WO2020230657A1 - Oxide-based solid-state electrolyte - Google Patents

Oxide-based solid-state electrolyte Download PDF

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Publication number
WO2020230657A1
WO2020230657A1 PCT/JP2020/018343 JP2020018343W WO2020230657A1 WO 2020230657 A1 WO2020230657 A1 WO 2020230657A1 JP 2020018343 W JP2020018343 W JP 2020018343W WO 2020230657 A1 WO2020230657 A1 WO 2020230657A1
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solid electrolyte
oxide
based solid
particles
particle size
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PCT/JP2020/018343
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French (fr)
Japanese (ja)
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英樹 堺
一元 西島
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東邦チタニウム株式会社
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Priority to JP2021519375A priority Critical patent/JPWO2020230657A1/ja
Publication of WO2020230657A1 publication Critical patent/WO2020230657A1/en

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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G23/00—Compounds of titanium
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/06—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/06—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances
    • H01B1/08—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances oxides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0561—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of inorganic materials only
    • H01M10/0562—Solid materials
    • 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 an oxide-based solid electrolyte suitable for use in, for example, a firing type solid electrolyte of a secondary battery, and in particular, enables low-temperature sintering of the oxide-based solid electrolyte during the production of an all-solid-state battery or the like. It proposes the technology to make it.
  • all-solid-state batteries such as all-solid-state lithium-ion batteries in which the electrolyte is a solid have excellent stability, reliability, and high energy density as compared with lithium-ion batteries using a liquid electrolyte.
  • high output and a wide operating temperature can be realized. Therefore, all-solid-state batteries are expected to be put into practical use in various applications such as automobiles, electronic devices, and household storage batteries.
  • This all-solid-state battery is generally classified into a thin film type manufactured by the vapor phase method and a bulk type manufactured by sintering fine particles.
  • the bulk type all-solid-state battery particles of the positive electrode active material, the solid electrolyte, and the negative electrode active material are laminated in layers between the current collectors, and these particles are sintered by heating at a predetermined temperature. Is formed.
  • the solid electrolyte of a bulk type all-solid-state battery is sometimes referred to as a fire-type solid electrolyte because it is obtained by sintering solid electrolyte particles.
  • Patent Documents describing this type of oxide-based solid electrolyte include, for example, Patent Documents 1 and 2.
  • Patent Document 1 states that "a secondary battery includes a positive electrode, a negative electrode, and a solid electrolyte layer interposed between the positive electrode and the negative electrode, and the positive electrode and the negative electrode are solid electrolyte particles.
  • the solid electrolyte layer contains only the second solid electrolyte particles as the solid electrolyte particles, and the average particle size of the second solid electrolyte particles is the first solid.
  • the average particle size of the first solid electrolyte particles is larger than the average particle size of the electrolyte particles, the average particle size of the first solid electrolyte particles is 1 nm to 100 nm, and the average particle size of the second solid electrolyte particles is 2 ⁇ m to 10 ⁇ m.
  • the first solid electrolyte particles and the second solid electrolyte particles are composite oxides represented by the following chemical formula (1), and Li 3x La (2 / 3-x) TiO 3 (0 ⁇ x ⁇ 0.16) chemical formula.
  • the ratio of the secondary phase in the first solid electrolyte particles is 0.1% by weight to 5% by weight with respect to the total weight of the first solid electrolyte particles, and is in the second solid electrolyte particles.
  • a secondary battery wherein the ratio of the secondary phase is 0.1% by weight to 5% by weight based on the total weight of the second solid electrolyte particles.
  • the specific surface area (BET) of the first solid electrolyte particles is 100 m 2 / g to 400 m 2 / g
  • the specific surface area (BET) of the second solid electrolyte particles is 10 m 2 / g. From 50 m 2 / g.
  • Patent Document 2 states that "a method for producing solid electrolyte particles represented by the following chemical formula (1), which is Li 3x La (2 / 3-x) TiO 3 (0 ⁇ x ⁇ 0.16) (1). ) A step of mixing a titanium precursor, a lanthanum precursor, and a lithium precursor under an aqueous solvent or an organic solvent to produce a precursor solution, and a step of heat-treating the precursor solution are included.
  • the precursor comprises titanium oxide particles having an average particle size (D 50 ) of 0.5 nm to 10 nm, and the solid electrolyte particles having an average particle size (D 50 ) of 20 nm to 100 nm.
  • a characteristic method for producing solid electrolyte particles "has been proposed.
  • Patent Document 2 states that "according to one embodiment of the present invention, the specific surface area of the solid electrolyte particles forming the solid electrolyte layer is preferably 200 m 2 / g to 400 m 2 / g.”
  • the oxide-based solid electrolyte or the like used for forming the firing-type solid electrolyte as described above is required to be capable of exhibiting a predetermined high ionic conductivity by sintering with heating at a relatively low temperature. This means that in an oxide-based solid electrolyte that cannot be sintered unless it is heated to a high temperature, the positive electrode active material is placed between the positive electrode active material and the negative electrode active material and heated to the high temperature for sintering. This is because there is a possibility that a reaction may occur with the active material of the negative electrode or the negative electrode, and a substance capable of lowering the ionic conductivity may be generated at the interface between them.
  • oxide-based solid electrolytes of A 2 / 3-x Li 3x TiO 3 (0 ⁇ x ⁇ 0.16, A: one or more elements selected from lanthanoids) have been heated to a certain high temperature. Without it, it would not be sintered. Therefore, in order to use such an oxide-based solid electrolyte for, for example, forming a calcined solid electrolyte, improvement is required in this respect.
  • Such low-temperature sintering could not be realized with the oxide-based solid electrolyte particles described in Patent Documents 1 and 2.
  • the oxide-based solid electrolyte particles of Patent Documents 1 and 2 are not used for the firing type solid electrolyte, but form the solid electrolyte by screen printing and drying. Therefore, low-temperature sintering as described above is performed in the first place. Is not required.
  • the present invention has an object of solving such a problem, and an object of the present invention is to provide an oxide-based solid electrolyte that can be sintered at a relatively low temperature.
  • the inventor has newly found that the sintering temperature of an oxide-based solid electrolyte having a predetermined particle size and a predetermined specific surface area is significantly lowered.
  • the oxide-based solid electrolyte of the present invention has the following general formula (I).
  • a 2 / 3-x Li 3x TiO 3 (I) (In the formula, x satisfies 0.04 ⁇ x ⁇ 0.14, and A is one or more elements selected from lanthanoids.)
  • a in the compound represented by the general formula (I) A 2 / 3-x Li 3x TiO 3 can be La.
  • the oxide-based solid electrolyte of the present invention preferably has a sintering start temperature of 900 ° C. or lower.
  • the oxide-based solid electrolyte of the present invention can be sintered at a relatively low temperature.
  • the oxide-based solid electrolyte can be suitably used as a fired solid electrolyte for a secondary battery including an all-solid-state battery.
  • FIG. It is a graph which shows the X-ray diffraction pattern of the comparative example 1.
  • FIG. It is a graph which shows the X-ray diffraction pattern of the comparative example 2.
  • FIG. It is a graph which shows the X-ray diffraction pattern of Example 2.
  • 6 is an SEM image of the solid electrolyte particles of Example 1.
  • 6 is an SEM image of the solid electrolyte particles of Example 2.
  • the oxide-based solid electrolyte according to the embodiment of the present invention is, for example, a particulate or powder used for a calcined solid electrolyte of a secondary battery, and has the following general formula (I).
  • a 2 / 3-x Li 3x TiO 3 (I) (In the formula, x satisfies 0.04 ⁇ x ⁇ 0.14, and A is one or more elements selected from lanthanoids.)
  • a in the general formula (I) is lanthanum (La), cerium (Ce), placeodim (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium.
  • the oxide-based solid electrolyte of one embodiment of the invention the average particle size D50 0.1 [mu] m ⁇ 1.0 .mu.m, BET specific surface area in the 5.0m 2 /g ⁇ 100.0m 2 / g is there.
  • the oxide-based solid electrolyte contains a compound represented by the above general formula (I). More specifically, this compound may be a composite oxide such as LLTO.
  • the oxide-based solid electrolyte preferably contains a compound of La 2 / 3-x Li 3x TiO 3 (0.04 ⁇ x ⁇ 0.14) in which A in the general formula (I) is La. Is.
  • La x Li 2-3x TiO 3-a La 0.5 K represented by the general formula (Ib).
  • La x represented by (I-c) Li 2-3x Ti 1-a M a O 3-a, or, Sr x-1.5a of the general formula (I-d) La a Li 1.5-2x Ti 0.5 Ta 0.5 O 3
  • x satisfies 0.55 ⁇ x ⁇ 0.59, and a is 0 ⁇ a ⁇ . It satisfies 0.2, and M is at least one selected from Al, Fe, and Ga.
  • the Al 2 O 3 content is 0.35% by weight or less, and the SiO 2 content is Examples thereof include those having a weight of 0.1% by weight or less.
  • the oxide-based solid electrolyte contains the compound represented by the above general formula (I).
  • the X-ray diffraction pattern of the oxide-based solid electrolyte obtained by PANalytical X'pert Pro is collated with the ICDD database (PANalytical Exclusive Database and PDF-4 + 2019RDB), and the oxide-based solid electrolyte is collated.
  • the compound represented by the above general formula (I) contained therein is identified.
  • the X-ray diffraction pattern of the oxide-based solid electrolyte obtained by the powder X-ray diffraction method and from which noise has been removed is collated with the above ICDD database, and the above general formula is included in the X-ray diffraction pattern of the oxide-based solid electrolyte.
  • the oxide-based solid electrolyte contains the compound represented by the above general formula (I).
  • the compound represented by the above general formula (I) in the oxide-based solid electrolyte when a part of oxygen is replaced with another element such as F or Cl, or a part of the transition metal is Fe, It may be replaced with other metals such as Cr, Ti, Nb, W, Mo, Na, K, Mg and Ca.
  • Li and oxygen may be excessive or deficient with respect to the stoichiometric composition of the compound represented by the general formula (I). Further, the crystal structure of the compound represented by the above general formula (I) in the oxide-based solid electrolyte may be distorted.
  • the peak is obtained from the X-ray diffraction pattern of the compound represented by the general formula (I). May shift (peak shift).
  • the compound represented by the general formula (I) is preferably contained in an oxide-based solid electrolyte in an amount of 99.0% by mass or more, and even more preferably 99.5% by mass or more. Since the higher the content of this compound is, the more desirable it is, there is no particular preferable upper limit value thereof, but for example, it may be 99.999% by mass or less, typically 99.99% by mass or less.
  • the content of the compound is measured by ICP (Inductively Coupled Plasma).
  • the oxide-based solid electrolyte may contain at least one selected from the group consisting of Si, Al and Fe as impurities in addition to the compound represented by the above general formula (I).
  • the content of impurities in the oxide-based solid electrolyte is preferably 1.0% by mass or less, more preferably 0.5% by mass or less.
  • a solid electrolyte is recognized as a solid capable of moving ions (charged substances) by an electric field applied from the outside.
  • electric power can be extracted from the solid electrolyte by utilizing the movement of ions.
  • a solid electrolyte oxide-based solid electrolyte
  • the oxide-based solid electrolyte of the embodiment of the present invention can be used as a power generation material for a secondary battery or an electrode conductor of an electrolytic capacitor, and may also be applied to various solid electrolyte devices such as gas sensors and gas separation / manufacturing. Be done.
  • an oxide-based solid electrolyte containing the compound represented by the above general formula (I) when applied to a power generation material of a secondary battery, for example, lithium ions measured at 27 ° C. It is preferable that the conductivity is, for example, 5 ⁇ 10 -4 Scm -1 or more, and further preferably 6 ⁇ 10 -4 Scm -1 or more.
  • the impedance method is used to measure the lithium ion conductivity of the oxide-based solid electrolyte. An example of measuring the lithium ion conductivity of the oxide-based solid electrolyte by the impedance method is as shown below.
  • a 1 M aqueous solution of LiCl is impregnated into two 10 mm square filter papers and attached to both sides of a plate of an oxide-based solid electrolyte containing a compound represented by the above general formula (I) having a thickness of 2 mm.
  • the oxide-based solid electrolyte containing the compound represented by the general formula (I) is prepared in a size of 14 mm square, and the filter paper is prepared in a size of 10 mm square. This is sandwiched between electrodes made of stainless steel.
  • the LiCl aqueous solution soaked in the filter paper is used as the electrolyte.
  • the ionic conductivity is in the frequency range of 5 Hz up to 13 MHz, and the LCR meter (Huled Packard Co., Ltd.) It is measured by the AC impedance method using HP4192A).
  • the average particle size D50 of the powdered oxide-based solid electrolyte is 0.1 ⁇ m to 1.0 ⁇ m. If the average particle size D50 is within this range and the BET specific surface area is within a predetermined range as described later, the particles will start to solidify and be baked by heating at a relatively low temperature of, for example, 1000 ° C. or lower. The conclusion is started. This temperature may be referred to as "sintering start temperature" in the present specification. This is thought to be due to the movement of atoms at high temperatures, but is not limited to such a theory. The composite oxide particles contained in the conventional oxide-based solid electrolyte did not start sintering unless they were heated to a high temperature of 1400 ° C. or higher.
  • the sintering start temperature may be lowered to 1000 ° C. or lower, preferably 900 ° C. or lower, more preferably 200 ° C. to 900 ° C. ..
  • a low sintering temperature can be realized by the above-mentioned average particle size D50 of the oxide-based solid electrolyte, the BET specific surface area described later, and the like.
  • the sintering start temperature can be determined based on a thermomechanical analyzer (TMA).
  • thermomechanical analyzer An example of measuring the sintering start temperature of the oxide-based solid electrolyte using a thermomechanical analyzer (TMA) is as shown below.
  • 0.5 g of an oxide-based solid electrolyte is subjected to uniaxial compression of 40 MPa to prepare a green compact.
  • the green compact is placed in a cold isotropic pressurizing device, and cold isotropic pressurization (CIP) is performed on the green compact at a pressure of 200 MPa.
  • CIP cold isotropic pressurization
  • a columnar molded body having a diameter of 5 mm and a length of 10 mm is obtained.
  • the sintering start temperature of this molded product is measured by a thermomechanical analyzer (TMA).
  • the sintering start temperature is the particles that are in contact with each other (mutual contact particles) when the molded body of the oxide-based solid electrolyte is heated at 5 ° C./min in the air using a thermomechanical analyzer (TMA). ) Means the temperature at which the shrinkage rate reaches 0.1%. Normally, the sintering of particles proceeds by the consumption of particles before sintering and the growth of joints between particles, and at the same time, shrinkage occurs. That is, the shrinkage rate referred to here is the length L 1 of the mutual contact particles before sintering and the length L 1 of the mutual contact particles before sintering with respect to the length L 1 of the mutual contact particles before sintering when a plurality of particles are sintered.
