and the capacity retention rate of the lithium ion secondary batteries of Examples B to D is shown in FIG.
　図２０から、実施例Ｂ、実施例Ｃ及び実施例Ｄのリチウムイオン二次電池は、２０サイクル目においても容量維持率が８０％以上であり、容量維持率に優れていることが確認された。実施例Ｂのリチウムイオン二次電池は、容量維持率が２０サイクル目においても９０％以上あり、特に優れていることが確認された。実施例Ｂのリチウムイオン二次電池に用いられる実施例４の粉末において、複数のＳｉ粒子と複数の繊維状Ｓｉとの組み合わせを有するＳｉ粒子結合体が多く観察された。複数のＳｉ粒子と複数の繊維状Ｓｉとの組み合わせを有するＳｉ粒子結合体では、多数の空隙を含むため、充放電時にＳｉが膨張、収縮しても、空隙が緩衝因子となって、Ｓｉ粒子結合体の全体の大きさの変動が特に少なかったと推測される。そのため、実施例Ｂのリチウムイオン二次電池は特に容量維持率が高くなったと考えられる。図２０から、本発明のリチウムイオン二次電池は、容量維持率に優れていることが裏付けられた。 From FIG. 20, it was confirmed that the lithium ion secondary batteries of Example B, Example C, and Example D had a capacity retention rate of 80% or more even in the 20th cycle and were excellent in capacity retention rate. . The lithium ion secondary battery of Example B had a capacity retention rate of 90% or more even at the 20th cycle, and was confirmed to be particularly excellent. In the powder of Example 4 used for the lithium ion secondary battery of Example B, many Si particle combinations having a combination of a plurality of Si particles and a plurality of fibrous Si were observed. Since the Si particle combination having a combination of a plurality of Si particles and a plurality of fibrous Si includes a large number of voids, even if Si expands and contracts during charge and discharge, the voids serve as a buffering factor, and the Si particles It is speculated that the variation in the overall size of the conjugate was particularly small. Therefore, it is considered that the capacity retention rate of the lithium ion secondary battery of Example B was particularly high. From FIG. 20, it was confirmed that the lithium ion secondary battery of the present invention is excellent in capacity retention rate.
 (実施例８)
　図２に示すプラズマ発生装置の一部を改良した装置を用いて、実施例８の粉末を製造した。改良装置においては、図２における冷却ガス供給管９１を複数の供給管とし、一部は希ガス供給管、他の一部は炭素源ガス供給管とした。希ガス供給管の開口とプラズマ発生装置内１１の開口との距離は１５０ｍｍとした。そして、炭素源ガス供給管の開口とプラズマ発生装置内１１の開口との距離は２００ｍｍとした。プラズマ発生装置内に、プロセスガスとしてアルゴンガスを６０Ｌ／ｍｉｎ．で供給し、インナーガスとしてアルゴンガスを５Ｌ／ｍｉｎ．で供給し、キャリヤーガスとしてアルゴンガスを３Ｌ／ｍｉｎ．で供給した。希ガス供給管から、希ガスとして、アルゴンガスを２０Ｌ／ｍｉｎ．で供給した。炭素源ガス供給管から、炭素源ガスとしてメタンガスを０．０９６Ｌ／ｍｉｎ．で供給した。メタンガスの流速は、熱式流量センサーを用いた流量計（コフロック社製、小型マスフローコントローラーＭｏｄｅｌ　ＥＸ２５０Ｓ　シリーズ）を用いて測定した。この時、電力供給装置から電力を供給し、周波数４ＭＨｚの磁場をコイルに印加して、出力１０ｋＷのプラズマを発生させた。なお、プラズマ発生装置内の圧力は大気圧とした。プラズマの安定後、粉体供給器を作動させ、原料Ｓｉ粉体を４００ｍｇ／ｍｉｎ．の速度で、キャリヤーガスとともに、プラズマ内へ導入した。プラズマ内を通過した後の通過流とともに放出された粉末を収集し、酸素雰囲気下で１時間保持した。得られた粉末を実施例８の粉末とした。単位時間当たりの原料Ｓｉ粉末の供給モル数に対する単位時間当たりの炭素源ガスの供給モル数の比であるＣ／Ｓｉは０．３であった。 (Example 8)
The powder of Example 8 was produced using an apparatus obtained by improving a part of the plasma generator shown in FIG. In the improved apparatus, the cooling gas supply pipes 91 in FIG. 2 are a plurality of supply pipes, a part is a rare gas supply pipe, and the other part is a carbon source gas supply pipe. The distance between the opening of the rare gas supply pipe and the opening of the plasma generator 11 was 150 mm. The distance