WO2022193123A1 - Negative electrode material and preparation method therefor, electrochemical device, and electronic device - Google Patents
Negative electrode material and preparation method therefor, electrochemical device, and electronic device Download PDFInfo
- Publication number
- WO2022193123A1 WO2022193123A1 PCT/CN2021/081035 CN2021081035W WO2022193123A1 WO 2022193123 A1 WO2022193123 A1 WO 2022193123A1 CN 2021081035 W CN2021081035 W CN 2021081035W WO 2022193123 A1 WO2022193123 A1 WO 2022193123A1
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- WIPO (PCT)
- Prior art keywords
- negative electrode
- nitrogen
- electrode material
- carbon
- porous carbon
- Prior art date
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- 239000007773 negative electrode material Substances 0.000 title claims abstract description 174
- 238000002360 preparation method Methods 0.000 title claims abstract description 20
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Images
Classifications
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- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
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- H—ELECTRICITY
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- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
- H01M4/386—Silicon or alloys based on silicon
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
- H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/624—Electric conductive fillers
- H01M4/625—Carbon or graphite
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/027—Negative electrodes
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- 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 application relates to the technical field of anode materials, and in particular, to anode materials and preparation methods thereof, electrochemical devices and electronic devices.
- silicon-based anode materials have a gram capacity as high as 1500-4200 mAh/g, and are considered to be the most promising next-generation lithium-ion anode materials.
- silicon due to the low electrical conductivity of silicon (>10 8 ⁇ .cm), and its volume expansion of about 300% during charge-discharge and the formation of an unstable solid electrolyte interface (SEI), the silicon anode material in the charge-discharge process It will be pulverized and dropped from the current collector, causing the loss of electrical contact between the active material and the current collector, resulting in poor electrochemical performance, capacity decay, and cycle stability, which hinders its further application to a certain extent.
- SEI solid electrolyte interface
- Nano-sized silicon-based anode materials and dispersed in carbon matrix can effectively improve the cycle performance of silicon-based anode materials. After granulation, carbonization is carried out to obtain the silicon-carbon composite material that is mainly used now. However, the cycle performance of this anode material is low and the expansion rate is relatively large.
- the present application proposes a negative electrode material and a preparation method thereof, an electrochemical device and an electronic device.
- the negative electrode material can effectively alleviate the expansion of the negative electrode due to the expansion of the silicon base and graphite, thereby improving the cycle performance of the negative electrode material.
- the present application provides a negative electrode material, the negative electrode material includes an active material and a carbon layer on the surface of the active material, the active material includes nitrogen-doped porous carbon and a silicon-containing material layer; the negative electrode material
- the content of silicon in mass percentage is 30% to 80%.
- the silicon-containing material layer is located on the pore walls of the nitrogen-doped porous carbon.
- the negative electrode material satisfies at least one of the following conditions (1) to (4):
- the thickness D 0 of the silicon-containing material layer ranges from 1 nm to 10 nm;
- the porous carbon in the nitrogen-doped porous carbon has a wall thickness of 5 nm to 30 nm.
- the nitrogen-doped porous carbon satisfies at least one of the following conditions (1) to (3):
- the nitrogen-doped porous carbon has a specific surface area of 2000 m 2 /g to 3500 m 2 /g;
- the nitrogen-doped porous carbon has a pore volume of 1 cm 2 /g to 10 cm 2 /g;
- the average pore diameter of the pores in the nitrogen-doped porous carbon is 1 nm to 20 nm.
- the negative electrode material satisfies at least one of the following conditions (1) to (7):
- the specific surface area of the negative electrode material is 1 m 2 /g to 50 m 2 /g;
- the pore volume of the negative electrode material is 0.001 cm 2 /g to 0.1 cm 2 /g;
- the particle size of the negative electrode material ranges from 1um to 100um, and/or the average particle size of the negative electrode material is 2.5um to 50um;
- the powder conductivity of the negative electrode material is 2.0S/cm to 30S/cm;
- the thickness of the carbon layer of the negative electrode material is 2 nm to 20 nm;
- the mass percentage content of the carbon layer in the negative electrode material is 3% to 10%
- the mass percentage content of nitrogen-doped porous carbon in the negative electrode material is 10% to 67%.
- the value of IG ranges from 1.2 to 2.2.
- the nitrogen-doped porous carbon satisfies at least one of the following conditions (1) to (3):
- the nitrogen element in the nitrogen-doped porous carbon is doped in the carbon bulk phase in the form of C-N bonds;
- the configuration of nitrogen in the nitrogen-doped porous carbon includes at least one of pyridine-based nitrogen, pyrrole-based nitrogen, graphitic nitrogen, graphitized nitrogen, and oxide-based nitrogen, and the graphite Nitrogen makes up 30% to 70% of all nitrogen by mass.
- the present application provides a method for preparing the negative electrode material described in the first aspect, the method comprising the following steps:
- the antibiotic bacterial residue is subjected to high-temperature carbonization treatment and pickling treatment of metal salts to obtain nitrogen-doped porous carbon;
- the active material is mixed with a carbon source and then subjected to high temperature treatment to obtain a negative electrode material.
- the method satisfies at least one of the following conditions (1) to (3):
- the carbon source includes at least one of resin, pitch, and high molecular polymer
- (2) described metal salt includes at least one in sodium chloride, potassium chloride, sodium carbonate or potassium carbonate;
- the acid used in the pickling treatment includes at least one of hydrochloric acid, sulfuric acid, nitric acid, oxalic acid, hydrofluoric acid or phosphoric acid.
- the present application provides a negative electrode sheet, comprising a negative electrode current collector and a negative electrode active material layer disposed on the surface of the negative electrode current collector, the negative electrode active material layer comprising the negative electrode material described in the first aspect or the above
- the negative electrode material prepared by the preparation method described in the second aspect.
- the negative pole piece satisfies at least one of the following conditions (1) to (4):
- the porosity of the negative electrode active material layer is 20% to 40%
- the value range of the resistance of the negative electrode active material layer is 0.2 ⁇ to 2 ⁇ ;
- the compaction density of the negative electrode active material layer is 1.5g/cm 3 to 2.0g/cm 3 ;
- the OI value of the negative electrode active material layer ranges from 1 to 20.