  • the temperature at which the shrinkage rate becomes 0.1% at the time of measurement by TMA is defined as the sintering start temperature.
  • the average particle size D50 of the oxide-based solid electrolyte relatively small in this way, the density at the time of sintering can be increased. As a result, the ionic conductivity is improved, and it can be suitably used for a calcined solid electrolyte of an all-solid-state battery.
  • the average particle size D50 exceeds 1.0 ⁇ m, it may be difficult to realize such low temperature sintering. On the other hand, when the average particle size D50 is less than 0.1 ⁇ m, the particles become too fine and easily aggregate, which causes inconvenience in terms of handleability. From this viewpoint, the average particle size D50 of the oxide-based solid electrolyte is more preferably 0.1 ⁇ m to 0.9 ⁇ m.
  • the average particle size D50 of the oxide-based solid electrolyte refers to the particle size at which the cumulative distribution on a volume basis is 50% in the particle size distribution measurement obtained by the laser diffraction / scattering method, and is measured based on JIS Z8825: 2013.
  • BET specific surface area of the oxide-based solid electrolyte BET specific surface area of the oxide-based solid electrolyte, and 5.0m 2 /g ⁇ 100.0m 2 / g.
  • the BET specific surface area By adjusting the BET specific surface area so as to be within this range together with the average particle size D50 described above, sintering at a low temperature becomes possible as described above.
  • the BET specific surface area is less than 5.0 m 2 / g, the sintering temperature does not drop sufficiently.
  • the BET specific surface area is larger than 100.0 m 2 / g, inconvenience such as deterioration of handleability occurs. Therefore, BET specific surface area, it is more preferable to further 5.0m 2 /g ⁇ 50.0m 2 / g.
  • the BET specific surface area of the oxide-based solid electrolyte is measured by the BET method.
  • the above-mentioned oxide-based solid electrolyte has a density of a sintered body obtained by sintering a molded body obtained by subjecting it to cold isotropic pressure (CIP) at a pressure of 200 MPa (sintered body). density), it is preferable to be 4.50g / cm 3 ⁇ 5.23g / cm 3. In this case, the sintering when forming the calcined solid electrolyte promotes the grain growth of the oxide-based solid electrolyte, and the ionic conductivity is further improved.
  • CIP cold isotropic pressure
  • Sintered density it is more preferably 4.90g / cm 3 ⁇ 5.23g / cm 3. If the sintered body density is too low, the ionic conductivity may decrease.
  • the sintered body density is measured as follows. First, 0.5 g of an oxide-based solid electrolyte is subjected to uniaxial compression of 40 MPa to prepare a green compact. Next, this green compact is placed in a cold isotropic pressurizing device, and cold isotropic pressurization is performed on the green compact at a pressure of 200 MPa. As a result, a columnar molded body having a diameter of 5 mm and a length of 10 mm is obtained. Then, the obtained molded product is sintered to obtain a sintered body. Then, the density of the sintered body is measured by the size and weight of the sintered body.
  • the sintering temperature may be 1000 ° C. or lower, preferably 900 ° C. or lower, more preferably 200 ° C. to 900 ° C.
  • the raw material preparation step for example, the raw material preparation step, the first wet pulverization step, the calcining step, the second wet pulverization step, the dry pulverization step and the pulverization step are performed in this order. be able to. More details are as follows.
  • lithium compounds such as lithium hydroxide and lithium carbonate
  • titanium compounds such as titanium oxide, metatitanium acid, and orthotitanic acid as titanium raw materials
  • lanthanum oxide as lantern raw materials.
  • at least one hydroxide, chloride and / or carbonate selected from the group consisting of Sr, K, Fe, Ga and Ta is also prepared.
  • the average particle size D50 and the BET specific surface area of the oxide-based solid electrolyte to be produced can be easily adjusted within predetermined ranges.
  • the average particle size D50 of the titanium compound such as titanium oxide is preferably 0.1 ⁇ m to 1.0 ⁇ m, and more preferably 0.1 ⁇ m to 0.9 ⁇ m.
  • the titanium compound used as the titanium raw material, BET specific surface area is preferably 5.0m 2 /g ⁇ 100.0m 2 / g, more preferably 5.0m 2 /g ⁇ 50.0m 2 / g.
  • the average particle size D50 and the BET specific surface area of the titanium compound are measured in the same manner as in the method described above for the average particle size D50 and the BET specific surface area of the oxide-based solid electrolyte, respectively.
  • the above-mentioned raw materials such as lithium raw material, titanium raw material and lantern raw material are mixed and pulverized at a predetermined molar ratio by a ball mill or the like.
  • a mixed solvent of pure water and alcohol such as ethanol and a dispersion medium such as a surfactant are added to the ball mill as needed, and the raw materials are pulverized in that state.
  • the lithium raw material may be added in an amount of 0% by weight to 15% by weight more than the amount of lithium having the desired composition in consideration of the volatile matter in the calcining step and the sintering step.
  • the raw materials do not aggregate and are easily dispersed, so that the crushing time can be shortened as compared with the case of pulverizing only with water.
  • a urethane lining ball mill it is preferable to use a urethane lining ball mill, a nylon ball mill, a natural rubber lining ball mill, or the like.
  • a urethane lining ball mill it is preferable to use a urethane lining ball mill, a nylon ball mill, a natural rubber lining ball mill, or the like.
  • mixing of Al 2 O 3 and SiO 2 components when using an alumina lining ball mill is suppressed.
  • the pulverized media zirconia media and alumina media can be used.
  • the first wet pulverization step after pulverization, it is dried using a spray dryer dryer, a fluidized bed dryer, a rolling granulation dryer, a freeze dryer, a hot air dryer, or the like.
  • a spray dryer / dryer for example, the hot air inlet temperature can be set to 200 to 250 ° C. and the exhaust air temperature can be set to 90 to 120 ° C.
  • the first pulverized powder is obtained.
  • the above-mentioned first pulverized powder is sieved with a sieve having a predetermined opening as necessary, and then a calcining step of heating at 1000 ° C. to 1200 ° C. for 1 to 12 hours is performed.
  • a calcining step of heating at 1000 ° C. to 1200 ° C. for 1 to 12 hours.
  • an oxygen atmosphere, an air atmosphere, or an inert gas atmosphere such as nitrogen can be created.
  • the sieve can be separated by a sieve having a predetermined opening. By going through the calcination step, the calcination powder is obtained.
  • a second wet pulverization step is performed in which the calcined powder is pulverized by adding a solvent with a ball mill or the like.
  • the second wet pulverization step is also carried out by charging a ball mill with a mixed solvent of pure water and alcohol such as ethanol and, if necessary, a dispersion medium such as a surfactant.
  • a dispersion medium such as a surfactant.
  • an alumina lining ball mill, a urethane lining ball mill, a nylon ball mill, and a natural rubber lining ball mill can be used.
  • the pulverized media zirconia media and alumina media can be used.
  • wet pulverization by a bead mill may be performed.
  • the crushing time can be 1 hour to 6 hours.
  • after pulverization it can be dried in the same manner as in the first wet pulverization step.
  • a second pulverized powder is obtained.
  • the dry crushing step can be performed on the second crushed powder.
  • the second pulverized powder is pulverized by a dry method using a ball mill or the like to obtain a third pulverized powder.
  • a ball mill an alumina lining ball mill, a urethane lining ball mill, a nylon ball mill, a natural rubber lining ball mill and the like can be used, and as the crushing medium, a zirconia media, an alumina media and the like can be used.
  • the crushing time is, for example, 2 hours to 10 hours. However, the dry crushing step may be omitted.
  • a micronization step of micronizing the second pulverized powder or the third pulverized powder can be performed.
  • the second pulverized powder or the third pulverized powder is pulverized or crushed to have a smaller particle size.
  • a dry or wet jet mill, ball mill, bead mill or the like can be used, and among them, the jet mill is preferable in terms of pulverization efficiency.
  • a secondary battery can be manufactured by using the oxide-based solid electrolyte described above.
  • the secondary battery referred to here means a storage battery that is rechargeable and can be used repeatedly, and includes a battery that uses a liquid electrolyte and a battery that uses a solid electrolyte.
  • the above-mentioned oxide-based solid electrolyte may be mixed in for the purpose of improving the positive electrode and the negative electrode.
  • Oxide-based solid electrolytes can typically be suitably used for all-solid-state batteries containing solid electrolytes.
  • the all-solid-state battery is located, for example, between at least a positive electrode layer in which positive electrode active material particles are arranged in layers, a negative electrode layer in which negative electrode active material particles are arranged in layers, and an oxide-based solid. It may have a solid electrolyte layer in which the electrolytes are arranged in layers. Some oxide-based solid electrolytes may be present in the positive electrode layer and the negative electrode layer.
  • an all-solid-state battery further has a current collector provided on the outside of each of the positive electrode layer and the negative electrode layer so as to sandwich the positive electrode layer, the solid electrolyte layer, and the negative electrode layer from both sides.
  • Such an all-solid-state battery is sometimes referred to as a bulk-type all-solid-state battery to distinguish it from a thin-film type all-solid-state battery formed by laminating thin films by a vapor phase method such as a vacuum vapor deposition method.
  • positive electrode active material particles, oxide-based solid electrolyte, and negative electrode active material particles are laminated in layers between current collectors. Then, the positive electrode active material particles, the oxide-based solid electrolyte, and the negative electrode active material particles are heated to a predetermined temperature and sintered. As a result, an all-solid-state battery such as an all-solid-state lithium-ion battery capable of exhibiting the required ionic conductivity can be obtained.
  • the oxide-based solid electrolyte can be sintered and arranged in the positive electrode layer and the negative electrode layer, so that the ion conduction path there is secured and the battery has high conductivity. Become. In this case, the fired solid electrolyte exists not only in the solid electrolyte layer but also in the positive electrode layer and the negative electrode layer.
  • the temperature is high enough to sinter the oxide-based solid electrolyte when manufacturing a bulk-type all-solid-state battery. Needs to be heated.
  • the positive electrode active material particles, the oxide-based solid electrolyte, and the negative electrode active material particles laminated in layers are heated to a high temperature, the positive electrode active material particles and the negative electrode active material particles react with the oxide solid electrolyte, and the positive electrode layer Or, an unintended substance may be generated at the interface between the negative electrode layer and the solid electrolyte layer, which may reduce the ionic conductivity.
  • the oxide-based solid electrolyte of the above-described embodiment enables low-temperature sintering, when used in a bulk-type all-solid-state battery, the ionic conductivity to the interface of each layer is lowered. The production of the obtained substance can be suppressed. Therefore, a bulk type all-solid-state battery having the required battery performance can be effectively manufactured. That is, the oxide-based solid electrolyte of the embodiment described here can be suitably used as a calcined solid electrolyte of an all-solid-state battery.
  • oxide-based solid electrolyte of the present invention was prototyped and its effect was confirmed, which will be described below.
  • the description here is for the purpose of mere illustration, and is not intended to be limited thereto.
  • Example 3 titanium oxide having an average particle size D50 of 2.2 ⁇ m and a BET specific surface area of 2.0 m 2 / g was used.
  • Example 3 titanium oxide having an average particle size D50 of 0.8 ⁇ m and a BET specific surface area of 5.0 m 2 / g was used.
  • Examples 4 to 6 titanium oxide having an average particle size D50 of 2.2 ⁇ m and a BET specific surface area of 2.0 m 2 / g was used.
  • the above raw materials were weighed and put into a urethane lining ball mill (capacity 200 L) together with 35 L of ion-exchanged water, 35 L of ethanol, and 200 kg of alumina media (diameter 3 mm). Then, after pulverizing for 30 minutes, it was left in the ball mill for 15 hours, and then pulverized again for 30 minutes. After this pulverization, it was dried by a spray dryer to obtain a first pulverized powder. Drying was carried out under the conditions of raw material supply amount: 10 to 30 L / h, hot air inlet temperature: 200 to 250 ° C., and exhaust air temperature: 90 to 120 ° C.
  • the first crushed powder was put into a saggar made of Kojilite mullite material and calcined in an electric furnace.
  • the calcining conditions were air atmosphere, calcining temperature: 1150 ° C., and calcining time: 2 hours.
  • the second pulverized powder was put into a Teflon lining ball mill (“Teflon” is a registered trademark) together with alumina media, and dry pulverization was performed for 4 hours. As a result, a third pulverized powder was obtained.
  • Teflon is a registered trademark
  • a jet mill (STJ-200 manufactured by Seishin Enterprise Co., Ltd.) was used to make the third pulverized powder into fine particles.
  • the conditions for fine particle formation in the jet mill were a processing amount of 11 kg / hr, a pressure pressure of 0.7 MPa, and a gliding pressure of 0.7 MPa. In Comparative Example 1 and Example 1, this fine particle formation was not performed.
  • the calcined powder was wet-pulverized with a ball mill and then wet-pulverized with a bead mill to obtain a second pulverized powder, and the second pulverized powder was obtained.
  • An oxide-based solid electrolyte was produced in substantially the same manner as described above, except that the particles were pulverized. More specifically, in Examples 5 and 6, 400 g of the calcined powder obtained by calcining, 1.2 L of ion-exchanged water, 4 g of ammonium polyacrylate as a dispersant, and zirconia media (diameter).
  • Powder X-ray diffraction method was performed on each of Comparative Examples 1 and 2 and Examples 1 and 2 obtained as described above using PANalytical X'pert Pro, and each X-ray diffraction obtained thereby was performed.
  • the pattern was collated with the ICDD database (PANNalytical X-ray Database and PDF-4 + 2019RDB).
  • the X-ray diffraction pattern of Comparative Example 1 is shown in FIG. 1
  • the X-ray diffraction pattern of Comparative Example 2 is shown in FIG. 2
  • the X-ray diffraction pattern of Example 1 is shown in FIG. 3
  • the X-ray diffraction pattern of Example 2 is shown in FIG.
  • Each is shown in.
  • the average particle size D50 and the BET specific surface area of each of the oxide-based solid electrolytes of Comparative Examples 1 to 3 and Examples 1 to 6 were measured using LA-920 and Macsorb based on the above-mentioned methods, respectively.
  • the average particle size D50 of the oxide-based solid electrolyte of Comparative Example 1 was 41.9 ⁇ m, and the BET specific surface area was 1.0 m 2 / g.
  • the average particle size D50 of the oxide-based solid electrolyte of Comparative Example 2 was 20.0 ⁇ m, and the BET specific surface area was 2.0 m 2 / g.