between the opening of the carbon source gas supply pipe and the opening of the plasma generator 11 was 200 mm. In the plasma generator, argon gas as a process gas was added at 60 L / min. At 5 L / min. As an inner gas. At a flow rate of 3 L / min. Supplied with. From the rare gas supply pipe, argon gas was supplied at 20 L / min. Supplied with. From the carbon source gas supply pipe, 0.096 L / min. Of methane gas is used as the carbon source gas. Supplied with. The flow rate of methane gas was measured using a flow meter using a thermal flow sensor (manufactured by Cofrock, small mass flow controller Model EX250S series). At this time, power was supplied from the power supply device, and a magnetic field with a frequency of 4 MHz was applied to the coil to generate plasma with an output of 10 kW. The pressure in the plasma generator was atmospheric pressure. After the plasma was stabilized, the powder feeder was operated, and the raw material Si powder was added at 400 mg / min. Was introduced into the plasma together with the carrier gas at a rate of The powder released along with the flow after passing through the plasma was collected and held in an oxygen atmosphere for 1 hour. The obtained powder was used as the powder of Example 8. C / Si, which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 0.3.
 (実施例９) 
　炭素源ガスとしてメタンガスを０．２２Ｌ／ｍｉｎ．で、供給した以外は、実施例８の粉末と同様にして実施例９の粉末を製造した。単位時間当たりの原料Ｓｉ粉末の供給モル数に対する単位時間当たりの炭素源ガスの供給モル数の比であるＣ／Ｓｉは０．６９であった。 Example 9
Methane gas is used as the carbon source gas at 0.22 L / min. The powder of Example 9 was produced in the same manner as the powder of Example 8 except that the powder was supplied. C / Si, which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 0.69.
 (実施例１０)
　炭素源ガスとしてメタンガスを０．３３Ｌ／ｍｉｎ．で、供給した以外は実施例８の粉末と同様にして実施例１０の粉末を製造した。単位時間当たりの原料Ｓｉ粉末の供給モル数に対する単位時間当たりの炭素源ガスの供給モル数の比であるＣ／Ｓｉは１．０３であった。 (Example 10)
Methane gas as the carbon source gas is 0.33 L / min. Thus, the powder of Example 10 was produced in the same manner as the powder of Example 8 except that it was supplied. C / Si, which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 1.03.
 (実施例１１)
　炭素源ガスとしてメタンガスを０．８Ｌ／ｍｉｎ．で供給した以外は実施例８の粉末と同様にして実施例１１の粉末を製造した。単位時間当たりの原料Ｓｉ粉末の供給モル数に対する単位時間当たりの炭素源ガスの供給モル数の比であるＣ／Ｓｉは２．５であった。 Example 11
Methane gas is used as a carbon source gas at 0.8 L / min. The powder of Example 11 was produced in the same manner as the powder of Example 8 except that the powder was supplied in step VII. C / Si, which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 2.5.
 (実施例１２)
　炭素源ガスとしてメタンガスを０．９６Ｌ／ｍｉｎ．で供給した以外は実施例８の粉末と同様にして実施例１２の粉末を製造した。単位時間当たりの原料Ｓｉ粉末の供給モル数に対する単位時間当たりの炭素源ガスの供給モル数の比であるＣ／Ｓｉは３．０であった。 (Example 12)
Methane gas is used as the carbon source gas at 0.96 L / min. A powder of Example 12 was produced in the same manner as the powder of Example 8 except that the powder was supplied in step VII. C / Si, which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 3.0.