- the present application provides an electrochemical device comprising a negative electrode active material layer, characterized in that the negative electrode active material layer comprises the negative electrode material described in the first aspect or the preparation method described in the second aspect above. obtained negative electrode material.
- the electrochemical device is a lithium-ion battery.
- the present application provides an electronic device comprising the electrochemical device of the fourth aspect.
- the present application at least has the following beneficial effects:
- the internal pores of nitrogen-doped porous carbon can alleviate a certain volume expansion ;
- the expansion of the silicon-containing material layer can be prevented from damaging the pore structure of the nitrogen-doped porous carbon and Carbon layer; can effectively alleviate the expansion of the negative electrode caused by the expansion of silicon material and graphite, thereby improving the cycle performance of the negative electrode active material and reducing the expansion efficiency of the battery.
- FIG. 1 is a schematic structural diagram of a negative electrode material provided in an embodiment of the present application.
- any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with any other lower limit to form an unspecified range, and likewise any upper limit can be combined with any other upper limit to form an unspecified range.
- every point or single value between the endpoints of a range is included within the range, even if not expressly recited.
- each point or single value may serve as its own lower or upper limit in combination with any other point or single value or with other lower or upper limits to form a range not expressly recited.
- an embodiment of the present application provides a negative electrode material.
- the negative electrode material includes an active material 10 and a carbon layer 20 on the surface of the active material, and the active material 10 includes nitrogen doping Porous carbon and silicon-containing material layer 11; the mass percentage content of silicon in the negative electrode material is 30% to 80%.
- the internal pores 12 of nitrogen-doped porous carbon can relieve a certain volume
- the expansion can effectively alleviate the expansion of the negative electrode caused by the expansion of the silicon material and the graphite, thereby improving the cycle performance of the negative electrode active material.
- the silicon-containing material layer is located on the pore walls of the nitrogen-doped porous carbon.
- nitrogen-doped porous carbon is used as the skeleton structure of the negative electrode material, so that the negative electrode material can provide more active sites for the attachment of lithium ions, thereby making the lithium ion battery have better charge-discharge cycle performance.
- the mass percentage content of silicon in the negative electrode material is 30% to 80%, specifically 30%, 32.4%, 44.3%, 52.5%, 60%, 65%, 70% or 80%, etc.
- Other values within the above range are also possible, which are not limited here. It is understandable that when the silicon content in the negative electrode material is too high, the expansion rate of the negative electrode material will be significantly increased, which will easily lead to the destruction of the negative electrode material structure, resulting in a decrease in the cycle performance of the battery; when the silicon content in the negative electrode material is too low, It will reduce the gram capacity of the negative electrode material and affect the capacity density of the negative electrode material.
- the mass percentage content of silicon in the negative electrode material is 32.4% to 52.5%.
- the thickness D 0 of the silicon-containing material layer ranges from 1 nm to 10 nm, specifically 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, or 10 nm, etc., of course, it can also be the above range Other values within are not limited here. If the thickness of the silicon-containing material layer is too small, the electrochemical performance of the material will decrease, and the battery capacity will decrease; if the thickness of the silicon-containing material layer is too large, the volume expansion effect of silicon will be more obvious, which will easily destroy the pore structure of nitrogen-doped porous carbon and the carbon layer. , which degrades the battery cycle performance. Preferably, the thickness D 0 of the silicon-containing material layer ranges from 5 nm to 10 nm.
- the average pore diameter D 1 of the pores in the nitrogen-doped porous carbon is 1 nm to 20 nm, specifically 1 nm, 2 nm, 3 nm, 5 nm, 8 nm, 10 nm, 12 nm, 15 nm, 18 nm or 20nm, etc., but are not limited to the recited values, and other unrecited values within the numerical range are also applicable.
- the average pore diameter D 1 of the pores in the nitrogen-doped porous carbon is 12 nm to 20 nm.
- the ratio range of the thickness D 0 of the silicon-containing material layer to the pore diameter D 1 of the nitrogen-doped porous carbon satisfies: 0.2 ⁇ D 0 /D 1 ⁇ 0.8, specifically 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, or 0.7, etc., of course, other values within the above range are also possible, which are not limited here.
- the thickness D 2 of the carbon layer of the negative electrode material is 2 nm to 20 nm, specifically 2 nm, 3 nm, 4 nm, 5 nm, 7 nm, 8 nm, 10 nm, 12 nm, 15 nm, 18 nm or 20 nm, etc. , and of course other values within the above range, which are not limited here.
- the carbon layer is too thick, the lithium ion transmission efficiency is reduced, which is not conducive to the high-rate charge and discharge of the material, and reduces the comprehensive performance of the negative electrode material; if the carbon layer is too thin, it is not conducive to increasing the conductivity of the negative electrode material and suppresses the volume expansion of the material. Weak performance, resulting in poor performance for long loops.
- the ratio range of the thickness D 0 of the silicon-containing material layer to the thickness D 2 of the carbon layer satisfies: 0.05 ⁇ D 0 /D 2 ⁇ 10, specifically 0.05, 0.1, 0.5, 1, 2, 3, 4 , 5, 6, 7, 8, 9, or 10, etc., of course, other values within the above range may also be used, which are not limited herein.
- the expansion of the silicon-containing material layer can be prevented from damaging the pores of the nitrogen-doped porous carbon. structure and carbon layer, thereby improving the cycle ability of the battery and reducing the expansion efficiency of the battery.
- the specific surface area of the nitrogen-doped porous carbon is 2000m 2 /g to 3500m 2 /g; specifically, it can be 2000m 2 /g, 2200m 2 /g, 2500m 2 /g, 2800m 2 /g, 3000m 2 /g or 3500m 2 /g, etc., but are not limited to the recited values, and other unrecited values within the range of values are also applicable.