  • the average particle size D50 of the oxide-based solid electrolyte of Comparative Example 3 was 1.3 ⁇ m, and the BET specific surface area was 2.0 m 2 / g.
  • the average particle size D50 of the oxide-based solid electrolyte of Example 1 was 1.0 ⁇ m, and the BET specific surface area was 5.0 m 2 / g.
  • the average particle size D50 of the oxide-based solid electrolyte of Example 2 was 0.9 ⁇ m, and the BET specific surface area was 5.0 m 2 / g.
  • the average particle size D50 of the oxide-based solid electrolyte of Example 3 was 1.0 ⁇ m, and the BET specific surface area was 5.0 m 2 / g.
  • the average particle size D50 of the oxide-based solid electrolyte of Example 4 was 0.6 ⁇ m, and the BET specific surface area was 10.0 m 2 / g.
  • the average particle size D50 of the oxide-based solid electrolyte of Example 5 was 0.4 ⁇ m, and the BET specific surface area was 25.0 m 2 / g.
  • the average particle size D50 of the oxide-based solid electrolyte of Example 6 was 0.2 ⁇ m, and the BET specific surface area was 30.0 m 2 / g.
  • the SEM image of the oxide-based solid electrolyte of Example 1 is shown in FIG. 5
  • the SEM image of the oxide-based solid electrolyte of Example 2 is shown in FIG.
  • uniaxial compression and cold isotropic pressurization were performed under the conditions shown in Tables 3 and 4 using the oxide-based solid electrolytes of Comparative Examples 1 to 3 and Examples 1 to 6. This was performed in this order to obtain a molded product. Specifically, 0.5 g of an oxide-based solid electrolyte was subjected to uniaxial compression of 40 MPa to prepare a green compact. Next, the green compact was placed in a cold isotropic pressurizing device, and cold isotropic pressurization (CIP) was performed on the green compact at a pressure of 200 MPa. As a result, a columnar molded body having a diameter of 5 mm and a length of 10 mm was obtained.
  • CIP cold isotropic pressurization
  • thermomechanical analyzer TMA, TMA8310 manufactured by Rigaku Co., Ltd.
  • the ultimate temperature in this measurement is 1350 ° C.
  • Tables 3 and 4 also show the densities measured after each treatment of uniaxial compression, CIP and TMA (Test Examples 1-14).
  • ESE-433-00 manufactured by ENERAPAC was used for uniaxial compression
  • CPP28-300B manufactured by NPA System Co., Ltd. was used for CIP.
  • the CIP condition was set to 150 MPa.
  • the sintering start temperature was sufficiently set to 900 ° C. or lower. I was able to lower it. From this, it was suggested that the oxide-based solid electrolyte of the present invention may be able to be sintered at a relatively low temperature.
  • the lithium ion conductivity of the oxide-based solid electrolyte of Example 2 was measured according to the following procedure. First, a 1 M aqueous solution of LiCl was impregnated into two 10 mm square filter papers and attached to both sides of a plate of the oxide-based solid electrolyte of Example 2 having a thickness of 2 mm. The oxide-based solid electrolyte of Example 2 was prepared in a 14 mm square shape, and the filter paper was prepared in a 10 mm square shape. This was sandwiched between electrodes made of stainless steel. Here, the LiCl aqueous solution impregnated in the filter paper was used as the electrolyte.
  • the ionic conductivity is the AC impedance using an LCR meter (HP4192A, manufactured by Hured Packard) in the frequency range of 5 Hz up to 13 MHz. Measured by method.
  • the ionic conductivity of the oxide-based solid electrolyte of Example 2 was 5 ⁇ 10 -4 S / cm (overall resistance 400 ⁇ ).
  • the ionic conductivity of the oxide-based solid electrolyte of Comparative Example 2 was measured in the same manner as in Example 2, it was 5 ⁇ 10 -4 S / cm (overall resistance 400 ⁇ ).

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Abstract

An oxide-based solid-state electrolyte according to the present invention is characterized by including a compound represented by the general formula, Ａ2/3-xＬｉ3xＴｉＯ3 (in the formula, x satisfies 0.04<x<0.14, A is at least one element selected from lanthanoid), wherein the solid-state electrolyte has an average grain diameter D50 of 0.1-1.0 μm, and a BET specific surface area of ５．０ｍ2／ｇ-１００．０ｍ2.

Description

酸化物系固体電解質Oxide-based solid electrolyte
　この発明は、たとえば二次電池の焼成型固体電解質等に用いて好適な酸化物系固体電解質に関するものであり、特に、全固体電池の製造時等における酸化物系固体電解質の低温焼結を可能にする技術を提案するものである。 The present invention relates to an oxide-based solid electrolyte suitable for use in, for example, a firing type solid electrolyte of a secondary battery, and in particular, enables low-temperature sintering of the oxide-based solid electrolyte during the production of an all-solid-state battery or the like. It proposes the technology to make it.
　二次電池のなかでも特に、電解質が固体からなる全固体リチウムイオン電池等の全固体電池は、液体電解質を用いるリチウムイオン電池に比して、優れた安定性及び信頼性、高エネルギー密度化、高出力化ならびに、広い作動温度等を実現できる可能性がある。それ故に、全固体電池は、自動車や電子機器、家庭用蓄電池等といった様々な用途での実用化が期待されている。 Among the secondary batteries, all-solid-state batteries such as all-solid-state lithium-ion batteries in which the electrolyte is a solid have excellent stability, reliability, and high energy density as compared with lithium-ion batteries using a liquid electrolyte. There is a possibility that high output and a wide operating temperature can be realized. Therefore, all-solid-state batteries are expected to be put into practical use in various applications such as automobiles, electronic devices, and household storage batteries.
　この全固体電池は一般に、気相法により作製される薄膜型と、微粒子を焼結させて作製されるバルク型に大別される。このうち、バルク型の全固体電池は、集電体間に正極活物質と固体電解質と負極活物質の各粒子を層状に積層させ、所定の温度で加熱することにより、それらの粒子を焼結させて形成される。バルク型の全固体電池の固体電解質は、固体電解質粒子を焼結させて得られるので、焼成型固体電解質と称されることがある。 This all-solid-state battery is generally classified into a thin film type manufactured by the vapor phase method and a bulk type manufactured by sintering fine particles. Of these, in the bulk type all-solid-state battery, particles of the positive electrode active material, the solid electrolyte, and the negative electrode active material are laminated in layers between the current collectors, and these particles are sintered by heating at a predetermined temperature. Is formed. The solid electrolyte of a bulk type all-solid-state battery is sometimes referred to as a fire-type solid electrolyte because it is obtained by sintering solid electrolyte particles.
　全固体電池の焼成型固体電解質に用いる材料の候補としては、種々のものが提案されているが、その材料の選定は、電池性能を大きく左右することから重要になる。それらのなかでも、Ａ2/3-xＬｉ3xＴｉＯ3（０＜ｘ＜０．１６、Ａ：ランタノイドから選択される一種以上の元素）で表される複合酸化物（いわゆる酸化物系固体電解質）、特にＡがＬａであるペロブスカイト結晶構造の複合酸化物（いわゆるＬＬＴＯ）は、高いイオン伝導率、安定性及び耐久性を有すること等の理由から有望視されている。 Various materials have been proposed as candidates for materials used for the calcined solid electrolyte of an all-solid-state battery, but the selection of the material is important because it greatly affects the battery performance. Among them, a composite oxide represented by A 2 / 3-x Li 3x TiO 3 (0 <x <0.16, A: one or more elements selected from lanthanoids) (so-called oxide-based solid electrolyte) ), In particular, a complex oxide having a perovskite crystal structure in which A is La (so-called LLTO) is promising because of its high ionic conductivity, stability and durability.
　この種の酸化物系固体電解質について記載された文献としては、たとえば特許文献１及び２がある。
　特許文献１には、「二次電池であって、正極、負極、及び前記正極と前記負極との間に介在された固体電解質層を備えてなり、前記正極及び前記負極が、固体電解質粒子として、第１固体電解質粒子のみを含んでなり、前記固体電解質層が、固体電解質粒子として、第２固体電解質粒子のみを含んでなり、前記第２固体電解質粒子の平均粒径が、前記第１固体電解質粒子の平均粒径よりも大きいものであり、前記第１固体電解質粒子の平均粒径が、１ｎｍから１００ｎｍであり、前記第２固体電解質粒子の平均粒径が、２μｍから１０μｍであり、前記第１固体電解質粒子及び前記第２固体電解質粒子が、下記化学式（１）で表わされる複合酸化物であり、Ｌｉ3xＬａ(2/3-x)ＴｉＯ3（０＜ｘ＜０．１６）　化学式（１）　前記第１固体電解質粒子内の２次相の比率が、前記第１固体電解質粒子の総重量に対して０．１重量％から５重量％であり、前記第２固体電解質粒子内の２次相の比率が、前記第２固体電解質粒子の総重量に対して０．１重量％から５重量％であることを特徴とする、二次電池」が開示されている。この特許文献１には、「前記第１固体電解質粒子の比表面積（ＢＥＴ）が１００ｍ2／ｇから４００ｍ2／ｇであり、前記第２固体電解質粒子の比表面積（ＢＥＴ）が１０ｍ2／ｇから５０ｍ2／ｇである」と記載されている。 Documents describing this type of oxide-based solid electrolyte include, for example, Patent Documents 1 and 2.
Patent Document 1 states that "a secondary battery includes a positive electrode, a negative electrode, and a solid electrolyte layer interposed between the positive electrode and the negative electrode, and the positive electrode and the negative electrode are solid electrolyte particles. , The solid electrolyte layer contains only the second solid electrolyte particles as the solid electrolyte particles, and the average particle size of the second solid electrolyte particles is the first solid. The average particle size of the first solid electrolyte particles is larger than the average particle size of the electrolyte particles, the average particle size of the first solid electrolyte particles is 1 nm to 100 nm, and the average particle size of the second solid electrolyte particles is 2 μm to 10 μm. The first solid electrolyte particles and the second solid electrolyte particles are composite oxides represented by the following chemical formula (1), and Li 3x La (2 / 3-x) TiO 3 (0 <x <0.16) chemical formula. (1) The ratio of the secondary phase in the first solid electrolyte particles is 0.1% by weight to 5% by weight with respect to the total weight of the first solid electrolyte particles, and is in the second solid electrolyte particles. A secondary battery is disclosed, wherein the ratio of the secondary phase is 0.1% by weight to 5% by weight based on the total weight of the second solid electrolyte particles. In Patent Document 1, "the specific surface area (BET) of the first solid electrolyte particles is 100 m 2 / g to 400 m 2 / g, and the specific surface area (BET) of the second solid electrolyte particles is 10 m 2 / g. From 50 m 2 / g. "
　特許文献２には、「下記化学式（１）で表される固体電解質粒子を製造する方法であって、Ｌｉ3xＬａ(2/3-x)ＴｉＯ3（０＜ｘ＜０．１６）　（１）　水系溶媒又は有機溶媒の下、チタン前駆体、ランタン前駆体、リチウム前駆体を混合し、前駆体溶液を製造する段階と、及び前記前駆体溶液を熱処理する段階とを含んでなり、前記チタン前駆体が、平均粒径（Ｄ50）が、０．５ｎｍから１０ｎｍであるチタン酸化物粒子を含んでなり、前記固体電解質粒子の平均粒径（Ｄ50）が、２０ｎｍから１００ｎｍであることを特徴とする、固体電解質粒子の製造方法」が提案されている。特許文献２では、「本発明の一実施形態によれば、前記固体電解質層をなす固体電解質粒子の比表面積は２００ｍ2／ｇから４００ｍ2／ｇであることが好ましい。」とされている。 Patent Document 2 states that "a method for producing solid electrolyte particles represented by the following chemical formula (1), which is Li 3x La (2 / 3-x) TiO 3 (0 <x <0.16) (1). ) A step of mixing a titanium precursor, a lanthanum precursor, and a lithium precursor under an aqueous solvent or an organic solvent to produce a precursor solution, and a step of heat-treating the precursor solution are included. The precursor comprises titanium oxide particles having an average particle size (D 50 ) of 0.5 nm to 10 nm, and the solid electrolyte particles having an average particle size (D 50 ) of 20 nm to 100 nm. A characteristic method for producing solid electrolyte particles "has been proposed. Patent Document 2 states that "according to one embodiment of the present invention, the specific surface area of the solid electrolyte particles forming the solid electrolyte layer is preferably 200 m 2 / g to 400 m 2 / g."
特許第５９５７６１８号公報Japanese Patent No. 5957618 特許第６１８１１９９号公報Japanese Patent No. 6181199
　上述したような焼成型固体電解質の形成に用いられる酸化物系固体電解質等では、比較的低温の加熱で焼結して、所定の高いイオン伝導率を発揮し得るものであることが求められる。これはすなわち、高い温度に加熱しなければ焼結しない酸化物系固体電解質では、正極活物質と負極活物質との間に配置して焼結させるべく当該高温に加熱した際に、正極活物質や負極活物質との間で反応が生じ、それらの界面で、イオン伝導率を低下させ得る物質が生成するおそれがあること等の理由によるものである。 The oxide-based solid electrolyte or the like used for forming the firing-type solid electrolyte as described above is required to be capable of exhibiting a predetermined high ionic conductivity by sintering with heating at a relatively low temperature. This means that in an oxide-based solid electrolyte that cannot be sintered unless it is heated to a high temperature, the positive electrode active material is placed between the positive electrode active material and the negative electrode active material and heated to the high temperature for sintering. This is because there is a possibility that a reaction may occur with the active material of the negative electrode or the negative electrode, and a substance capable of lowering the ionic conductivity may be generated at the interface between them.
　しかしながら、これまでのＡ2/3-xＬｉ3xＴｉＯ3（０＜ｘ＜０．１６、Ａ：ランタノイドから選択される一種以上の元素）の酸化物系固体電解質は、ある程度の高温に加熱しなければ焼結しないものであった。したがって、かかる酸化物系固体電解質は、たとえば焼成型固体電解質の形成等に用いるには、この点で改善が必要である。 However, the oxide-based solid electrolytes of A 2 / 3-x Li 3x TiO 3 (0 <x <0.16, A: one or more elements selected from lanthanoids) have been heated to a certain high temperature. Without it, it would not be sintered. Therefore, in order to use such an oxide-based solid electrolyte for, for example, forming a calcined solid electrolyte, improvement is required in this respect.