 (実施例１３)
　炭素源ガスとしてメタンガスを１．２４Ｌ／ｍｉｎ．で供給した以外は実施例８の粉末と同様にして実施例１３の粉末を製造した。単位時間当たりの原料Ｓｉ粉末の供給モル数に対する単位時間当たりの炭素源ガスの供給モル数の比であるＣ／Ｓｉは３．８７であった。 (Example 13)
Methane gas is used as a carbon source gas at 1.24 L / min. The powder of Example 13 was produced in the same manner as the powder of Example 8 except that the powder was supplied in step VII. C / Si, which is the ratio of the number of moles of carbon source gas supplied per unit time to the number of moles of raw material Si powder supplied per unit time, was 3.87.
 (実施例１４)
　原料Ｓｉ粉体を１００ｍｇ／ｍｉｎ．の速度で、キャリヤーガスとともに、プラズマ内へ導入したこと、及び炭素源ガスとしてメタンガスを０．０８Ｌ／ｍｉｎ．で供給したこと以外は、実施例８の粉末と同様にして、実施例１４の粉末を製造した。単位時間当たりの原料Ｓｉ粉末の供給モル数に対する単位時間当たりの炭素源ガスの供給モル数の比であるＣ／Ｓｉは１．０であった。 (Example 14)
The raw material Si powder was 100 mg / min. The methane gas was introduced into the plasma together with the carrier gas at a rate of 0.08 L / min. A powder of Example 14 was produced in the same manner as the powder of Example 8, except that the powder was supplied in step VII. C / Si, which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 1.0.
 (実施例１５)
　原料Ｓｉ粉体を７００ｍｇ／ｍｉｎ．の速度で、キャリヤーガスとともに、プラズマ内へ導入したこと、及び炭素源ガスとしてメタンガスを０．５６Ｌ／ｍｉｎ．で供給したこと以外は、実施例１４の粉末と同様にして、実施例１５の粉末を製造した。単位時間当たりの原料Ｓｉ粉末の供給モル数に対する単位時間当たりの炭素源ガスの供給モル数の比であるＣ／Ｓｉは１．０であった。 (Example 15)
The raw material Si powder was 700 mg / min. The methane gas was introduced into the plasma together with the carrier gas at a rate of 0.56 L / min. The powder of Example 15 was produced in the same manner as the powder of Example 14, except that the powder was supplied in step S2. C / Si, which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 1.0.
 (実施例１６)
　プラズマ出力を１５ｋＷとしたこと、炭素源ガス供給管の開口とプラズマ発生装置内の開口との距離を３５０ｍｍとしたこと、及び炭素源ガスとしてメタンガスを０．３２Ｌ／ｍｉｎ．で供給したこと以外は、実施例８の粉末と同様にして、実施例１６の粉末を製造した。単位時間当たりの原料Ｓｉ粉末の供給モル数に対する単位時間当たりの炭素源ガスの供給モル数の比であるＣ／Ｓｉは１．０であった。 (Example 16)
The plasma output was 15 kW, the distance between the opening of the carbon source gas supply pipe and the opening in the plasma generator was 350 mm, and methane gas as the carbon source gas was 0.32 L / min. A powder of Example 16 was produced in the same manner as the powder of Example 8, except that the powder was supplied in (4). C / Si, which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 1.0.
 (実施例１７)
　プラズマ出力を２０ｋＷとしたこと以外は、実施例１６の粉末と同様にして、実施例１７の粉末を製造した。単位時間当たりの原料Ｓｉ粉末の供給モル数に対する単位時間当たりの炭素源ガスの供給モル数の比であるＣ／Ｓｉは１．０であった。 (Example 17)
A powder of Example 17 was produced in the same manner as the powder of Example 16, except that the plasma output was 20 kW. C / Si, which is the ratio of the number of moles of carbon source gas fed per unit time to the number of moles of raw material Si powder fed per unit time, was 1.0.