- the pore volume of the nitrogen-doped porous carbon is 1 cm 2 /g to 10 cm 2 /g; specifically, it may be 1 cm 2 /g, 2 cm 2 /g, 3 cm 2 /g, 4 cm 2 /g, 5 cm 2 /g, 6 cm 2 /g, 8cm 2 /g, 9cm 2 /g or 10cm 2 /g, etc., but are not limited to the recited values, and other unrecited values within the range of values are also applicable.
- nitrogen-doped porous carbon has a large specific surface area and pore volume, which can facilitate the deposition of silicon-containing material layers in the pore structure of nitrogen-doped porous carbon, and the internal pores of nitrogen-doped porous carbon can alleviate certain problems. volume expansion.
- the wall thickness of the porous carbon in the nitrogen-doped porous carbon is 5 nm to 30 nm; Of course, other values within the above range are also possible, such as 30 nm, and are not limited here. Understandably, controlling the wall thickness of the porous carbon in the nitrogen-doped porous carbon within the above range can effectively improve the rigidity of the skeleton structure of the nitrogen-doped porous carbon as a negative electrode material, which is beneficial to improve the cycle performance of the material.
- the nitrogen element in the nitrogen-doped porous carbon is doped in the carbon bulk phase in the form of C-N bonds.
- the mass percentage content of nitrogen in the nitrogen-doped porous carbon is 0.5% to 10%, specifically 0.5%, 0.8%, 1%, 2%, 3%, 5%, 7%, 9% Or 10%, etc., of course, other values within the above range are also possible, which are not limited here.
- the configuration of nitrogen in the nitrogen-doped porous carbon includes at least one of pyridine nitrogen, pyrrole nitrogen, graphitic nitrogen, graphitized nitrogen and oxide nitrogen and the mass proportion of the graphitized nitrogen in all nitrogen is 30% to 70%, specifically 30%, 40%, 50%, 60% or 70%, etc.
- the mass percentage content of nitrogen-doped porous carbon in the negative electrode material is 10% to 67%, specifically 10%, 20%, 25%, 30%, 35%, 40% %, 50% or 67%, etc., of course, other values within the above range can also be used, which are not limited here.
- the mass percentage content of the carbon layer in the negative electrode material is 3% to 10%, specifically 3%, 4%, 5%, 6%, 7%, 8%, 9% % or 10%, etc., of course, other values within the above range are also possible, which are not limited here.
- the specific surface area of the negative electrode material is 1 m 2 /g to 50 m 2 /g, specifically 1 m 2 /g, 5 m 2 /g, 10 m 2 /g, 15 m 2 /g, 20m 2 /g, 25m 2 /g, 30m 2 /g, 40m 2 /g, 49m 2 /g or 50m 2 /g, etc., but not limited to the recited values, other unrecited values within the range of values The same applies.
- the specific surface area of the negative electrode material is within the above range, which ensures the processing performance of the material, is conducive to improving the primary efficiency of the lithium battery made of the negative electrode material, and is conducive to improving the cycle performance of the negative electrode material.
- the specific surface area of the negative electrode material is 2.1 m 2 /g to 5.2 m 2 /g.
- the pore volume of the negative electrode material is 0.001 cm 2 / g to 0.1 cm 2 / g ; 0.03cm 2 /g, 0.05cm 2 /g, 0.06cm 2 /g, 0.08cm 2 /g, 0.09cm 2 / g or 0.1cm 2 /g, etc., but not limited to the enumerated numerical values, the numerical range The same applies to other values not listed here.
- the smaller pore volume of the negative electrode material indicates that the surface of the outer carbon layer has less pore structure, and the active material of the inner core is well combined, which is beneficial to isolate the contact between the active material of the inner core and the electrolyte, and form a stable SEI film. Provides stable cycle performance.
- the particle size of the negative electrode material ranges from 1um to 100um, specifically 1um, 5um, 10um, 15um, 20um, 30um, 40um, 50um, 60um, 70um, 80um, 90um or 100um etc., but are not limited to the recited values, other non-recited values within the range of values also apply.
- the average particle size D50 of the negative electrode material is 2.5um to 50um.
- the powder conductivity of the negative electrode material is 2.0S/cm to 30S/cm, specifically 2.0S/cm, 2.5S/cm, 3.0S/cm, 5.0S/cm, 8.0S/cm, 10S/cm, 15S/cm, 20S/cm, 25S/cm or 30S/cm, etc., but not limited to the recited values, and other unrecited values within the range of values are also applicable.
- the value of the ratio ID / IG of the peak intensity ID at 1350 cm ⁇ 1 to the peak intensity IG at 1580 cm ⁇ 1 of the negative electrode material The range is 1.2 to 2.2 ; the value of ID / IG can be specifically 1.2, 1.4, 1.5, 1.8, 1.9, 2.0 or 2.2, etc., but is not limited to the listed values, and other unlisted values within the range of values The same applies to numerical values.
- the ratio is too high, it means that the surface defect of the negative electrode material is high, which will increase the formation of solid electrolyte (SEI) film, consume more lithium ions, and reduce the first efficiency of the battery.
- SEI solid electrolyte
- the ratio is too low, the kinetic performance of the anode material decreases.
- the present application provides a method for preparing a negative electrode material, the method comprising the following steps:
- step S10 nitrogen-doped porous carbon is obtained by subjecting the antibiotic bacterial residue to high-temperature carbonization treatment and pickling treatment of metal salts;
- Step S20 using silane gas to vapor-deposit the nitrogen-doped porous carbon to obtain an active material
- step S30 the active material is mixed with the carbon source and then subjected to high temperature treatment to obtain a negative electrode material.
- the thermal decomposition of silicon source gas is used to deposit silicon into nitrogen-doped porous carbon, which can effectively alleviate the expansion of the negative electrode due to the expansion of the silicon base and graphite, and can effectively improve the cycle performance of the negative electrode active material.
- step S10 nitrogen-doped porous carbon is obtained by subjecting the antibiotic bacterial residue to high-temperature carbonization treatment and pickling treatment of metal salts.
- the mass ratio of the antibiotic slag to the metal salt is (0.1 ⁇ 2):1, specifically 0.1:1, 0.3:1, 0.5:1, 0.8:1, 1:1 1, 1.2:1, 1.5:1, 1.8:1 or 2:1, etc.