　特許文献１及び２に記載された酸化物系固体電解質粒子では、このような低温焼結を実現することができなかった。なお、特許文献１及び２の酸化物系固体電解質粒子は、焼成型固体電解質に用いられるものではなく、スクリーン印刷及び乾燥により固体電解質を形成するものであるから、そもそも上述したような低温焼結が要求されない。 Such low-temperature sintering could not be realized with the oxide-based solid electrolyte particles described in Patent Documents 1 and 2. The oxide-based solid electrolyte particles of Patent Documents 1 and 2 are not used for the firing type solid electrolyte, but form the solid electrolyte by screen printing and drying. Therefore, low-temperature sintering as described above is performed in the first place. Is not required.
　この発明は、このような問題を解決することを課題とするものであり、その目的は、比較的低い温度で焼結することができる酸化物系固体電解質を提供することにある。 The present invention has an object of solving such a problem, and an object of the present invention is to provide an oxide-based solid electrolyte that can be sintered at a relatively low temperature.
　発明者は鋭意検討の結果、所定の粒径かつ所定の比表面積を有する酸化物系固体電解質であれば、その焼結温度が有意に低下することを新たに見出した。 As a result of diligent studies, the inventor has newly found that the sintering temperature of an oxide-based solid electrolyte having a predetermined particle size and a predetermined specific surface area is significantly lowered.
　このような知見の下、この発明の酸化物系固体電解質は、下記一般式（Ｉ）
　　Ａ2/3-xＬｉ3xＴｉＯ3　　　（Ｉ）
　　（式中、ｘは、０．０４＜ｘ＜０．１４を満たし、Ａは、ランタノイドから選択される一種以上の元素である。）
で表される化合物を含み、平均粒径Ｄ５０が０．１μｍ～１．０μｍであり、ＢＥＴ比表面積が５．０ｍ2／ｇ～１００．０ｍ2／ｇであることを特徴とするものである。 Based on such knowledge, the oxide-based solid electrolyte of the present invention has the following general formula (I).
A 2 / 3-x Li 3x TiO 3 (I)
(In the formula, x satisfies 0.04 <x <0.14, and A is one or more elements selected from lanthanoids.)
Comprising a compound represented by in a mean particle size D50 0.1 [mu] m ~ 1.0 .mu.m, in which BET specific surface area is characterized by a 5.0m 2 /g~100.0m 2 / g ..
　なお、前記一般式（Ｉ）Ａ2/3-xＬｉ3xＴｉＯ3で表される化合物中のＡは、Ｌａとすることができる。
　また、この発明の酸化物系固体電解質は、焼結開始温度が９００℃以下であることが好ましい。 In addition, A in the compound represented by the general formula (I) A 2 / 3-x Li 3x TiO 3 can be La.
Further, the oxide-based solid electrolyte of the present invention preferably has a sintering start temperature of 900 ° C. or lower.
　この発明の酸化物系固体電解質は、比較的低い温度で焼結することができる。それにより、当該酸化物系固体電解質は、全固体電池を含む二次電池の焼成型固体電解質に好適に用いることができる。 The oxide-based solid electrolyte of the present invention can be sintered at a relatively low temperature. As a result, the oxide-based solid electrolyte can be suitably used as a fired solid electrolyte for a secondary battery including an all-solid-state battery.
比較例１のＸ線回折パターンを示すグラフである。It is a graph which shows the X-ray diffraction pattern of the comparative example 1. FIG. 比較例２のＸ線回折パターンを示すグラフである。It is a graph which shows the X-ray diffraction pattern of the comparative example 2. 実施例１のＸ線回折パターンを示すグラフである。It is a graph which shows the X-ray diffraction pattern of Example 1. FIG. 実施例２のＸ線回折パターンを示すグラフである。It is a graph which shows the X-ray diffraction pattern of Example 2. 実施例１の固体電解質粒子のＳＥＭ画像である。6 is an SEM image of the solid electrolyte particles of Example 1. 実施例２の固体電解質粒子のＳＥＭ画像である。6 is an SEM image of the solid electrolyte particles of Example 2.
　以下に、この発明の実施の形態について詳細に説明する。
　この発明の一の実施形態の酸化物系固体電解質は、たとえば二次電池の焼成型固体電解質に用いられる粒子状ないし粉末状等のものであり、下記一般式（Ｉ）
　　Ａ2/3-xＬｉ3xＴｉＯ3　　　（Ｉ）
　　（式中、ｘは、０．０４＜ｘ＜０．１４を満たし、Ａは、ランタノイドから選択される一種以上の元素である。）
　で表される化合物を含み、該一般式（Ｉ）中のＡは、ランタン（Ｌａ）、セリウム（Ｃｅ）、プラセオジム（Ｐｒ）、ネオジム（Ｎｄ）、プロメチウム（Ｐｍ）、サマリウム（Ｓｍ）、ユウロピウム（Ｅｕ）、ガドリニウム（Ｇｄ）、テルビウム（Ｔｂ）、ジスプロシウム（Ｄｙ）、ホルミウム（Ｈｏ）、エルビウム（Ｅｒ）、ツリウム（Ｔｍ）、イッテルビウム（Ｙｂ）、ルテチウム（Ｌｕ）から選択される一種以上のランタノイドである。
　また、この発明の一の実施形態の酸化物系固体電解質は、平均粒径Ｄ５０が０．１μｍ～１．０μｍであり、ＢＥＴ比表面積が５．０ｍ2／ｇ～１００．０ｍ2／ｇである。 Hereinafter, embodiments of the present invention will be described in detail.
The oxide-based solid electrolyte according to the embodiment of the present invention is, for example, a particulate or powder used for a calcined solid electrolyte of a secondary battery, and has the following general formula (I).
A 2 / 3-x Li 3x TiO 3 (I)
(In the formula, x satisfies 0.04 <x <0.14, and A is one or more elements selected from lanthanoids.)
A in the general formula (I) is lanthanum (La), cerium (Ce), placeodim (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium. (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), formium (Ho), erbium (Er), samarium (Tm), ytterbium (Yb), lutetium (Lu) It is a lantanoid.
The oxide-based solid electrolyte of one embodiment of the invention, the average particle size D50 0.1 [mu] m ~ 1.0 .mu.m, BET specific surface area in the 5.0m 2 /g~100.0m 2 / g is there.
（組成）
　酸化物系固体電解質は、上記一般式（Ｉ）で表される化合物を含むものである。この化合物は、より具体的には、ＬＬＴＯ等の複合酸化物である場合がある。酸化物系固体電解質は、特に、上記一般式（Ｉ）中のＡがＬａであるＬａ2/3-xＬｉ3xＴｉＯ3（０．０４＜ｘ＜０．１４）の化合物を含むことが好適である。たとえば、一般式（Ｉ－ａ）で表されるＬａxＬｉ2-3xＴｉＯ3-aＳｒＴｉＯ3、一般式（Ｉ－ｂ）で表されるＬａxＬｉ2-3xＴｉＯ3-aＬａ0.5Ｋ0.5ＴｉＯ3、一般式（Ｉ－ｃ）で表されるＬａxＬｉ2-3xＴｉ1-aＭaＯ3-a、又は、一般式（Ｉ－ｄ）で表されるＳｒx-1.5aＬａaＬｉ1.5-2xＴｉ0.5Ｔａ0.5Ｏ3（式（Ｉ－ａ）から式（Ｉ－ｄ）中、ｘは、０．５５≦ｘ≦０．５９を満たし、ａは、０≦ａ≦０．２を満たし、Ｍは、Ａｌ、Ｆｅ、Ｇａから選択される少なくとも一種である。）で表され、Ａｌ2Ｏ3含有量としては０．３５重量％以下、かつＳｉＯ2含有量としては０．１重量％以下であるもの等が挙げられる。 (composition)
The oxide-based solid electrolyte contains a compound represented by the above general formula (I). More specifically, this compound may be a composite oxide such as LLTO. The oxide-based solid electrolyte preferably contains a compound of La 2 / 3-x Li 3x TiO 3 (0.04 <x <0.14) in which A in the general formula (I) is La. Is. For example, La x Li 2-3x TiO 3-a SrTiO 3 represented by the general formula (Ia), La x Li 2-3x TiO 3-a La 0.5 K represented by the general formula (Ib). 0.5 TiO 3, the general formula La x represented by (I-c) Li 2-3x Ti 1-a M a O 3-a, or, Sr x-1.5a of the general formula (I-d) La a Li 1.5-2x Ti 0.5 Ta 0.5 O 3 (In formulas (Ia) to ( Id ), x satisfies 0.55 ≦ x ≦ 0.59, and a is 0 ≦ a ≦. It satisfies 0.2, and M is at least one selected from Al, Fe, and Ga.), The Al 2 O 3 content is 0.35% by weight or less, and the SiO 2 content is Examples thereof include those having a weight of 0.1% by weight or less.
　酸化物系固体電解質が、上記一般式（Ｉ）で表される化合物を含むことは、粉末Ｘ線回折法により確認することができる。粉末Ｘ線回折法では、ＰＡＮａｌｙｔｉｃａｌ　Ｘ’ｐｅｒｔ　Ｐｒｏにより得られた酸化物系固体電解質のＸ線回折パターンを、ＩＣＤＤデータベース（ＰＡＮａｌｙｔｉｃａｌ　Ｅｘａｍｐｌｅ　ＤａｔａｂａｓｅとＰＤＦ－４＋　２０１９ＲＤＢ）と照合して、酸化物系固体電解質中に含まれる上記一般式（Ｉ）で表される化合物を同定する。 It can be confirmed by the powder X-ray diffraction method that the oxide-based solid electrolyte contains the compound represented by the above general formula (I). In the powder X-ray diffraction method, the X-ray diffraction pattern of the oxide-based solid electrolyte obtained by PANalytical X'pert Pro is collated with the ICDD database (PANalytical Exclusive Database and PDF-4 + 2019RDB), and the oxide-based solid electrolyte is collated. The compound represented by the above general formula (I) contained therein is identified.
　ここでは、粉末Ｘ線回折法により得られノイズを除去した酸化物系固体電解質のＸ線回折パターンを上記ＩＣＤＤデータベースと照合して、該酸化物系固体電解質のＸ線回折パターン中に上記一般式（Ｉ）で表される化合物のＸ線回折パターンが存在すると認められる場合に、酸化物系固体電解質中に上記一般式（Ｉ）で表される化合物が含まれていると判断する。一方、同様に上記ＩＣＤＤデータベースと照合して、該酸化物系固体電解質のＸ線回折パターン中に上記一般式（Ｉ）で表される化合物のＸ線回折パターンが存在しないと認められない場合には、酸化物系固体電解質中に上記一般式（Ｉ）で表される化合物が含まれていないと判断する。 Here, the X-ray diffraction pattern of the oxide-based solid electrolyte obtained by the powder X-ray diffraction method and from which noise has been removed is collated with the above ICDD database, and the above general formula is included in the X-ray diffraction pattern of the oxide-based solid electrolyte. When it is recognized that the X-ray diffraction pattern of the compound represented by (I) exists, it is determined that the oxide-based solid electrolyte contains the compound represented by the above general formula (I). On the other hand, similarly, when it is not recognized that the X-ray diffraction pattern of the compound represented by the general formula (I) does not exist in the X-ray diffraction pattern of the oxide-based solid electrolyte by collating with the ICDD database. Determines that the oxide-based solid electrolyte does not contain the compound represented by the above general formula (I).
　酸化物系固体電解質中の上記一般式（Ｉ）で表される化合物は、酸素の一部がＦやＣｌなどの他の元素に置換されている場合や、遷移金属の一部が、Ｆｅ、Ｃｒ、Ｔｉ、Ｎｂ、Ｗ、Ｍｏ、Ｎａ、Ｋ、Ｍｇ、Ｃａなどの他の金属で置換されている場合がある。また、上記一般式（Ｉ）で表される化合物の化学量論組成に対してＬｉや酸素が過剰か欠損の場合もある。さらに、酸化物系固体電解質中の上記一般式（Ｉ）で表される化合物の結晶構造に歪みが生じている場合もある。この発明の実施形態においては、このような化合物の化学量論組成に対して構成元素の置換、欠損もしくは過剰の場合、または結晶構造に歪みが生じた場合についても、酸化物系固体電解質の特性に変化が生じない範囲内であれば、上記一般式（Ｉ）で表される化合物として許容され得る。
　なお、構成元素が欠損している化合物や構成元素が過剰な化合物の各Ｘ線回折パターンを上記ＩＣＤＤデータベースに照合した場合、上記一般式（Ｉ）で表される化合物のＸ線回折パターンからピークがシフト（ピークシフト）する可能性がある。しかしながら、この発明の実施形態においては、そのようなピークシフトについても、上記ＩＣＤＤデータベースのリファレンス値に対して±１０％以内であれば、酸化物系固体電解質中に上記一般式（Ｉ）で表される化合物が含まれていると判断する。 In the compound represented by the above general formula (I) in the oxide-based solid electrolyte, when a part of oxygen is replaced with another element such as F or Cl, or a part of the transition metal is Fe, It may be replaced with other metals such as Cr, Ti, Nb, W, Mo, Na, K, Mg and Ca. In addition, Li and oxygen may be excessive or deficient with respect to the stoichiometric composition of the compound represented by the general formula (I). Further, the crystal structure of the compound represented by the above general formula (I) in the oxide-based solid electrolyte may be distorted. In the embodiment of the present invention, the characteristics of the oxide-based solid electrolyte even when the constituent elements are substituted, deleted or excessive with respect to the stoichiometric composition of such a compound, or when the crystal structure is distorted. As long as it does not change, it can be accepted as a compound represented by the above general formula (I).
When each X-ray diffraction pattern of the compound lacking the constituent element or the compound having the excess constituent element is collated with the ICDD database, the peak is obtained from the X-ray diffraction pattern of the compound represented by the general formula (I). May shift (peak shift). However, in the embodiment of the present invention, even for such a peak shift, if it is within ± 10% with respect to the reference value of the ICDD database, it is represented by the above general formula (I) in the oxide-based solid electrolyte. It is judged that the compound to be used is contained.
　酸化物系固体電解質中に、上記一般式（Ｉ）で表される化合物は、９９．０質量％以上で含まれることが好ましく、さらに９９．５質量％以上で含まれることがより一層好ましい。この化合物の含有量は多いほど望ましいので、その好ましい上限値は特にないが、たとえば９９．９９９質量％以下、典型的には９９．９９質量％以下になることがある。当該化合物の含有量は、ＩＣＰ（Ｉｎｄｕｃｔｉｖｅｌｙ　Ｃｏｕｐｌｅｄ　Ｐｌａｓｍａ）により測定する。
　酸化物系固体電解質は、上記一般式（Ｉ）で表される化合物の他、不純物として、Ｓｉ、Ａｌ及びＦｅからなる群から選択される少なくとも一種を含むことがある。当該酸化物系固体電解質中の不純物の含有量は、好ましくは１．０質量％以下、より好ましくは０．５質量％以下である。 The compound represented by the general formula (I) is preferably contained in an oxide-based solid electrolyte in an amount of 99.0% by mass or more, and even more preferably 99.5% by mass or more. Since the higher the content of this compound is, the more desirable it is, there is no particular preferable upper limit value thereof, but for example, it may be 99.999% by mass or less, typically 99.99% by mass or less. The content of the compound is measured by ICP (Inductively Coupled Plasma).