（ＴＥＭ観察結果）
　実施例８～１７の粉末のＴＥＭ観察を行なった。実施例８～１７の粉末のいずれにおいても、複数のＳｉ粒子と複数の繊維状Ｓｉの組み合わせのＳｉ粒子結合体、及び、Ｓｉ粒子一個とそのＳｉ粒子に結合する繊維状Ｓｉ一個の組み合わせのＳｉ粒子結合体が多く観察された。 (TEM observation result)
TEM observation of the powders of Examples 8 to 17 was performed. In any of the powders of Examples 8 to 17, a Si particle combination of a combination of a plurality of Si particles and a plurality of fibrous Si, and a combination of one Si particle and one fibrous Si bonded to the Si particle. Many particle combinations were observed.
（被膜の解析１－２）
　被膜の解析１－１と同様にして、実施例８～実施例１７の粉末の被膜について、ラマン分光装置を用いて、ラマンスペクトルを測定した。得られた実施例８～１７の粉末の被膜のラマン分光法によるラマンスペクトルには、１５９０ｃｍ－１付近に見られるＧバンドと１３５０ｃｍ－１付近に見られるＤバンドの両方のピークが観察された。このことから、実施例８～１７の粉末の被膜にはグラファイトとアモルファスカーボンが含まれることが確認できた。また、実施例８～１７の粉末の被膜のラマンスペクトルには、さらに、１２３０ｃｍ－１～１２７０ｃｍ－１、１４２０ｃｍ－１～１４８０ｃｍ－１の範囲にピークが観察された。実施例８～１７の粉末の被膜にはＨ元素が残っており、ＣＨ２及び／又はＣＨ３に由来する構造を有していることが確認された。 (Coating analysis 1-2)
In the same manner as in coating analysis 1-1, Raman spectra of the powder coatings of Examples 8 to 17 were measured using a Raman spectrometer. Raman spectra by obtained in Examples 8 to Raman spectroscopy of the powder coating 17, the peak of both D band observed around G band and 1350 cm -1 observed around 1590 cm -1 were observed. From this, it was confirmed that the powder coatings of Examples 8 to 17 contained graphite and amorphous carbon. Further, in the Raman spectrum of the film of the powder of Example 8-17, further, 1230 cm -1 ~ 1270 cm -1, a peak was observed in the range of 1420cm -1 ~ 1480cm -1. In the powder coatings of Examples 8 to 17, H element remained, and it was confirmed that the powder had a structure derived from CH 2 and / or CH 3 .
　プラズマ出力１５ｋＷで製造された実施例１６の粉末及びプラズマ出力２０ｋＷで製造された実施例１７の粉末において、被膜がＣＨ２及び／又はＣＨ３に由来する構造を有するメカニズムとしては、以下のことが考えられる。比較例１及び比較例２の粉末の製造時では、冷却ガス供給管の開口とプラズマ発生装置内の開口との距離を２００ｍｍとしたのに対して、実施例１６及び１７の粉末の製造時において、希ガス供給管の開口とプラズマ発生装置内の開口との距離を１５０ｍｍとし、炭素源ガス供給管の開口とプラズマ発生装置内の開口との距離を３５０ｍｍとした。実施例１６及び１７の粉末の製造時において、比較例１及び比較例２の粉末の製造時と比べて、希ガス供給管の開口を高くし、炭素源ガス供給管の開口を低くしたため、プラズマ出力が１５ｋＷ及び２０ｋＷであっても、炭素源ガスに含まれるＣＨ４は、Ｃ単体までは分解されずに、Ｈが残った状態でＳｉ表面を被覆したと推測される。 In the powder of Example 16 manufactured at a plasma power of 15 kW and the powder of Example 17 manufactured at a plasma power of 20 kW, the mechanism having a structure derived from CH 2 and / or CH 3 is as follows. Conceivable. In the production of the powders of Comparative Examples 1 and 2, the distance between the opening of the cooling gas supply pipe and the opening in the plasma generator was 200 mm, whereas in the production of the powders of Examples 16 and 17, The distance between the opening of the rare gas supply pipe and the opening in the plasma generator was 150 mm, and the distance between the opening of the carbon source gas supply pipe and the opening in the plasma generator was 350 mm. Since the opening of the rare gas supply pipe was made higher and the opening of the carbon source gas supply pipe was made lower in the production of the powders of Examples 16 and 17 than in the production of the powders of Comparative Examples 1 and 2. Even if the output is 15 kW and 20 kW, it is presumed that CH 4 contained in the carbon source gas covered the Si surface with H remaining without being decomposed to C alone.