- mass ratio of the antibiotic slag to the metal salt is (0.1 ⁇ 2):1, specifically 0.1:1, 0.3:1, 0.5:1, 0.8:1, 1:1 1, 1.2:1, 1.5:1, 1.8:1 or 2:1, etc.
- other values within the above range are also possible.
- the antibiotic slag and metal salt were put into deionized water, stirred evenly, and then placed in an oven at 110°C for drying.
- the metal salt includes at least one of sodium chloride, potassium chloride, sodium carbonate or potassium carbonate.
- the temperature of the high-temperature carbonization treatment is 600°C to 1000°C, specifically 600°C, 700°C, 800°C, 900°C, 950°C or 1000°C, etc., of course, it can also be the above range other values within.
- Control the heating rate from 1°C/min to 10°C/min, specifically 1°C/min, 2°C/min, 3°C/min, 4°C/min, 5°C/min, 6°C/min, 7°C/min min, 8° C./min, or 10° C./min, etc., of course, other values within the above-mentioned range are also possible.
- the holding time of the high-temperature carbonization treatment is 1h to 3h, specifically 1h, 1.5h, 2h, 2.5h or 3h, etc., of course, other values within the above range are also possible.
- a nitrogen-doped carbon material containing metal elements can be obtained by high-temperature carbonization.
- the metal element in the nitrogen-doped carbon material is subjected to acid washing treatment, so that the metal element is dissolved in the acid solution, so that the nitrogen-doped carbon material forms a porous structure.
- the acid used in the pickling treatment includes at least one of hydrochloric acid, sulfuric acid, nitric acid, oxalic acid, hydrofluoric acid or phosphoric acid.
- Step S20 vapor-depositing the nitrogen-doped porous carbon with silane gas to obtain an active material.
- the temperature of the vapor deposition is 400°C to 600°C, specifically 400°C, 450°C, 500°C, 550°C, or 600°C, etc., of course, other temperatures within the above range are also possible. value.
- the deposition time of the vapor deposition is 0.5h to 3h, specifically 0.5h, 1h, 1.5h, 2h, 2.5h or 3h, etc. Of course, it can also be other within the above range value.
- nitrogen-doped porous carbon is vapor-deposited with silane gas under the protection of inert gas.
- the volume ratio of the silane gas in the inert gas is 2% to 6%, specifically 2%, 3%, 4%, 5%, or 6%, etc., of course, other values within the above-mentioned range are also possible.
- step S30 the active material is mixed with a carbon source and then carbon composite treatment is performed to obtain a negative electrode material.
- the carbon source includes at least one of resin, pitch, and high molecular polymer.
- the active material and carbon source can be dispersed in a liquid phase system (for example, water), stirred and mixed well, and then dried, and the dried mixture is subjected to carbon composite treatment.
- a liquid phase system for example, water
- the temperature of the carbon composite treatment is 500°C to 1200°C, specifically 500°C, 550°C, 600°C, 700°C, 800°C, 900°C, 1000°C, 1100°C or Of course, other values within the above-mentioned range are also possible, such as 1200°C. Control the heating rate from 1°C/min to 10°C/min, specifically 1°C/min, 2°C/min, 3°C/min, 4°C/min, 5°C/min, 6°C/min, 7°C/min min, 8° C./min, or 10° C./min, etc., of course, other values within the above-mentioned range are also possible.
- the carbon composite treatment time is 1h to 24h; specifically, it can be 1h, 2h, 6h, 12h, 18h or 24h, etc., of course, it can also be other values within the above range.
- the carbon composite treatment is performed under the protection of an inert gas
- the inert gas can be, for example, at least one of nitrogen, argon, helium, krypton and the like.
- an embodiment of the present application provides a negative electrode sheet, the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer on the negative electrode current collector, the negative electrode active material layer comprises the negative electrode active material layer according to the first aspect of the present application negative electrode material.
- the negative electrode active material layer includes a binder
- the binder includes polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide-containing polymers, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylic The (esterified) styrene-butadiene rubber, epoxy resin, nylon, etc., are not limited here.
- the negative electrode active material layer further includes a conductive material
- the conductive material includes natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, metal powder, metal fiber, copper, nickel, aluminum , silver or polyphenylene derivatives, etc., are not limited here.
- the negative electrode current collector includes, but is not limited to: copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, foamed copper or a polymer substrate coated with conductive metal.
- the porosity of the negative electrode active material layer is 20% to 40%, specifically 20%, 23%, 25%, 28%, 30%, 33%, 35%, 38% % or 40%, and of course other values within the above range are also possible.
- the value range of the resistance of the negative electrode active material layer is 0.2 ⁇ to 2 ⁇ , specifically 0.2 ⁇ , 0.5 ⁇ , 0.8 ⁇ , 1 ⁇ , 1.2 ⁇ , 1.5 ⁇ , 1.8 ⁇ or 2 ⁇ , etc., of course, other values within the above range are also possible.
- the compaction density of the negative electrode active material layer is 1.5g/cm 3 to 2.0g/cm 3 , specifically 1.5g/cm 3 , 1.6g/cm 3 3 , 1.7 g/cm 3 , 1.8 g/cm 3 , 1.9 g/cm 3 or 2.0 g/cm 3 , etc., of course, other values within the above range are also possible.
- the OI value of the negative electrode active material layer ranges from 1 to 20, specifically 1, 3, 5, 8, 10, 13, 15, 18 or 20, etc. Of course, Other values within the above ranges are also possible.
- the present application further provides an electrochemical device, comprising a negative electrode active material layer, the negative electrode active material layer comprising the negative electrode material described in the first aspect or the method for preparing the negative electrode material described in the second aspect above. obtained negative electrode material.
- the electrochemical device further includes a positive electrode plate, and the positive electrode plate includes a positive electrode current collector and a positive electrode active material layer located on the positive electrode current collector.
- the positive active material includes at least one of lithium cobalt oxide (LiCoO2), lithium nickel manganese cobalt ternary material, lithium iron phosphate, lithium manganese iron phosphate, and lithium manganate.