The oxide-based solid electrolyte may contain at least one selected from the group consisting of Si, Al and Fe as impurities in addition to the compound represented by the above general formula (I). The content of impurities in the oxide-based solid electrolyte is preferably 1.0% by mass or less, more preferably 0.5% by mass or less.
　一般に、固体電解質とは、外部から加えられた電場によってイオン（帯電した物質）を移動させることができる固体と認識されている。また、固体電解質からは、イオンの移動を利用して電力を取り出すこともできる。この発明の実施形態においては、酸化物である固体電解質（酸化物系固体電解質）を対象とする。この発明の実施形態の酸化物系固体電解質は、二次電池の発電材料や電解コンデンサの電極導体に用いることができるほか、ガスセンサやガス分離・製造などの各種固体電解質デバイスへ適用することも考えられる。 Generally, a solid electrolyte is recognized as a solid capable of moving ions (charged substances) by an electric field applied from the outside. In addition, electric power can be extracted from the solid electrolyte by utilizing the movement of ions. In the embodiment of the present invention, a solid electrolyte (oxide-based solid electrolyte) that is an oxide is targeted. The oxide-based solid electrolyte of the embodiment of the present invention can be used as a power generation material for a secondary battery or an electrode conductor of an electrolytic capacitor, and may also be applied to various solid electrolyte devices such as gas sensors and gas separation / manufacturing. Be done.
　この発明の実施形態においては、上記一般式（Ｉ）で表される化合物を含む酸化物系固体電解質を、たとえば二次電池の発電材料に適用する場合に、２７℃で測定したときのリチウムイオン伝導率が、たとえば５×１０-4Ｓｃｍ-1以上、さらに６×１０-4Ｓｃｍ-1以上であることが好ましい。酸化物系固体電解質のリチウムイオン伝導率を測定するには、インピーダンス法を用いる。
　インピーダンス法による酸化物系固体電解質のリチウムイオン伝導率の測定例は、以下に示すとおりである。なお、ここでは、上記一般式（Ｉ）で表される化合物を含む酸化物系固体電解質を用いた測定手順を例に挙げて説明する。
　１ＭのＬｉＣｌ水溶液を、１０ｍｍ角の２枚の濾紙に染み込ませ、厚さ２ｍｍの上記一般式（Ｉ）で表される化合物を含む酸化物系固体電解質のプレートの両面に張り付ける。上記一般式（Ｉ）で表される化合物を含む酸化物系固体電解質は１４ｍｍ角、濾紙は１０ｍｍ角で用意する。これを、ステンレス鋼からなる電極で挟み込む。ここでは、濾紙に染み込ませたＬｉＣｌ水溶液が、電解質として使われる。上記一般式（Ｉ）で表される化合物を含む酸化物系固体電解質の粒界の影響を明らかにするために、イオン伝導率は、１３ＭＨｚまで５Ｈｚの周波数レンジで、ＬＣＲメータ（ヒューレッドパッカード社製、ＨＰ４１９２Ａ）を用いたＡＣインピーダンス法で測定する。 In the embodiment of the present invention, when an oxide-based solid electrolyte containing the compound represented by the above general formula (I) is applied to a power generation material of a secondary battery, for example, lithium ions measured at 27 ° C. It is preferable that the conductivity is, for example, 5 × 10 -4 Scm -1 or more, and further preferably 6 × 10 -4 Scm -1 or more. The impedance method is used to measure the lithium ion conductivity of the oxide-based solid electrolyte.
An example of measuring the lithium ion conductivity of the oxide-based solid electrolyte by the impedance method is as shown below. Here, a measurement procedure using an oxide-based solid electrolyte containing the compound represented by the general formula (I) will be described as an example.
A 1 M aqueous solution of LiCl is impregnated into two 10 mm square filter papers and attached to both sides of a plate of an oxide-based solid electrolyte containing a compound represented by the above general formula (I) having a thickness of 2 mm. The oxide-based solid electrolyte containing the compound represented by the general formula (I) is prepared in a size of 14 mm square, and the filter paper is prepared in a size of 10 mm square. This is sandwiched between electrodes made of stainless steel. Here, the LiCl aqueous solution soaked in the filter paper is used as the electrolyte. In order to clarify the influence of the grain boundaries of the oxide-based solid electrolyte containing the compound represented by the general formula (I), the ionic conductivity is in the frequency range of 5 Hz up to 13 MHz, and the LCR meter (Huled Packard Co., Ltd.) It is measured by the AC impedance method using HP4192A).
（粒径）
　粉末状の酸化物系固体電解質の平均粒径Ｄ５０は、０．１μｍ～１．０μｍとする。平均粒径Ｄ５０がこの範囲内であり、かつ、後述するようにＢＥＴ比表面積が所定の範囲内であれば、たとえば１０００℃以下の比較的低温の加熱で、粒子同士の固結が始まって焼結が開始される。この温度を、本明細書では「焼結開始温度」と記載することがある。これは高温時の原子の移動によるものと考えられるが、このような理論に限定されない。
　なお、これまでの酸化物系固体電解質に含まれる複合酸化物粒子は、１４００℃以上の高温に加熱しなければ焼結が始まらなかった。これに対し、この発明の実施形態の酸化物系固体電解質では、その焼結開始温度を１０００℃以下、好ましくは９００℃以下、より好ましくは２００℃～９００℃まで低くすることができる場合がある。これにより、酸化物系固体電解質を全固体電池等の電池の製造に用いた場合、より有効な低温焼結が可能になる。このような低い焼結温度は、酸化物系固体電解質の先述した平均粒径Ｄ５０、後述するＢＥＴ比表面積等により実現することができる。焼結開始温度は、熱機械分析装置（ＴＭＡ）に基いて決定することができる。 (Particle size)
The average particle size D50 of the powdered oxide-based solid electrolyte is 0.1 μm to 1.0 μm. If the average particle size D50 is within this range and the BET specific surface area is within a predetermined range as described later, the particles will start to solidify and be baked by heating at a relatively low temperature of, for example, 1000 ° C. or lower. The conclusion is started. This temperature may be referred to as "sintering start temperature" in the present specification. This is thought to be due to the movement of atoms at high temperatures, but is not limited to such a theory.
The composite oxide particles contained in the conventional oxide-based solid electrolyte did not start sintering unless they were heated to a high temperature of 1400 ° C. or higher. On the other hand, in the oxide-based solid electrolyte of the embodiment of the present invention, the sintering start temperature may be lowered to 1000 ° C. or lower, preferably 900 ° C. or lower, more preferably 200 ° C. to 900 ° C. .. As a result, when the oxide-based solid electrolyte is used in the production of a battery such as an all-solid-state battery, more effective low-temperature sintering becomes possible. Such a low sintering temperature can be realized by the above-mentioned average particle size D50 of the oxide-based solid electrolyte, the BET specific surface area described later, and the like. The sintering start temperature can be determined based on a thermomechanical analyzer (TMA).
　熱機械分析装置（ＴＭＡ）を用いた酸化物系固体電解質の焼結開始温度の測定例は、以下に示すとおりである。
　まず、０．５ｇの酸化物系固体電解質に対して４０ＭＰａの一軸圧縮を施して圧粉体を作製する。次いで、この圧粉体を冷間等方圧加圧装置に配置し、該圧粉体に対して２００ＭＰａの圧力で冷間等方圧加圧（ＣＩＰ）を行う。これにより、直径５ｍｍ、長さ１０ｍｍの円柱状の成形体を得る。その後、この成形体の焼結開始温度を、熱機械分析装置（ＴＭＡ）により測定する。
　なお、焼結開始温度は、熱機械分析装置（ＴＭＡ）を用いて空気中で酸化物系固体電解質の成形体を５℃／分で昇温した際の、相互に接触した粒子（相互接触粒子）の長さの収縮率が０．１％に達したときの温度を意味する。通常、粒子の焼結は、焼結前の粒子の消耗と粒子同士の接合部の成長によって進行し、同時に収縮が起こる。すなわち、ここでいう収縮率とは、複数の粒子を焼結させた場合において、焼結前の相互接触粒子の長さＬ1に対する、焼結前の相互接触粒子の長さＬ1と焼結後の相互接触粒子の長さＬ2の差ΔＬ（＝Ｌ1－Ｌ2）の比（ΔＬ／Ｌ1）の百分率（％）を意味する。この発明においては、ＴＭＡにより測定時に、該収縮率が０．１％となった時の温度を焼結開始温度とする。 An example of measuring the sintering start temperature of the oxide-based solid electrolyte using a thermomechanical analyzer (TMA) is as shown below.
First, 0.5 g of an oxide-based solid electrolyte is subjected to uniaxial compression of 40 MPa to prepare a green compact. Next, the green compact is placed in a cold isotropic pressurizing device, and cold isotropic pressurization (CIP) is performed on the green compact at a pressure of 200 MPa. As a result, a columnar molded body having a diameter of 5 mm and a length of 10 mm is obtained. Then, the sintering start temperature of this molded product is measured by a thermomechanical analyzer (TMA).
The sintering start temperature is the particles that are in contact with each other (mutual contact particles) when the molded body of the oxide-based solid electrolyte is heated at 5 ° C./min in the air using a thermomechanical analyzer (TMA). ) Means the temperature at which the shrinkage rate reaches 0.1%. Normally, the sintering of particles proceeds by the consumption of particles before sintering and the growth of joints between particles, and at the same time, shrinkage occurs. That is, the shrinkage rate referred to here is the length L 1 of the mutual contact particles before sintering and the length L 1 of the mutual contact particles before sintering with respect to the length L 1 of the mutual contact particles before sintering when a plurality of particles are sintered. It means the percentage (%) of the ratio (ΔL / L 1 ) of the difference ΔL (= L 1 − L 2 ) of the lengths L 2 of the later intercontact particles. In the present invention, the temperature at which the shrinkage rate becomes 0.1% at the time of measurement by TMA is defined as the sintering start temperature.
　また、酸化物系固体電解質の平均粒径Ｄ５０をこのように比較的小さくすることにより、焼結時の密度を高めることができる。その結果として、イオン伝導率が向上し、全固体電池の焼成型固体電解質に好適に用いることができる。 Further, by making the average particle size D50 of the oxide-based solid electrolyte relatively small in this way, the density at the time of sintering can be increased. As a result, the ionic conductivity is improved, and it can be suitably used for a calcined solid electrolyte of an all-solid-state battery.
　平均粒径Ｄ５０が１．０μｍを超える場合は、そのような低温焼結の実現が困難となる可能性がある。一方、平均粒径Ｄ５０が０．１μｍ未満である場合は、粒子が微細になりすぎて凝集しやすくなる等といったように、ハンドリング性の点で不都合が生じる。この観点から、酸化物系固体電解質の平均粒径Ｄ５０は、より好ましくは０．１μｍ～０．９μｍとする。 If the average particle size D50 exceeds 1.0 μm, it may be difficult to realize such low temperature sintering. On the other hand, when the average particle size D50 is less than 0.1 μm, the particles become too fine and easily aggregate, which causes inconvenience in terms of handleability. From this viewpoint, the average particle size D50 of the oxide-based solid electrolyte is more preferably 0.1 μm to 0.9 μm.
　酸化物系固体電解質の平均粒径Ｄ５０は、レーザー回折・散乱法により求められる粒度分布測定で、体積基準の累積分布が５０％となる粒径を指し、ＪＩＳ　Ｚ８８２５：２０１３に基いて測定する。 The average particle size D50 of the oxide-based solid electrolyte refers to the particle size at which the cumulative distribution on a volume basis is 50% in the particle size distribution measurement obtained by the laser diffraction / scattering method, and is measured based on JIS Z8825: 2013.
（表面積）
　酸化物系固体電解質のＢＥＴ比表面積は、５．０ｍ2／ｇ～１００．０ｍ2／ｇとする。上述した平均粒径Ｄ５０とともに、ＢＥＴ比表面積がこの範囲内になるように調整することにより、先に述べたように、低い温度での焼結が可能になる。ＢＥＴ比表面積が５．０ｍ2／ｇを下回る場合は、焼結温度が十分に低下しない。また、ＢＥＴ比表面積が１００．０ｍ2／ｇより大きい場合は、ハンドリング性の低下といった不都合が生じる。それ故に、ＢＥＴ比表面積は、さらに５．０ｍ2／ｇ～５０．０ｍ2／ｇとすることがより一層好ましい。 (Surface area)
BET specific surface area of the oxide-based solid electrolyte, and 5.0m 2 /g~100.0m 2 / g. By adjusting the BET specific surface area so as to be within this range together with the average particle size D50 described above, sintering at a low temperature becomes possible as described above. When the BET specific surface area is less than 5.0 m 2 / g, the sintering temperature does not drop sufficiently. Further, when the BET specific surface area is larger than 100.0 m 2 / g, inconvenience such as deterioration of handleability occurs. Therefore, BET specific surface area, it is more preferable to further 5.0m 2 /g~50.0m 2 / g.
　酸化物系固体電解質のＢＥＴ比表面積は、ＢＥＴ法により測定する。 The BET specific surface area of the oxide-based solid electrolyte is measured by the BET method.
（焼結体密度）
　上述した酸化物系固体電解質は、それに対して２００ＭＰａの圧力で冷間等方圧加圧（ＣＩＰ）を行って得られる成形体を焼結して得られた焼結体の密度（焼結体密度）が、４．５０ｇ／ｃｍ3～５．２３ｇ／ｃｍ3になることが好ましい。この場合、焼成型固体電解質を形成する際の焼結で、酸化物系固体電解質の粒成長が促進されて、イオン伝導率がさらに向上する。 (Sintered body density)
The above-mentioned oxide-based solid electrolyte has a density of a sintered body obtained by sintering a molded body obtained by subjecting it to cold isotropic pressure (CIP) at a pressure of 200 MPa (sintered body). density), it is preferable to be 4.50g / cm 3 ~ 5.23g / cm 3. In this case, the sintering when forming the calcined solid electrolyte promotes the grain growth of the oxide-based solid electrolyte, and the ionic conductivity is further improved.