（Ｓｉ結晶及びＳｉＣの確認２）
　実施例８～１７の粉末をＸＲＤ装置で測定した。実施例８～１７の粉末にはいずれもＳｉ結晶のピークが観察された。実施例８～１７の粉末にはＳｉ結晶が存在することがわかった。また、実施例１３及び実施例１７の粉末にはＳｉＣが存在することがわかった。実施例８～１２、１４～１６の粉末では、ＳｉＣの存在はほとんど確認できなかった。実施例１３の粉末の製造方法においては、炭素源ガスの流速が速く、実施例１７の粉末の製造方法においては、プラズマ出力が高いため、ＳｉＣが発生したものと考えられる。実施例１３及び実施例１７の粉末の製造方法においても、さらに炭素源ガス供給管の開口とプラズマ発生装置内の開口との距離を大きくすることによって、ＳｉＣの発生は抑制されると推測される。 (Confirmation of Si crystal and SiC 2)
The powders of Examples 8 to 17 were measured with an XRD apparatus. In each of the powders of Examples 8 to 17, a Si crystal peak was observed. It was found that Si crystals were present in the powders of Examples 8 to 17. Moreover, it turned out that SiC exists in the powder of Example 13 and Example 17. In the powders of Examples 8 to 12 and 14 to 16, the presence of SiC was hardly confirmed. In the powder production method of Example 13, the flow rate of the carbon source gas is high, and in the powder production method of Example 17, the plasma output is high, so it is considered that SiC was generated. In the powder production methods of Example 13 and Example 17, it is speculated that generation of SiC is suppressed by further increasing the distance between the opening of the carbon source gas supply pipe and the opening in the plasma generator. .
　１：粉体供給器、２：電力供給装置、３：排気部、４：フィルター、５：内部チャンバー、６：キャリヤーガス経路、７：プロセスガス経路、８：インナーガス経路、９：冷却ガス経路、１０：Ｓｉ粒子、１１：プラズマ発生装置内、２０：繊維状Ｓｉ、３０：空隙、４０：Ｓｉ粒子結合体、５０：結合部、６０：被膜、９１：冷却ガス供給管。 1: powder feeder, 2: power supply device, 3: exhaust unit, 4: filter, 5: internal chamber, 6: carrier gas path, 7: process gas path, 8: inner gas path, 9: cooling gas path 10: Si particles, 11: In the plasma generator, 20: Fibrous Si, 30: Gaps, 40: Si particle bonded body, 50: Bonded part, 60: Coating, 91: Cooling gas supply pipe.

Claims (19)

  1. 　Ｓｉ粒子と、該Ｓｉ粒子に結合する繊維状Ｓｉと、を有し、
    　該Ｓｉ粒子の粒径は、該繊維状Ｓｉの繊維径よりも大きいことを特徴とするＳｉ粒子結合体。     Si particles and fibrous Si bonded to the Si particles,
    A Si particle bonded body characterized in that the particle size of the Si particles is larger than the fiber diameter of the fibrous Si.
  2. 　前記繊維状Ｓｉは、複数の前記Ｓｉ粒子に結合する請求項１に記載のＳｉ粒子結合体。 2. The Si particle bonded body according to claim 1, wherein the fibrous Si is bonded to a plurality of the Si particles.