- LiCoO2 lithium cobalt oxide
- LiN lithium nickel manganese cobalt ternary material
- iron phosphate lithium manganese iron phosphate
- manganate lithium manganate
- the positive electrode active material layer further includes a binder and a conductive material.
- the binder improves the bonding of the positive electrode active material particles to each other, and also improves the bonding of the positive electrode active material to the current collector.
- the binder includes polyvinyl alcohol, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide-containing polymers, polyvinylpyrrolidone , at least one of polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylic (esterified) styrene-butadiene rubber, epoxy resin or nylon.
- the conductive material includes carbon-based materials, metal-based materials, conductive polymers, and mixtures thereof.
- the carbon-based material is selected from natural graphite, artificial graphite, carbon black, acetylene black, ketjen black, carbon fiber, or any combination thereof.
- the metal-based material is selected from metal powders, metal fibers, copper, nickel, aluminum, or silver.
- the conductive polymer is a polyphenylene derivative.
- the positive electrode current collector includes, but is not limited to, aluminum foil.
- the electrochemical device further includes an electrolyte, and the electrolyte includes an organic solvent, a lithium salt and an additive.
- the organic solvent of the electrolytic solution according to the present application may be any organic solvent known in the prior art that can be used as a solvent of the electrolytic solution.
- the electrolyte used in the electrolyte solution according to the present application is not limited, and it may be any electrolyte known in the prior art.
- the additive for the electrolyte according to the present application may be any additive known in the art as an additive for the electrolyte.
- the organic solvent includes, but is not limited to: ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC), propylene carbonate or ethyl propionate.
- the lithium salt includes at least one of an organic lithium salt or an inorganic lithium salt.
- the lithium salts include, but are not limited to: lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), lithium difluorophosphate (LiPO 2 F 2 ), bistrifluoromethanesulfonimide Lithium LiN(CF 3 SO 2 ) 2 (LiTFSI), Lithium Bis(fluorosulfonyl)imide Li(N(SO 2 F) 2 )(LiFSI), Lithium Bisoxalate Borate LiB(C 2 O 4 ) 2 (LiBOB) ) or lithium difluorooxalate borate LiBF 2 (C 2 O 4 ) (LiDFOB).
- LiPF 6 lithium hexafluorophosphate
- LiBF 4 lithium tetrafluoroborate
- LiPO 2 F 2 lithium difluorophosphate
- LiPFSI bistrifluoromethanesulfonimide Lithium LiN(CF 3 SO
- the concentration of the lithium salt in the electrolyte may be 0.5 mol/L to 3 mol/L.
- the electrochemical device of the present application includes, but is not limited to: all kinds of primary batteries, secondary batteries, fuel cells, solar cells or capacitors.
- the electrochemical device is a lithium secondary battery, wherein the lithium secondary battery includes, but is not limited to, a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery, or a lithium ion secondary battery polymer secondary battery.
- an embodiment of the present application further provides an electronic device, where the electronic device includes the electrochemical device described in the fourth aspect.
- the electronic devices include, but are not limited to: notebook computers, pen input computers, mobile computers, e-book players, portable telephones, portable fax machines, portable copiers, portable printers, headsets, etc. stereo headphones, VCRs, LCD TVs, portable cleaners, portable CD players, mini discs, transceivers, electronic notepads, calculators, memory cards, portable recorders, radios, backup power, motors, cars, motorcycles, power Bicycles, bicycles, lighting equipment, toys, game consoles, clocks, power tools, flashlights, cameras, large household batteries or lithium-ion capacitors, etc.
- lithium ion batteries The preparation of lithium ion batteries is described below by taking lithium ion batteries as an example and in conjunction with specific embodiments. Those skilled in the art will understand that the preparation methods described in this application are only examples, and any other suitable preparation methods are included in the scope of this application. within the range.
- the solid substance is put into an acid solution with a concentration of 1 mol/L to 3 mol/L, pickled, and kept stirring for 1 h to 24 h, and then filtered to remove metal impurities to obtain nitrogen-doped porous carbon.
- the nitrogen-doped porous carbon is placed in a tube furnace, and in an inert atmosphere, silane vapor deposition is performed at 400° C.-600° C., the deposition time is 0.5h-3h, and the silane concentration is 2%-6% to obtain active material.
- Disperse the active material and an appropriate amount of carbon source in the liquid phase system keep stirring in a shear mixer for 0.5h-12h, mix evenly, and after drying, sinter in an inert atmosphere, and the sintering temperature is 500°C-1200°C, The heating rate is 1°C/min-10°C/min, and the holding time is 1h-24h.
- Examples 1 to 9 were prepared according to the above method, and the specific parameters of Examples 1 to 9 are shown in Table 1 below.
- Comparative Example 1 was prepared according to the above method, and the aspect ratio of the porous carbon fiber skeleton prepared in Comparative Example 1 was 1.0.
- the specific parameters of Comparative Example 1 are shown in Table 1 below.
- the negative electrode material, conductive carbon black and polymer were added with deionized water according to the mass ratio of 80:10:10, stirred into a slurry, coated with a scraper to form a coating with a thickness of 100um, and dried in a vacuum drying oven at 85°C for 12 hours.
- a punching machine in a dry environment to cut into 1 cm diameter circles, in a glove box metal lithium sheets were used as counter electrodes, ceglad composite membranes were selected as separators, and an electrolyte solution was added to assemble a button battery.
- Use the LAND series battery test test to test the charge and discharge of the battery to test its charge and discharge performance.
- the adsorption amount of the sample monolayer is calculated based on the Brownnauer-Etter-Taylor adsorption theory and its formula (BET formula), and then calculate The specific surface area of a solid.
- the carbon content test is performed on the sample first, and the value obtained by subtracting the test from 100% is the silicon content percentage. Among them, the carbon content test is as follows:
- the negative electrode material sample is heated and combusted by a high-frequency furnace under oxygen-enriched conditions to oxidize carbon and sulfur into carbon dioxide and sulfur dioxide.