　焼結体密度は、４．９０ｇ／ｃｍ3～５．２３ｇ／ｃｍ3であることがより一層好ましい。焼結体密度が低すぎると、イオン伝導性が低下するおそれがある。 Sintered density, it is more preferably 4.90g / cm 3 ~ 5.23g / cm 3. If the sintered body density is too low, the ionic conductivity may decrease.
　焼結体密度は具体的には次のようにして測定する。はじめに、０．５ｇの酸化物系固体電解質に対して４０ＭＰａの一軸圧縮を施して圧粉体を作製する。次いで、この圧粉体を冷間等方圧加圧装置に配置し、該圧粉体に対して２００ＭＰａの圧力で冷間等方圧加圧を行う。これにより、直径５ｍｍ、長さ１０ｍｍの円柱状の成形体を得る。そして、得られた成形体を焼結して焼結体を得る。その後、この焼結体の密度を、焼結体の寸法と重量により測定する。なお、この発明の実施形態の酸化物系固体電解質では、その焼結温度を１０００℃以下、好ましくは９００℃以下、より好ましくは２００℃～９００℃とすることができる場合がある。 Specifically, the sintered body density is measured as follows. First, 0.5 g of an oxide-based solid electrolyte is subjected to uniaxial compression of 40 MPa to prepare a green compact. Next, this green compact is placed in a cold isotropic pressurizing device, and cold isotropic pressurization is performed on the green compact at a pressure of 200 MPa. As a result, a columnar molded body having a diameter of 5 mm and a length of 10 mm is obtained. Then, the obtained molded product is sintered to obtain a sintered body. Then, the density of the sintered body is measured by the size and weight of the sintered body. In addition, in the oxide-based solid electrolyte of the embodiment of the present invention, the sintering temperature may be 1000 ° C. or lower, preferably 900 ° C. or lower, more preferably 200 ° C. to 900 ° C.
（製造方法）
　上述した酸化物系固体電解質を製造するには、たとえば、原料準備工程、第一湿式粉砕工程、仮焼工程、第二湿式粉砕工程、乾式粉砕工程および微粒子化工程をこの順に行うことにより製造することができる。より詳細には以下のとおりである。 (Production method)
In order to produce the above-mentioned oxide-based solid electrolyte, for example, the raw material preparation step, the first wet pulverization step, the calcining step, the second wet pulverization step, the dry pulverization step and the pulverization step are performed in this order. be able to. More details are as follows.
　はじめに、リチウム原料として水酸化リチウム、炭酸リチウム等のリチウム化合物を、またチタン原料として酸化チタン、メタチタン酸、オルトチタン酸等のチタン化合物を、さらにランタン原料として酸化ランタンをそれぞれ準備する原料準備工程を行う。なお必要に応じて、Ｓｒ、Ｋ、Ｆｅ、Ｇａ及びＴａからなる群から選択される少なくとも一種の水酸化物、塩化物及び／又は炭酸塩等も準備する。 First, a raw material preparation process for preparing lithium compounds such as lithium hydroxide and lithium carbonate as lithium raw materials, titanium compounds such as titanium oxide, metatitanium acid, and orthotitanic acid as titanium raw materials, and lanthanum oxide as lantern raw materials. Do. If necessary, at least one hydroxide, chloride and / or carbonate selected from the group consisting of Sr, K, Fe, Ga and Ta is also prepared.
　原料準備工程では、チタン原料として、粒径の比較的小さい酸化チタン等のチタン化合物を準備することが重要である。これにより、製造しようとする酸化物系固体電解質の平均粒径Ｄ５０及びＢＥＴ比表面積をそれぞれ所定の範囲内に調整しやすくなる。但し、チタン化合物の粒径が小さすぎると、ハンドリング性に問題が生じる。具体的には、酸化チタン等のチタン化合物の平均粒径Ｄ５０は、好ましくは０．１μｍ～１．０μｍ、より好ましくは０．１μｍ～０．９μｍとする。また、チタン原料として用いるチタン化合物は、ＢＥＴ比表面積が、好ましくは５．０ｍ2／ｇ～１００．０ｍ2／ｇ、より好ましくは５．０ｍ2／ｇ～５０．０ｍ2／ｇである。チタン化合物の平均粒径Ｄ５０及びＢＥＴ比表面積はそれぞれ、酸化物系固体電解質の平均粒径Ｄ５０及びＢＥＴ比表面積について先に述べた方法と同様にして測定する。 In the raw material preparation step, it is important to prepare a titanium compound such as titanium oxide having a relatively small particle size as a titanium raw material. As a result, the average particle size D50 and the BET specific surface area of the oxide-based solid electrolyte to be produced can be easily adjusted within predetermined ranges. However, if the particle size of the titanium compound is too small, there will be a problem in handleability. Specifically, the average particle size D50 of the titanium compound such as titanium oxide is preferably 0.1 μm to 1.0 μm, and more preferably 0.1 μm to 0.9 μm. Further, the titanium compound used as the titanium raw material, BET specific surface area is preferably 5.0m 2 /g~100.0m 2 / g, more preferably 5.0m 2 /g~50.0m 2 / g. The average particle size D50 and the BET specific surface area of the titanium compound are measured in the same manner as in the method described above for the average particle size D50 and the BET specific surface area of the oxide-based solid electrolyte, respectively.
　次いで、第一湿式粉砕工程として、上記のリチウム原料、チタン原料及びランタン原料等の原料を所定のモル比で、ボールミル等にて混合して粉砕する。ボールミルには、純水とエタノール等のアルコールの混合溶媒及び、必要に応じて界面活性剤等の分散媒を投入し、その状態で原料の粉砕を行う。なお、リチウム原料は、仮焼工程及び焼結工程での揮発分を考慮して、所期する組成のリチウム量よりも０重量％～１５重量％多く添加することがある。 Next, as the first wet pulverization step, the above-mentioned raw materials such as lithium raw material, titanium raw material and lantern raw material are mixed and pulverized at a predetermined molar ratio by a ball mill or the like. A mixed solvent of pure water and alcohol such as ethanol and a dispersion medium such as a surfactant are added to the ball mill as needed, and the raw materials are pulverized in that state. The lithium raw material may be added in an amount of 0% by weight to 15% by weight more than the amount of lithium having the desired composition in consideration of the volatile matter in the calcining step and the sintering step.
　ここで、ボールミルに投入する溶媒として、純水とアルコールの混合溶媒を用いることにより、原料が凝集せず分散しやすくなるので、水のみで粉砕する場合よりも粉砕時間を短縮することができる。 Here, by using a mixed solvent of pure water and alcohol as the solvent to be charged into the ball mill, the raw materials do not aggregate and are easily dispersed, so that the crushing time can be shortened as compared with the case of pulverizing only with water.
　またここでは、ボールミルで、たとえば、２０分～５０分にわたって粉砕した後、１０時間～２０時間放置し、その後、再度２０分～５０分の粉砕を行うことができる。粉砕の間に１０時間～２０時間放置することにより、原料のリチウム化合物、ランタン化合物の一部が溶出してその粒径が小さくなるので、粉砕に要する時間を短縮することができる。
　このようにして粉砕時間を短縮すれば、アルミナライニングボールミルを用いた場合のＡｌ2Ｏ3及びＳｉＯ2成分の混入を抑制することができる。 Further, here, it is possible to grind with a ball mill for, for example, 20 to 50 minutes, leave it for 10 to 20 hours, and then grind again for 20 to 50 minutes. By leaving it for 10 to 20 hours during pulverization, a part of the raw material lithium compound and lanthanum compound is eluted and the particle size is reduced, so that the time required for pulverization can be shortened.
By shortening the pulverization time in this way, it is possible to suppress the mixing of Al 2 O 3 and SiO 2 components when the alumina lining ball mill is used.
　なお、ボールミルのなかでも、ウレタンライニングボールミル、ナイロン製ボールミル、天然ゴムライニングボールミル等を用いることが好適である。これにより、アルミナライニングボールミルを用いる場合のＡｌ2Ｏ3及びＳｉＯ2成分の混入が抑制される。粉砕メディアには、ジルコニアメディア、アルミナメディアを用いることができる。 Among the ball mills, it is preferable to use a urethane lining ball mill, a nylon ball mill, a natural rubber lining ball mill, or the like. As a result, mixing of Al 2 O 3 and SiO 2 components when using an alumina lining ball mill is suppressed. As the pulverized media, zirconia media and alumina media can be used.
　第一湿式粉砕工程では、粉砕の後、スプレードライヤー乾燥機、流動層乾燥機、転動造粒乾燥機、凍結乾燥機または熱風乾燥機等を用いて乾燥する。なお、スプレードライヤー乾燥機を用いる場合、たとえば、熱風入口温度を２００～２５０℃、排風温度を９０～１２０℃とすることができる。これにより、第一粉砕粉末が得られる。 In the first wet pulverization step, after pulverization, it is dried using a spray dryer dryer, a fluidized bed dryer, a rolling granulation dryer, a freeze dryer, a hot air dryer, or the like. When a spray dryer / dryer is used, for example, the hot air inlet temperature can be set to 200 to 250 ° C. and the exhaust air temperature can be set to 90 to 120 ° C. As a result, the first pulverized powder is obtained.
　上記の第一粉砕粉末に対しては、必要に応じて所定の目開きの篩で篩別した後、１０００℃～１２００℃で１時間～１２時間にわたって加熱する仮焼工程を行う。仮焼工程では、酸素雰囲気もしくは大気雰囲気または、窒素等の不活性ガス雰囲気とすることができる。なお、仮焼後には、所定の目開きの篩にて篩別することができる。仮焼工程を経ることにより、仮焼粉末が得られる。 The above-mentioned first pulverized powder is sieved with a sieve having a predetermined opening as necessary, and then a calcining step of heating at 1000 ° C. to 1200 ° C. for 1 to 12 hours is performed. In the calcination step, an oxygen atmosphere, an air atmosphere, or an inert gas atmosphere such as nitrogen can be created. After the calcining, the sieve can be separated by a sieve having a predetermined opening. By going through the calcination step, the calcination powder is obtained.
　そして、仮焼粉末を、ボールミル等で溶媒を加えて粉砕する第二湿式粉砕工程を行う。第二湿式粉砕工程も、ボールミルに、純水とエタノール等のアルコールの混合溶媒及び、必要に応じて界面活性剤等の分散媒を投入して行われる。またここでも、アルミナライニングボールミル、ウレタンライニングボールミル、ナイロン製ボールミル、天然ゴムライニングボールミルを用いることができる。粉砕メディアはジルコニアメディア、アルミナメディアを用いることができる。ボールミルによる湿式粉砕に加えて又は代えて、ビーズミルによる湿式粉砕を行ってもよい。なお、粉砕時間は１時間～６時間とすることができる。また、粉砕後は、第一湿式粉砕工程と同様にして乾燥することができる。第二湿式粉砕工程では第二粉砕粉末が得られる。 Then, a second wet pulverization step is performed in which the calcined powder is pulverized by adding a solvent with a ball mill or the like. The second wet pulverization step is also carried out by charging a ball mill with a mixed solvent of pure water and alcohol such as ethanol and, if necessary, a dispersion medium such as a surfactant. Also here, an alumina lining ball mill, a urethane lining ball mill, a nylon ball mill, and a natural rubber lining ball mill can be used. As the pulverized media, zirconia media and alumina media can be used. In addition to or instead of wet pulverization by a ball mill, wet pulverization by a bead mill may be performed. The crushing time can be 1 hour to 6 hours. Further, after pulverization, it can be dried in the same manner as in the first wet pulverization step. In the second wet pulverization step, a second pulverized powder is obtained.
　しかる後は、第二粉砕粉末に対して乾式粉砕工程を行うことができる。ここでは、ボールミル等を用いて第二粉砕粉末を乾式で粉砕し、第三粉砕粉末とする。ボールミルとしては、アルミナライニングボールミル、ウレタンライニングボールミル、ナイロン製ボールミル、天然ゴムライニングボールミル等を、また粉砕メディアとしては、ジルコニアメディア、アルミナメディア等をそれぞれ用いることができる。粉砕時間は、たとえば２時間～１０時間とする。但し、乾式粉砕工程は省略することもある。 After that, the dry crushing step can be performed on the second crushed powder. Here, the second pulverized powder is pulverized by a dry method using a ball mill or the like to obtain a third pulverized powder. As the ball mill, an alumina lining ball mill, a urethane lining ball mill, a nylon ball mill, a natural rubber lining ball mill and the like can be used, and as the crushing medium, a zirconia media, an alumina media and the like can be used. The crushing time is, for example, 2 hours to 10 hours. However, the dry crushing step may be omitted.
　さらにその後、必要に応じて、第二粉砕粉末又は第三粉砕粉末を微粒子化する微粒子化工程を行うことができる。微粒子化工程を行った場合、第二粉砕粉末又は第三粉砕粉末は粉砕ないし解砕されて、より粒径が小さくなる。微粒子化工程では、乾式もしくは湿式のジェットミル、ボールミル又はビーズミル等を用いることができるが、なかでも、ジェットミルが粉砕効率の点で好ましい。
　上記の乾式粉砕工程の後、又は、微粒子化工程の後、先に述べたような酸化物系固体電解質が得られる。 After that, if necessary, a micronization step of micronizing the second pulverized powder or the third pulverized powder can be performed. When the micronization step is performed, the second pulverized powder or the third pulverized powder is pulverized or crushed to have a smaller particle size. In the micronization step, a dry or wet jet mill, ball mill, bead mill or the like can be used, and among them, the jet mill is preferable in terms of pulverization efficiency.
After the above-mentioned dry pulverization step or after the fine particle-forming step, the oxide-based solid electrolyte as described above is obtained.
（二次電池）
　以上に述べた酸化物系固体電解質を用いて、二次電池を作製することができる。ここでいう二次電池は、充電可能であって繰返し使用できる蓄電池を意味し、液体電解質を用いたものや、固体電解質を用いたものが含まれる。液体電解質を用いた二次電池では、正極や負極を改善する目的で、上記の酸化物系固体電解質を混ぜ込むことがある。酸化物系固体電解質は典型的には、固体電解質を含む全固体電池に好適に用いられ得る。 (Secondary battery)
A secondary battery can be manufactured by using the oxide-based solid electrolyte described above. The secondary battery referred to here means a storage battery that is rechargeable and can be used repeatedly, and includes a battery that uses a liquid electrolyte and a battery that uses a solid electrolyte. In a secondary battery using a liquid electrolyte, the above-mentioned oxide-based solid electrolyte may be mixed in for the purpose of improving the positive electrode and the negative electrode. Oxide-based solid electrolytes can typically be suitably used for all-solid-state batteries containing solid electrolytes.