  3. 　複数の前記Ｓｉ粒子と、複数の前記繊維状Ｓｉと、を有する請求項１又は２に記載のＳｉ粒子結合体。 The Si particle combination according to claim 1 or 2, comprising a plurality of the Si particles and a plurality of the fibrous Si.
  4. 　前記Ｓｉ粒子の粒径が１０ｎｍ以上１５００ｎｍ以下である請求項１又は２に記載のＳｉ粒子結合体。 The Si particle combination according to claim 1 or 2, wherein the Si particles have a particle size of 10 nm to 1500 nm.
  5. 　前記繊維状Ｓｉの繊維径は５ｎｍ以上２０ｎｍ以下である請求項１～３のいずれか一項に記載のＳｉ粒子結合体。 The Si particle bonded body according to any one of claims 1 to 3, wherein a fiber diameter of the fibrous Si is 5 nm or more and 20 nm or less.
  6. 　前記Ｓｉ粒子結合体は、Ｓｉ結晶を含む請求項１～５のいずれか一項に記載のＳｉ粒子結合体。 The Si particle bonded body according to any one of claims 1 to 5, wherein the Si particle bonded body includes Si crystal.
  7. 　前記Ｓｉ粒子結合体は空隙を有する請求項１～６のいずれか一項に記載のＳｉ粒子結合体。 The Si particle bonded body according to any one of claims 1 to 6, wherein the Si particle bonded body has voids.
  8. 　請求項１～７のいずれか一項に記載のＳｉ粒子結合体と、
    　前記Ｓｉ粒子結合体の表面に配置された炭素含有被膜と、
    　を有する被膜付きＳｉ粒子結合体。     The Si particle combination according to any one of claims 1 to 7,
    A carbon-containing coating disposed on the surface of the Si particle combination;
    A coated Si particle assembly having:
  9. 　前記炭素含有被膜は、ラマン分光法のラマンスペクトルにおいて、１４２０ｃｍ－１～１４８０ｃｍ－１の範囲にピークトップを有する請求項８に記載の被膜付きＳｉ粒子結合体。 The carbon-containing coating, in the Raman spectrum of the Raman spectroscopy, a coated Si particles conjugate according to claim 8 having a peak top in the range of 1420cm -1 ~ 1480cm -1.
  10. 　酸素含有量が１０％以下である請求項８又は９に記載の被膜付きＳｉ粒子結合体。 The coated Si particle assembly according to claim 8 or 9, wherein the oxygen content is 10% or less.
  11. 　請求項１～７のいずれか一項に記載のＳｉ粒子結合体の製造方法であって、
    　原料Ｓｉ粉末を導入流にて、プラズマ出力が５ｋW以上１５ｋW未満であるプラズマ内に導入する工程と、
    　前記導入流がプラズマ内を通過した後の通過流を該通過流に対向する冷却ガス流で冷却する冷却工程と、
    　を含むことを特徴とするＳｉ粒子結合体の製造方法。     A method for producing a bonded Si particle according to any one of claims 1 to 7,
    Introducing a raw material Si powder into a plasma having a plasma output of 5 kW or more and less than 15 kW by an introduction flow;
    A cooling step of cooling the passing flow after the introduced flow has passed through the plasma with a cooling gas flow facing the passing flow;
    The manufacturing method of the Si particle | grain coupling body characterized by including this.
  12. 　請求項８～１０のいずれか一項に記載の被膜付きＳｉ粒子結合体の製造方法であって、
    　原料Ｓｉ粉末を導入流にて、プラズマ出力が５ｋW以上１５ｋW未満であるプラズマ内に導入する工程と、
    　前記導入流がプラズマ内を通過した後の通過流を該通過流に対向する炭素源ガスを含む冷却ガス流で冷却し、前記通過流内のＳｉを前記炭素源ガスと接触させてＳｉに炭素含有被膜を形成させる冷却工程と、
    　を含むことを特徴とする被膜付きＳｉ粒子結合体の製造方法。     A method for producing a coated Si particle assembly according to any one of claims 8 to 10,
    Introducing a raw material Si powder into a plasma having a plasma output of 5 kW or more and less than 15 kW by an introduction flow;
    The flow after the introduction flow passes through the plasma is cooled with a cooling gas flow containing a carbon source gas facing the flow, and Si in the flow is brought into contact with the carbon source gas to form carbon into Si. A cooling step for forming a coating film,
    The manufacturing method of the Si particle | grain combination body with a film characterized by including this.