- signal of. This signal is sampled by the computer, converted into a value proportional to the concentration of carbon dioxide and sulfur dioxide after linear correction, and then the value of the whole analysis process is accumulated. After the analysis, the accumulated value is divided by the weight value in the computer, and then multiplied by Correction coefficient, subtract the blank, you can obtain the percentage of carbon and sulfur in the sample.
- Samples were tested using a high-frequency infrared carbon-sulfur analyzer (Shanghai Dekai HCS-140).
- the nitrogen element content was measured using the CN 802 carbon and nitrogen element analyzer produced by Italian VELP Company, and the TCD detector was used as the N element detector.
- the Raman spectrum was measured using a Jobin Yvon LabRAM HR spectrometer with a light source of 532 nm and a test range of 0 cm -1 to 4000 cm -1 .
- the test range is 100 ⁇ m*100 ⁇ m, and the average value of ID / IG is obtained by counting 100 ID / IG values .
- the XPS test equipment is ESCLAB 250Xi from Thermo Fisher Scientific, with Al as the target as the excitation source, the power is 250w, and the vacuum degree is more than 10-9Pa.
- the configuration of nitrogen in nitrogen-doped porous carbon was determined by XPS testing.
- the cross-section polisher uses an ion source to ionize an inert gas to generate inert ions. After acceleration and focusing, the high-speed inert ions knock out atoms or molecules on the surface of the sample to achieve ion polishing. After being cut by CP, the sample was placed on the SEM special sample stage for SEM test. The instrument model is IB-09010CP, the ion accelerating voltage is 2-6kV, and the gas used is argon. After the silicon carbon anode material is cut through the cross section test, the thickness D 0 of the silicon-containing material layer, the thickness D 2 of the outer carbon layer and the wall thickness of the porous carbon at the cross section can be tested.
- Test method (4) is used to measure the silicon content in the silicon-carbon core without carbon compounding, that is, to obtain the mathematical relationship between the mass content of silicon and the mass content of nitrogen-doped porous carbon, and then use the same method to measure the negative electrode material.
- the mass percentage content of silicon in the middle is combined with the mass percentage content relationship between silicon and nitrogen-doped porous carbon, that is, the mass percentage content of the carbon layer is obtained.
- Test method (4) is used to measure the silicon content in the silicon-carbon core without carbon compounding, that is, to obtain the mathematical relationship between the mass content of silicon and the mass content of nitrogen-doped porous carbon, and then use the same method to measure the negative electrode material.
- the mass percentage content of silicon in the medium is combined with the mass percentage content relationship between silicon and nitrogen-doped porous carbon to obtain the mass percentage content of the doped porous carbon.
- the negative electrode materials, graphite, conductive agent (conductive carbon black, Super ) and binder PAA are mixed according to the weight ratio of 70:15:5:10, deionized water is added, and the negative electrode slurry is obtained under the action of a vacuum mixer; the negative electrode slurry is uniformly coated on the negative electrode current collector copper foil; The copper foil is dried, and then subjected to cold pressing, cutting, and slitting under a pressure of 5t, and then dried under vacuum conditions to obtain a negative pole piece.
- the compaction density of the negative electrode active material layer PD m/V
- m represents the weight of the negative electrode active material layer
- V represents the volume of the negative electrode active material layer
- m can be obtained by weighing with an electronic balance with an accuracy of more than 0.01g
- the negative electrode active material The product of the surface area and thickness of the layer is the volume V of the negative active material layer, where the thickness can be measured using a screw micrometer with an accuracy of 0.5 ⁇ m.
- X'pert PRO X-ray powder diffractometer
- the resistance of the negative electrode active material layer is measured by the four-point probe method.
- the instrument used in the four-point probe method is a precision DC voltage and current source (SB118 type).
- SB118 type precision DC voltage and current source
- Four copper plates with a length of 1.5cm*width of 1cm*2mm of thickness are fixed on a line at equal distances. Above, the distance between the two middle copper plates is L (1-2cm), and the base material for fixing the copper plates is an insulating material.
- the copper plates at both ends are connected to the DC current I, and the voltage V is measured on the two copper plates in the middle, and the values of I and V are read three times. , take the average values Ia and Va of I and V respectively, and the value of Va/Ia is the resistance of the negative electrode active material layer at the test place. Take 12 test points for each negative pole piece and take the average value
- the positive active material lithium cobalt oxide (LiCoO 2 ), conductive carbon black, and binder polyvinylidene fluoride are mixed according to the weight ratio of 95:2.5:2.5, and N-methylpyrrolidone (NMP) is added.
- NMP N-methylpyrrolidone
- the negative electrode materials, graphite, conductive agent (conductive carbon black, Super ) and binder PAA are mixed according to the weight ratio of 70:15:5:10, deionized water is added, and the negative electrode slurry is obtained under the action of a vacuum mixer; the negative electrode slurry is uniformly coated on the negative electrode current collector copper foil; The copper foil is dried, then subjected to cold pressing, cutting and slitting, and then dried under vacuum conditions to obtain a negative pole piece.
- a polyethylene porous polymer film is used as the separator.
- the positive pole piece, the separator and the negative pole piece in order, so that the separator is placed between the positive and negative pole pieces to play the role of isolation, and then roll up to obtain a bare cell; after welding the tabs, place the bare cell on the In the outer packaging foil aluminum-plastic film, the above-prepared electrolyte is injected into the dried bare cell, and the lithium-ion battery is obtained through the processes of vacuum packaging, standing, forming, shaping, and capacity testing.
- the lithium-ion battery that has reached a constant temperature is charged with a constant current of 0.7C to a voltage of 4.4V, and then charged with a constant voltage of 4.4V to a current of 0.025C. After standing for 5 minutes, it is discharged with a constant current of 0.5C to a voltage of 3.0V.
- the capacity obtained in this step is the initial capacity, and 0.7C charge/0.5C discharge is carried out for cycle test, and the capacity decay curve is obtained by taking the ratio of the capacity in each step to the initial capacity.
- the room temperature cycle performance of the battery was recorded as the number of cycles from 25°C to 90% of the capacity retention rate, and the number of cycles from 45°C to 80% of the capacity retention rate was recorded as the high-temperature cycle performance of the battery.
- the number of cycles in each case compares the cycle performance of the materials.