　全固体電池は、たとえば、少なくとも、正極活物質粒子を層状に配置した正極層と、負極活物質粒子を層状に配置した負極層と、正極層及び負極層の間に位置し、酸化物系固体電解質を層状に配置した固体電解質層とを有することがある。正極層や負極層内には、一部の酸化物系固体電解質が存在し得る。なお一般に、全固体電池は、正極層及び負極層のそれぞれの外側に、それらの正極層、固体電解質層及び負極層を両側から挟むように設けられる集電体をさらに有する。このような全固体電池は、真空蒸着法等の気相法により薄膜を積層させて形成される薄膜型の全固体電池と区別して、バルク型の全固体電池と称されることがある。 The all-solid-state battery is located, for example, between at least a positive electrode layer in which positive electrode active material particles are arranged in layers, a negative electrode layer in which negative electrode active material particles are arranged in layers, and an oxide-based solid. It may have a solid electrolyte layer in which the electrolytes are arranged in layers. Some oxide-based solid electrolytes may be present in the positive electrode layer and the negative electrode layer. In general, an all-solid-state battery further has a current collector provided on the outside of each of the positive electrode layer and the negative electrode layer so as to sandwich the positive electrode layer, the solid electrolyte layer, and the negative electrode layer from both sides. Such an all-solid-state battery is sometimes referred to as a bulk-type all-solid-state battery to distinguish it from a thin-film type all-solid-state battery formed by laminating thin films by a vapor phase method such as a vacuum vapor deposition method.
　バルク型の全固体電池を作製する方法の一例としては、集電体の間に、正極活物質粒子、酸化物系固体電解質及び負極活物質粒子を層状に積層させる。そして、それらの正極活物質粒子、酸化物系固体電解質及び負極活物質粒子を、所定の温度に加熱して焼結させる。これにより、所要のイオン伝導率を発揮し得る全固体リチウムイオン電池等の全固体電池が得られる。なお、バルク型の全固体電池では、正極層や負極層内にも酸化物系固体電解質が焼結して配置され得るので、そこでのイオン伝導経路が確保されて、高い伝導率を有するものになる。この場合、固体電解質層のみならず正極層や負極層にも、焼成型固体電解質が存在する。 As an example of a method for producing a bulk type all-solid-state battery, positive electrode active material particles, oxide-based solid electrolyte, and negative electrode active material particles are laminated in layers between current collectors. Then, the positive electrode active material particles, the oxide-based solid electrolyte, and the negative electrode active material particles are heated to a predetermined temperature and sintered. As a result, an all-solid-state battery such as an all-solid-state lithium-ion battery capable of exhibiting the required ionic conductivity can be obtained. In the bulk type all-solid-state battery, the oxide-based solid electrolyte can be sintered and arranged in the positive electrode layer and the negative electrode layer, so that the ion conduction path there is secured and the battery has high conductivity. Become. In this case, the fired solid electrolyte exists not only in the solid electrolyte layer but also in the positive electrode layer and the negative electrode layer.
　仮に、酸化物系固体電解質が比較的高い温度で加熱しなければ焼結しないものであった場合、バルク型の全固体電池を作製する際に、当該酸化物系固体電解質を焼結させるべく高温に加熱することが必要になる。但し、層状に積層させた正極活物質粒子、酸化物系固体電解質及び負極活物質粒子を高温に加熱すると、正極活物質粒子や負極活物質粒子と酸化物系固体電解質とが反応し、正極層や負極層と固体電解質層との界面に、意図しない物質が生成して、イオン伝導率を低下させるおそれがある。
　これに対し、先に述べた実施形態の酸化物系固体電解質は低温焼結が可能になるので、バルク型の全固体電池に用いた場合に、各層の界面への、イオン伝導率を低下させ得る物質の生成を抑制することができる。それ故に、所要の電池性能を有するバルク型の全固体電池を有効に作製することができる。つまり、ここで述べた実施形態の酸化物系固体電解質は、全固体電池の焼成型固体電解質に好適に用いることができる。 If the oxide-based solid electrolyte is not sintered unless it is heated at a relatively high temperature, the temperature is high enough to sinter the oxide-based solid electrolyte when manufacturing a bulk-type all-solid-state battery. Needs to be heated. However, when the positive electrode active material particles, the oxide-based solid electrolyte, and the negative electrode active material particles laminated in layers are heated to a high temperature, the positive electrode active material particles and the negative electrode active material particles react with the oxide solid electrolyte, and the positive electrode layer Or, an unintended substance may be generated at the interface between the negative electrode layer and the solid electrolyte layer, which may reduce the ionic conductivity.
On the other hand, since the oxide-based solid electrolyte of the above-described embodiment enables low-temperature sintering, when used in a bulk-type all-solid-state battery, the ionic conductivity to the interface of each layer is lowered. The production of the obtained substance can be suppressed. Therefore, a bulk type all-solid-state battery having the required battery performance can be effectively manufactured. That is, the oxide-based solid electrolyte of the embodiment described here can be suitably used as a calcined solid electrolyte of an all-solid-state battery.
　次に、この発明の酸化物系固体電解質を試作し、その効果を確認したので以下に説明する。但し、ここでの説明は単なる例示を目的としたものであり、これに限定されることを意図するものではない。 Next, the oxide-based solid electrolyte of the present invention was prototyped and its effect was confirmed, which will be described below. However, the description here is for the purpose of mere illustration, and is not intended to be limited thereto.
（製造方法）
　原料として、炭酸リチウム（Ｓｏｃｉｅｄａｄ　Ｑｕｉｍｉｃａ　ｙ　Ｍｉｎｅｒａ　ｄｅ　Ｃｈｉｌｅ　Ｓ．Ａ．製、純度９９．２質量％以上）、酸化ランタン（宣興新威利成稀土有限公司製、純度９９．９９質量％以上）、酸化チタン（東邦チタニウム株式会社製、純度９９．９９質量％以上）を準備した。酸化チタンとしては、比較例１及び２では、平均粒径Ｄ５０が２．３μｍ、ＢＥＴ比表面積が２．０ｍ2／ｇであるものを、また実施例１及び２では、平均粒径Ｄ５０が０．８μｍ、ＢＥＴ比表面積が６．０ｍ2／ｇであるものをそれぞれ用いた。比較例３では、平均粒径Ｄ５０が２．２μｍ、ＢＥＴ比表面積が２．０ｍ2／ｇである酸化チタンを用いた。実施例３では、平均粒径Ｄ５０が０．８μｍ、ＢＥＴ比表面積が５．０ｍ2／ｇである酸化チタンを用いた。実施例４～６では、平均粒径Ｄ５０が２．２μｍ、ＢＥＴ比表面積が２．０ｍ2／ｇである酸化チタンを用いた。 (Production method)
As raw materials, lithium carbonate (manufactured by Sociedad Química y Minera de Chile SA, purity 99.2% by mass or more), lanthanum oxide (manufactured by Sociedad Química Rare Earth Co., Ltd., purity 99.99% by mass or more) Titanium oxide (manufactured by Toho Titanium Co., Ltd., purity 99.99% by mass or more) was prepared. As titanium oxide, in Comparative Examples 1 and 2, the average particle size D50 was 2.3 μm and the BET specific surface area was 2.0 m 2 / g, and in Examples 1 and 2, the average particle size D50 was 0. Those having a BET specific surface area of .8 μm and a BET specific surface area of 6.0 m 2 / g were used. In Comparative Example 3, titanium oxide having an average particle size D50 of 2.2 μm and a BET specific surface area of 2.0 m 2 / g was used. In Example 3, titanium oxide having an average particle size D50 of 0.8 μm and a BET specific surface area of 5.0 m 2 / g was used. In Examples 4 to 6, titanium oxide having an average particle size D50 of 2.2 μm and a BET specific surface area of 2.0 m 2 / g was used.
　上記の原料を秤量し、イオン交換水３５Ｌ及びエタノール３５Ｌならびに、アルミナメディア（径３ｍｍ）２００ｋｇとともに、ウレタンライニングボールミル（容量２００Ｌ）に投入した。そして、粉砕を３０分間行った後、当該ボールミル内で１５時間放置し、さらにその後、再度粉砕を３０分間行った。この粉砕後、スプレードライヤーにより乾燥し、第一粉砕粉末を得た。乾燥は、原料供給量：１０～３０Ｌ／ｈ、熱風入口温度：２００～２５０℃、排風温度：９０～１２０℃の条件とした。 The above raw materials were weighed and put into a urethane lining ball mill (capacity 200 L) together with 35 L of ion-exchanged water, 35 L of ethanol, and 200 kg of alumina media (diameter 3 mm). Then, after pulverizing for 30 minutes, it was left in the ball mill for 15 hours, and then pulverized again for 30 minutes. After this pulverization, it was dried by a spray dryer to obtain a first pulverized powder. Drying was carried out under the conditions of raw material supply amount: 10 to 30 L / h, hot air inlet temperature: 200 to 250 ° C., and exhaust air temperature: 90 to 120 ° C.
　次いで、第一粉砕粉末をコウジライトムライト材質の匣鉢内に投入し、電気炉にて仮焼を行った。仮焼条件は、大気雰囲気、仮焼温度：１１５０℃、仮焼時間：２時間とした。 Next, the first crushed powder was put into a saggar made of Kojilite mullite material and calcined in an electric furnace. The calcining conditions were air atmosphere, calcining temperature: 1150 ° C., and calcining time: 2 hours.
　その後、仮焼で得られた仮焼粉末７０ｋｇを、イオン交換水６０Ｌ及び、分散剤としてのポリアクリル酸アンモニウム塩７００ｇならびに、ジルコニアメディア（径３ｍｍ）２００ｋｇとともに、ウレタンライニングボールミル（容量２００Ｌ）に投入し、粉砕を６時間行った。粉砕後、アクリル樹脂系バインダー４．５ｋｇを投入し、１５分間混合を行った。その後、スプレードライヤーにより乾燥し、第二粉砕粉末を得た。乾燥は、原料供給量：１０～３０Ｌ／ｈ、熱風入口温度：２００～２５０℃、排風温度：９０～１２０℃の条件とした。 Then, 70 kg of the calcined powder obtained by calcining was put into a urethane lining ball mill (capacity 200 L) together with 60 L of ion-exchanged water, 700 g of ammonium polyacrylate as a dispersant, and 200 kg of zirconia media (diameter 3 mm). And crushed for 6 hours. After pulverization, 4.5 kg of an acrylic resin-based binder was added and mixed for 15 minutes. Then, it was dried by a spray dryer to obtain a second pulverized powder. Drying was carried out under the conditions of raw material supply amount: 10 to 30 L / h, hot air inlet temperature: 200 to 250 ° C., and exhaust air temperature: 90 to 120 ° C.
　そして、第二粉砕粉末を、アルミナメディアとともにテフロンライニングボールミル（「テフロン」は登録商標）に投入し、４時間にわたって乾式粉砕を行った。これにより、第三粉砕粉末を得た。 Then, the second pulverized powder was put into a Teflon lining ball mill (“Teflon” is a registered trademark) together with alumina media, and dry pulverization was performed for 4 hours. As a result, a third pulverized powder was obtained.
　その後、ジェットミル（（株）セイシン企業社製のＳＴＪ－２００）を用いて、第三粉砕粉末の微粒子化を行った。ジェットミルでの微粒子化の条件は、処理量１１ｋｇ／ｈｒ、プレッシャー圧力０．７ＭＰａ、グライディング圧力０．７ＭＰａとした。なお、比較例１及び実施例１では、この微粒子化を行わなかった。 After that, a jet mill (STJ-200 manufactured by Seishin Enterprise Co., Ltd.) was used to make the third pulverized powder into fine particles. The conditions for fine particle formation in the jet mill were a processing amount of 11 kg / hr, a pressure pressure of 0.7 MPa, and a gliding pressure of 0.7 MPa. In Comparative Example 1 and Example 1, this fine particle formation was not performed.
　実施例５及び実施例６では、仮焼粉末に対してボールミルによる湿式粉砕を行った後にさらに、ビーズミルによる湿式粉砕を行って第二粉砕粉末を得たこと、並びに、この第二粉砕粉末に対して微粒子化を行ったことを除いて、上述したところと実質的に同様にして酸化物系固体電解質を製造した。
　より詳細には、実施例５及び実施例６では、仮焼で得られた仮焼粉末４００ｇを、イオン交換水１．２Ｌ及び、分散剤としてのポリアクリル酸アンモニウム塩４ｇならびに、ジルコニアメディア（径３ｍｍ）５ｋｇとともに、ウレタンライニングボールミル（容量５Ｌ）に投入し、粉砕を１９時間行った。
　次いで、得られたスラリー１６００ｇを、ビーズミル（装置名：ＭＩＮＩＣｅｒ）で１時間にわたって湿式粉砕を行った。ビーズミルのメディアの径は、実施例５では０．３ｍｍとし、実施例６では０．１ｍｍとした。
　その後、スプレードライヤーにより乾燥し、第二粉砕粉末を得た。乾燥は、原料供給量：１０～３０Ｌ／ｈ、熱風入口温度：２００～２５０℃、排風温度：９０～１２０℃の条件とした。
　そして、実施例５及び６では乾式粉砕を省略し、この第二粉砕粉末に対して、上記と同様の条件でジェットミルによる微粒子化を行った。 In Examples 5 and 6, the calcined powder was wet-pulverized with a ball mill and then wet-pulverized with a bead mill to obtain a second pulverized powder, and the second pulverized powder was obtained. An oxide-based solid electrolyte was produced in substantially the same manner as described above, except that the particles were pulverized.
More specifically, in Examples 5 and 6, 400 g of the calcined powder obtained by calcining, 1.2 L of ion-exchanged water, 4 g of ammonium polyacrylate as a dispersant, and zirconia media (diameter). It was put into a urethane lining ball mill (capacity 5 L) together with 5 kg (3 mm) and pulverized for 19 hours.
Next, 1600 g of the obtained slurry was wet-pulverized with a bead mill (device name: MINICEr) for 1 hour. The diameter of the media of the bead mill was 0.3 mm in Example 5 and 0.1 mm in Example 6.
Then, it was dried by a spray dryer to obtain a second pulverized powder. Drying was carried out under the conditions of raw material supply amount: 10 to 30 L / h, hot air inlet temperature: 200 to 250 ° C., and exhaust air temperature: 90 to 120 ° C.
Then, in Examples 5 and 6, dry pulverization was omitted, and the second pulverized powder was pulverized by a jet mill under the same conditions as described above.