  13. 　前記冷却工程の後で、酸素含有雰囲気下、前記炭素含有被膜に酸素を導入する酸素導入工程を含む請求項１２に記載の被膜付きＳｉ粒子結合体の製造方法。 The method for producing a coated Si particle combination according to claim 12, further comprising an oxygen introducing step of introducing oxygen into the carbon-containing coating in an oxygen-containing atmosphere after the cooling step.
  14. 　請求項１～７のいずれか一項に記載のＳｉ粒子結合体又は請求項８～１０のいずれか一項に記載の被膜付きＳｉ粒子結合体を具備する負極。 A negative electrode comprising the Si particle bonded body according to any one of claims 1 to 7 or the coated Si particle bonded body according to any one of claims 8 to 10.
  15. 　請求項１４に記載の負極を具備する非水電解質二次電池。 A non-aqueous electrolyte secondary battery comprising the negative electrode according to claim 14.
  16. 　Ｓｉ粒子と、
    　該Ｓｉ粒子の表面に配置され、Ｃ、Ｈ、Ｏを含む炭素含有被膜と、を有し、
    　該炭素含有被膜は、熱分解ガスクロマトグラフ質量分析において、テルペン類のフラグメントが検出されることを特徴とする負極活物質。     Si particles,
    A carbon-containing film that is disposed on the surface of the Si particles and contains C, H, and O,
    The carbon-containing film is a negative electrode active material, wherein fragments of terpenes are detected in pyrolysis gas chromatography mass spectrometry.
  17. 　前記炭素含有被膜は、熱分解ガスクロマトグラフ質量分析において、さらにエステル骨格のフラグメントが検出される請求項１６に記載の負極活物質。 The negative electrode active material according to claim 16, wherein the carbon-containing coating further detects a fragment of an ester skeleton in pyrolysis gas chromatography mass spectrometry.
  18. 　請求項１６又は１７に記載の負極活物質を具備する非水電解質二次電池。 A nonaqueous electrolyte secondary battery comprising the negative electrode active material according to claim 16 or 17.
  19. 　請求項８～１０のいずれか一項に記載の被膜付きＳｉ粒子結合体の製造方法であって、
    　原料Ｓｉ粉末を導入流にてプラズマ内に導入する工程と、
    　前記導入流がプラズマ内を通過した後の通過流を該通過流に対向する炭素源ガスを含む冷却ガス流で冷却し、前記通過流内のＳｉを前記炭素源ガスと接触させてＳｉに炭素含有被膜を形成させる冷却工程と、
    　を含み、
    前記冷却工程において、前記冷却ガス流は、前記炭素源ガス及び希ガスを含み、前記炭素源ガスの供給位置は、前記希ガスの供給位置よりも、前記通過流の通過方向に対して下流であることを特徴とする被膜付きＳｉ粒子結合体の製造方法。     A method for producing a coated Si particle assembly according to any one of claims 8 to 10,
    Introducing the raw material Si powder into the plasma by an introduction flow;
    The flow after the introduction flow passes through the plasma is cooled with a cooling gas flow containing a carbon source gas facing the flow, and Si in the flow is brought into contact with the carbon source gas to form carbon into Si. A cooling step for forming a coating film,
    Including
    In the cooling step, the cooling gas flow includes the carbon source gas and a rare gas, and the supply position of the carbon source gas is more downstream than the supply position of the rare gas with respect to the passage direction of the passage flow. A method for producing a coated Si particle composite body characterized by being.
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