- Example 3 when the thickness of the silicon-containing material layer is increased to 10 nm, the cycle performance, expansion ratio and rate performance will be deteriorated; Comparative Example 1 directly shows that when the high silicon content reaches 75.9%, silicon Particle expansion can easily lead to the destruction of the anode material structure, which in turn leads to a serious degradation of its cycle performance.
- the mass percentage content of silicon in the negative electrode material is 32.4% to 52.5%.
- Example 6 From the test results of Examples 2, 6 and 7, it can be seen that under the premise that the silicon content of the negative electrode material, the thickness D 0 of the silicon-containing material layer, the pore diameter D 1 of the nitrogen-doped porous carbon and the nitrogen content are consistent, Example 6, The thickness D 2 of the carbon layer of 2 and 7 gradually increases. It can be seen that increasing the thickness of the carbon layer can effectively relieve the stress caused by the expansion of the internal silicon particles, maintain the stability of the structure during the charging and discharging process, and effectively isolate the electrolyte. , to avoid side reactions between the silicon particles and the electrolyte, and excessively increasing the thickness of the outer carbon layer increases the transmission distance of ions and electrons, which is not conducive to the rate performance and the high energy advantage of silicon.
- the ratio D 0 /D 1 of D 0 to the pore diameter D 1 of the nitrogen-doped porous carbon is both 0.7, other performance parameters are shown in Table 3-1, and the performance test results of the lithium battery prepared are shown in Table 3- 2 shown.
- the thickness of the outer carbon layer is increased, the powder conductivity of the negative electrode material is improved, and the thickness of the carbon-receiving layer is increased. Influenced by the influence of , the overall ID/ IG value of the negative electrode material decreases. After increasing the thickness of the carbon layer, the bonding to the inner core active material is better, the pore volume of the negative electrode material decreases, and the surface pore volume of the outer carbon layer decreases. It is beneficial to isolate the electrolyte and form a stable SEI film. The increase of the thickness of the carbon layer is beneficial to strengthen the restraint of the expansion stress of the silicon carbon core. Chemical properties, but the thickness of the carbon layer cannot be blindly increased, otherwise the silicon content of the negative electrode material will be reduced, and the energy density of the negative electrode material will be reduced.
- Example 22 directly shows that when the pore volume is increased by 15 cm 2 /g, the structure of the negative electrode material collapses after lithium intercalation, and the battery shows Rapid capacity decay and swelling increase.
- Example 25 directly shows that when the wall thickness increases to 40 nm, the buffering effect of the wall thickness on expansion is not enough to support the large increase in expansion stress, and the battery shows poor performance. electrochemical performance.
Abstract
The present application provides a negative electrode material and a preparation method therefor, an electrochemical device, and an electronic device. The negative electrode material comprises active materials and a carbon layer located on the surfaces of the active materials, and the active materials comprise nitrogen-doped porous carbon and a silicon-containing material layer; the mass percentage content of silicon in the negative electrode material is 30% to 80%; the thickness D0 of the silicon-containing material layer ranges from 1 nm to 10 nm; and the range of the ratio of the thickness D0 of the silicon-containing material layer to the pore size D1 of the nitrogen-doped porous carbon satisfies: 0.2≤D0/D1<0.8, and the range of the ratio of the thickness D0 of the silicon-containing material layer to the thickness D2 of the carbon layer satisfies: 0.05≤D0/D2≤10. According to the negative electrode material provided by the present application, the expansion of a negative electrode due to the expansion of silicon base and graphite can be effectively alleviated, thereby improving the cycle performance of the negative electrode.
Description
本申请涉及负极材料技术领域，具体地讲，涉及负极材料及其制备方法、电化学装置及电子装置。The present application relates to the technical field of anode materials, and in particular, to anode materials and preparation methods thereof, electrochemical devices and electronic devices.
目前，硅基负极材料具有高达1500～4200mAh/g的克容量，被认为是最具有应用前景的下一代锂离子负极材料。但是硅的低电导性(>10
8Ω.cm)，以及其在充放电过程中具有约300％的体积膨胀并生成不稳定的固体电解质界面膜(SEI)，硅负极材料在充放电过程中会粉化从集流体上掉落，使得活性物质与集流体之间失掉电接触，导致电化学性能变差，容量衰减、循环稳定性下降，一定程度上阻碍了其进一步的应用。将硅基负极材料进行纳米化并分散在碳基体中可以有效改善硅基负极材料的循环性能，例如可以通过将硅采用湿法研磨的方式球磨至100nm左右，进而与沥青，聚合物等进行造粒后碳化，从而得到现在主要应用的硅碳复合材料。但是，这种负极材料的循环性能较低，膨胀率也相对较大。
At present, silicon-based anode materials have a gram capacity as high as 1500-4200 mAh/g, and are considered to be the most promising next-generation lithium-ion anode materials. However, due to the low electrical conductivity of silicon (>10 8 Ω.cm), and its volume expansion of about 300% during charge-discharge and the formation of an unstable solid electrolyte interface (SEI), the silicon anode material in the charge-discharge process It will be pulverized and dropped from the current collector, causing the loss of electrical contact between the active material and the current collector, resulting in poor electrochemical performance, capacity decay, and cycle stability, which hinders its further application to a certain extent. Nano-sized silicon-based anode materials and dispersed in carbon matrix can effectively improve the cycle performance of silicon-based anode materials. After granulation, carbonization is carried out to obtain the silicon-carbon composite material that is mainly used now. However, the cycle performance of this anode material is low and the expansion rate is relatively large.
申请内容Application content
鉴于此，本申请提出了负极材料及其制备方法、电化学装置及电子装置，该负极材料可以有效缓解由于硅基与石墨膨胀导致负极的膨胀，从而改善负极材料的循环性能。In view of this, the present application proposes a negative electrode material and a preparation method thereof, an electrochemical device and an electronic device. The negative electrode material can effectively alleviate the expansion of the negative electrode due to the expansion of the silicon base and graphite, thereby improving the cycle performance of the negative electrode material.