（評価）
　上記のようにして得られた比較例１、２及び実施例１、２のそれぞれに対し、ＰＡＮａｌｙｔｉｃａｌ　Ｘ’ｐｅｒｔ　Ｐｒｏを用いて、粉末Ｘ線回折法を行い、それにより得られた各Ｘ線回折パターンについて、ＩＣＤＤデータベース（ＰＡＮａｌｙｔｉｃａｌ　Ｅｘａｍｐｌｅ　ＤａｔａｂａｓｅとＰＤＦ－４＋　２０１９ＲＤＢ）と照合した。比較例１のＸ線回折パターンを図１に、比較例２のＸ線回折パターンを図２に、実施例１のＸ線回折パターンを図３に、実施例２のＸ線回折パターンを図４にそれぞれ示す。粉末Ｘ線回折法及び同定は具体的には、先述した方法に基いて行った。
　その結果、比較例１、２及び実施例１、２はいずれも、Ｘ線回折パターン中に上記一般式（Ｉ）で表される化合物のＸ線回折パターンが存在していたことから、Ｌａ0.57Ｌｉ0.29ＴｉＯ3が含まれる酸化物系固体電解質であることが確認された。比較例３及び実施例３～６についても、図示は省略するがＸ線回折パターンより、Ｌａ0.57Ｌｉ0.29ＴｉＯ3が含まれる酸化物系固体電解質であることが確認された。 (Evaluation)
Powder X-ray diffraction method was performed on each of Comparative Examples 1 and 2 and Examples 1 and 2 obtained as described above using PANalytical X'pert Pro, and each X-ray diffraction obtained thereby was performed. The pattern was collated with the ICDD database (PANNalytical X-ray Database and PDF-4 + 2019RDB). The X-ray diffraction pattern of Comparative Example 1 is shown in FIG. 1, the X-ray diffraction pattern of Comparative Example 2 is shown in FIG. 2, the X-ray diffraction pattern of Example 1 is shown in FIG. 3, and the X-ray diffraction pattern of Example 2 is shown in FIG. Each is shown in. Specifically, the powder X-ray diffraction method and identification were performed based on the method described above.
As a result, in both Comparative Examples 1 and 2 and Examples 1 and 2, since the X-ray diffraction pattern of the compound represented by the above general formula (I) was present in the X-ray diffraction pattern, La 0.57 It was confirmed that it was an oxide-based solid electrolyte containing Li 0.29 TiO 3 . Although not shown, it was confirmed from the X-ray diffraction pattern that Comparative Example 3 and Examples 3 to 6 were oxide-based solid electrolytes containing La 0.57 Li 0.29 TiO 3 .
　また、比較例１～３及び実施例１～６の各酸化物系固体電解質の平均粒径Ｄ５０及びＢＥＴ比表面積をそれぞれ、先述した方法に基いて、ＬＡ－９２０及びマックソーブを用いて測定した。その結果、表１及び表２に示すように、比較例１の酸化物系固体電解質の平均粒径Ｄ５０は４１．９μｍ、ＢＥＴ比表面積は１．０ｍ2／ｇであった。比較例２の酸化物系固体電解質の平均粒径Ｄ５０は２０．０μｍ、ＢＥＴ比表面積は２．０ｍ2／ｇであった。比較例３の酸化物系固体電解質の平均粒径Ｄ５０は１．３μｍ、ＢＥＴ比表面積は２．０ｍ2／ｇであった。実施例１の酸化物系固体電解質の平均粒径Ｄ５０は１．０μｍ、ＢＥＴ比表面積は５．０ｍ2／ｇであった。実施例２の酸化物系固体電解質の平均粒径Ｄ５０は０．９μｍ、ＢＥＴ比表面積は５．０ｍ2／ｇであった。実施例３の酸化物系固体電解質の平均粒径Ｄ５０は１．０μｍ、ＢＥＴ比表面積は５．０ｍ2／ｇであった。実施例４の酸化物系固体電解質の平均粒径Ｄ５０は０．６μｍ、ＢＥＴ比表面積は１０．０ｍ2／ｇであった。実施例５の酸化物系固体電解質の平均粒径Ｄ５０は０．４μｍ、ＢＥＴ比表面積は２５．０ｍ2／ｇであった。実施例６の酸化物系固体電解質の平均粒径Ｄ５０は０．２μｍ、ＢＥＴ比表面積は３０．０ｍ2／ｇであった。 Further, the average particle size D50 and the BET specific surface area of each of the oxide-based solid electrolytes of Comparative Examples 1 to 3 and Examples 1 to 6 were measured using LA-920 and Macsorb based on the above-mentioned methods, respectively. As a result, as shown in Tables 1 and 2, the average particle size D50 of the oxide-based solid electrolyte of Comparative Example 1 was 41.9 μm, and the BET specific surface area was 1.0 m 2 / g. The average particle size D50 of the oxide-based solid electrolyte of Comparative Example 2 was 20.0 μm, and the BET specific surface area was 2.0 m 2 / g. The average particle size D50 of the oxide-based solid electrolyte of Comparative Example 3 was 1.3 μm, and the BET specific surface area was 2.0 m 2 / g. The average particle size D50 of the oxide-based solid electrolyte of Example 1 was 1.0 μm, and the BET specific surface area was 5.0 m 2 / g. The average particle size D50 of the oxide-based solid electrolyte of Example 2 was 0.9 μm, and the BET specific surface area was 5.0 m 2 / g. The average particle size D50 of the oxide-based solid electrolyte of Example 3 was 1.0 μm, and the BET specific surface area was 5.0 m 2 / g. The average particle size D50 of the oxide-based solid electrolyte of Example 4 was 0.6 μm, and the BET specific surface area was 10.0 m 2 / g. The average particle size D50 of the oxide-based solid electrolyte of Example 5 was 0.4 μm, and the BET specific surface area was 25.0 m 2 / g. The average particle size D50 of the oxide-based solid electrolyte of Example 6 was 0.2 μm, and the BET specific surface area was 30.0 m 2 / g.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　参考として、実施例１の酸化物系固体電解質のＳＥＭ画像を図５に示し、実施例２の酸化物系固体電解質のＳＥＭ画像を図６に示す。 For reference, the SEM image of the oxide-based solid electrolyte of Example 1 is shown in FIG. 5, and the SEM image of the oxide-based solid electrolyte of Example 2 is shown in FIG.
　また、比較例１～３及び実施例１～６の各酸化物系固体電解質を用いて、表３及び表４に示す各条件にて、一軸圧縮及び冷間等方圧加圧（ＣＩＰ）をこの順序で行い、成形体を得た。具体的には、０．５ｇの酸化物系固体電解質に対して４０ＭＰａの一軸圧縮を施して圧粉体を作製した。次いで、この圧粉体を冷間等方圧加圧装置に配置し、該圧粉体に対して２００ＭＰａの圧力で冷間等方圧加圧（ＣＩＰ）を行った。これにより、直径５ｍｍ、長さ１０ｍｍの円柱状の成形体を得た。
　それらの各成形体に対し、上述した熱機械分析装置（ＴＭＡ、リガク株式会社製ＴＭＡ８３１０）を使用して表３及び表４に示す条件で、空気中で加熱した。なお、本測定における到達温度は１３５０℃である。表３及び表４には、一軸圧縮、ＣＩＰ及びＴＭＡの各処理後に測定した各密度も示した（試験例１～１４）。なお、一軸圧縮にはＥＮＥＲＰＡＣ社製のＥＳＥ－４３３－００を、またＣＩＰにはエヌピーエーシステム（株）社製のＣＰＰ２８－３００Ｂをそれぞれ用いた。また、試験例４では、ＣＩＰ条件を１５０ＭＰａとした。 In addition, uniaxial compression and cold isotropic pressurization (CIP) were performed under the conditions shown in Tables 3 and 4 using the oxide-based solid electrolytes of Comparative Examples 1 to 3 and Examples 1 to 6. This was performed in this order to obtain a molded product. Specifically, 0.5 g of an oxide-based solid electrolyte was subjected to uniaxial compression of 40 MPa to prepare a green compact. Next, the green compact was placed in a cold isotropic pressurizing device, and cold isotropic pressurization (CIP) was performed on the green compact at a pressure of 200 MPa. As a result, a columnar molded body having a diameter of 5 mm and a length of 10 mm was obtained.
Each of these molded products was heated in air using the above-mentioned thermomechanical analyzer (TMA, TMA8310 manufactured by Rigaku Co., Ltd.) under the conditions shown in Tables 3 and 4. The ultimate temperature in this measurement is 1350 ° C. Tables 3 and 4 also show the densities measured after each treatment of uniaxial compression, CIP and TMA (Test Examples 1-14). ESE-433-00 manufactured by ENERAPAC was used for uniaxial compression, and CPP28-300B manufactured by NPA System Co., Ltd. was used for CIP. Further, in Test Example 4, the CIP condition was set to 150 MPa.
　ここで、試験例１～１４では、表３及び表４に示した条件によりＴＭＡで加熱した成形体の収縮率が０．１％に達したときの、各実施例及び各比較例の焼結開始温度とした。 Here, in Test Examples 1 to 14, sintering of each Example and each Comparative Example when the shrinkage rate of the molded product heated by TMA reached 0.1% under the conditions shown in Tables 3 and 4. The starting temperature was set.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
　表３及び表４から解かるように、実施例１～６の酸化物系固体電解質を用いた試験例３～９、１１～１４ではいずれも、特に焼結開始温度を９００℃以下に十分に低くすることができた。
　このことから、この発明の酸化物系固体電解質は、比較的低い温度で焼結できる可能性があることが示唆された。 As can be seen from Tables 3 and 4, in each of Test Examples 3 to 9 and 11 to 14 using the oxide-based solid electrolytes of Examples 1 to 6, the sintering start temperature was sufficiently set to 900 ° C. or lower. I was able to lower it.
From this, it was suggested that the oxide-based solid electrolyte of the present invention may be able to be sintered at a relatively low temperature.
　また、実施例２の酸化物系固体電解質のリチウムイオン伝導率を、以下の手順に沿って測定した。
　まず、１ＭのＬｉＣｌ水溶液を、１０ｍｍ角の２枚の濾紙に染み込ませ、厚さ２ｍｍの実施例２の酸化物系固体電解質のプレートの両面に張り付けた。実施例２の酸化物系固体電解質は１４ｍｍ角、濾紙は１０ｍｍ角で用意した。これを、ステンレス鋼からなる電極で挟み込んだ。ここでは、濾紙に染み込ませたＬｉＣｌ水溶液が、電解質として使われた。実施例２の酸化物系固体電解質の粒界の影響を明らかにするために、イオン伝導率は、１３ＭＨｚまで５Ｈｚの周波数レンジで、ＬＣＲメータ（ヒューレッドパッカード社製、ＨＰ４１９２Ａ）を用いたＡＣインピーダンス法で測定した。その結果、実施例２の酸化物系固体電解質のイオン伝導率は、５×１０-4Ｓ／ｃｍ（全体の抵抗４００Ω）であった。
　また、実施例２と同様にして、比較例２の酸化物系固体電解質のイオン伝導率を測定したところ、５×１０-4Ｓ／ｃｍ（全体の抵抗４００Ω）であった。 In addition, the lithium ion conductivity of the oxide-based solid electrolyte of Example 2 was measured according to the following procedure.
First, a 1 M aqueous solution of LiCl was impregnated into two 10 mm square filter papers and attached to both sides of a plate of the oxide-based solid electrolyte of Example 2 having a thickness of 2 mm. The oxide-based solid electrolyte of Example 2 was prepared in a 14 mm square shape, and the filter paper was prepared in a 10 mm square shape. This was sandwiched between electrodes made of stainless steel. Here, the LiCl aqueous solution impregnated in the filter paper was used as the electrolyte. In order to clarify the influence of the grain boundaries of the oxide-based solid electrolyte of Example 2, the ionic conductivity is the AC impedance using an LCR meter (HP4192A, manufactured by Hured Packard) in the frequency range of 5 Hz up to 13 MHz. Measured by method. As a result, the ionic conductivity of the oxide-based solid electrolyte of Example 2 was 5 × 10 -4 S / cm (overall resistance 400 Ω).
Further, when the ionic conductivity of the oxide-based solid electrolyte of Comparative Example 2 was measured in the same manner as in Example 2, it was 5 × 10 -4 S / cm (overall resistance 400 Ω).

Claims (3)

  1. 　下記一般式（Ｉ）
    　　Ａ2/3-xＬｉ3xＴｉＯ3　　　（Ｉ）
    　　（式中、ｘは、０．０４＜ｘ＜０．１４を満たし、Ａは、ランタノイドから選択される一種以上の元素である。）
    　で表される化合物を含み、平均粒径Ｄ５０が０．１μｍ～１．０μｍであり、ＢＥＴ比表面積が５．０ｍ2／ｇ～１００．０ｍ2／ｇであることを特徴とする酸化物系固体電解質。     The following general formula (I)
    A 2 / 3-x Li 3x TiO 3 (I)
    (In the formula, x satisfies 0.04 <x <0.14, and A is one or more elements selected from lanthanoids.)
    Comprising a compound represented by in a mean particle size D50 0.1 [mu] m ~ 1.0 .mu.m, oxide BET specific surface area is characterized by a 5.0m 2 /g~100.0m 2 / g Solid electrolyte.
  2. 　前記一般式（Ｉ）Ａ2/3-xＬｉ3xＴｉＯ3で表される化合物中のＡがＬａであることを特徴とする請求項１に記載の酸化物系固体電解質。 The oxide-based solid electrolyte according to claim 1, wherein A in the compound represented by the general formula (I) A 2 / 3-x Li 3x TiO 3 is La.
  3. 　焼結開始温度が９００℃以下であることを特徴とする請求項１または請求項２に記載の酸化物系固体電解質。 The oxide-based solid electrolyte according to claim 1 or 2, wherein the sintering start temperature is 900 ° C. or lower.
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Publication number Priority date Publication date Assignee Title
CN113517466A (en) * 2021-06-29 2021-10-19 浙江锋锂新能源科技有限公司 High-dispersion superfine solid electrolyte powder, preparation method and slurry dispersion method

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011119158A (en) * 2009-12-04 2011-06-16 Toyota Motor Corp Solid ionic conductor, solid electrolyte membrane, and all-solid lithium secondary battery
JP2012184138A (en) * 2011-03-04 2012-09-27 Seiko Epson Corp Method for producing lithium lanthanum titanate particle and lithium lanthanum titanate particle

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US9583786B2 (en) * 2013-11-26 2017-02-28 Lg Chem, Ltd. Secondary battery including solid electrolyte layer

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011119158A (en) * 2009-12-04 2011-06-16 Toyota Motor Corp Solid ionic conductor, solid electrolyte membrane, and all-solid lithium secondary battery
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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