第一方面，本申请提供一种负极材料，所述负极材料包括活性材料及位于所述活性材料表面的碳层，所述活性材料包括氮掺杂多孔碳及含硅材料层；所述负极材料中的硅的质量百分比含量为30％至80％。In a first aspect, the present application provides a negative electrode material, the negative electrode material includes an active material and a carbon layer on the surface of the active material, the active material includes nitrogen-doped porous carbon and a silicon-containing material layer; the negative electrode material The content of silicon in mass percentage is 30% to 80%.
结合第一方面，在一种可行的实施方式中，所述含硅材料层位于所述氮掺杂多孔碳的孔壁。In combination with the first aspect, in a feasible embodiment, the silicon-containing material layer is located on the pore walls of the nitrogen-doped porous carbon.
结合第一方面，在一种可行的实施方式中，所述负极材料满足以下条件(1)至(4)中的至少一者：In combination with the first aspect, in a feasible embodiment, the negative electrode material satisfies at least one of the following conditions (1) to (4):
(1)所述含硅材料层的厚度D
0的取值范围为1nm至10nm；
(1) The thickness D 0 of the silicon-containing material layer ranges from 1 nm to 10 nm;
(2)所述含硅材料层的厚度D
0与所述氮掺杂多孔碳的孔径D
1的比值范围满足：0.2≤D
0/D
1<0.8；
(2) The ratio range of the thickness D 0 of the silicon-containing material layer to the pore diameter D 1 of the nitrogen-doped porous carbon satisfies: 0.2≦D 0 /D 1 <0.8;
(3)所述含硅材料层的厚度D
0与所述碳层的厚度D
2的比值范围满足：0.05≤D
0/D
2≤10；
(3) The ratio range of the thickness D 0 of the silicon-containing material layer to the thickness D 2 of the carbon layer satisfies: 0.05≦D 0 /D 2 ≦10;
(4)所述氮掺杂多孔碳中的多孔碳的壁厚为5nm至30nm。(4) The porous carbon in the nitrogen-doped porous carbon has a wall thickness of 5 nm to 30 nm.
结合第一方面，在一种可行的实施方式中，所述氮掺杂多孔碳满足以下条件(1)至(3)中的至少一者：In combination with the first aspect, in a feasible embodiment, the nitrogen-doped porous carbon satisfies at least one of the following conditions (1) to (3):
(1)所述氮掺杂多孔碳的比表面积为2000m
2/g至3500m
2/g；
(1) the nitrogen-doped porous carbon has a specific surface area of 2000 m 2 /g to 3500 m 2 /g;
(2)所述氮掺杂多孔碳的孔体积为1cm
2/g至10cm
2/g；
(2) the nitrogen-doped porous carbon has a pore volume of 1 cm 2 /g to 10 cm 2 /g;
(3)所述氮掺杂多孔碳中的孔的平均孔径为1nm至20nm。(3) The average pore diameter of the pores in the nitrogen-doped porous carbon is 1 nm to 20 nm.
结合第一方面，在一种可行的实施方式中，所述负极材料满足以下条件(1)至(7)中的至少一者：In combination with the first aspect, in a feasible embodiment, the negative electrode material satisfies at least one of the following conditions (1) to (7):
(1)所述负极材料的比表面积为1m
2/g至50m
2/g；
(1) The specific surface area of the negative electrode material is 1 m 2 /g to 50 m 2 /g;
(2)所述负极材料的孔体积为0.001cm
2/g至0.1cm
2/g；
(2) the pore volume of the negative electrode material is 0.001 cm 2 /g to 0.1 cm 2 /g;
(3)所述负极材料的粒径范围为1um至100um，和/或，所述负极材料的平均粒径为2.5um至50um；(3) The particle size of the negative electrode material ranges from 1um to 100um, and/or the average particle size of the negative electrode material is 2.5um to 50um;
(4)所述负极材料的粉末电导率为2.0S/cm至30S/cm；(4) The powder conductivity of the negative electrode material is 2.0S/cm to 30S/cm;
(5)所述负极材料的碳层的厚度为2nm至20nm；(5) the thickness of the carbon layer of the negative electrode material is 2 nm to 20 nm;
(6)所述负极材料中的碳层的质量百分比含量为3％至10％；(6) The mass percentage content of the carbon layer in the negative electrode material is 3% to 10%;
(7)所述负极材料中的氮掺杂多孔碳的质量百分比含量为10％至67％。(7) The mass percentage content of nitrogen-doped porous carbon in the negative electrode material is 10% to 67%.
结合第一方面，在一种可行的实施方式中，通过拉曼光谱法，所述负极材料在1350cm
-1处的峰强度I
D与在1580cm
-1处的峰强度I
G的比值I
D/I
G的取值范围为1.2至2.2。
In combination with the first aspect, in a feasible embodiment, through Raman spectroscopy, the ratio of the peak intensity ID at 1350 cm −1 to the peak intensity I G at 1580 cm −1 of the negative electrode material ID / The value of IG ranges from 1.2 to 2.2.
结合第一方面，在一种可行的实施方式中，所述氮掺杂多孔碳满足以下条件(1)至(3)中的至少一者：In combination with the first aspect, in a feasible embodiment, the nitrogen-doped porous carbon satisfies at least one of the following conditions (1) to (3):
(1)所述氮掺杂多孔碳中的氮元素以C-N键形式掺杂在碳体相中；(1) The nitrogen element in the nitrogen-doped porous carbon is doped in the carbon bulk phase in the form of C-N bonds;
(2)所述氮掺杂多孔碳中的氮的质量百分比含量为0.5％至10％；(2) the mass percentage content of nitrogen in the nitrogen-doped porous carbon is 0.5% to 10%;
(3)通过XPS分析，所述氮掺杂多孔碳中的氮的构型包括吡啶类氮、吡咯类氮、石墨类氮、石墨化氮和氧化类氮中的至少一种，且所述石墨化氮在所有氮中的质量占比为30％至70％。(3) Through XPS analysis, the configuration of nitrogen in the nitrogen-doped porous carbon includes at least one of pyridine-based nitrogen, pyrrole-based nitrogen, graphitic nitrogen, graphitized nitrogen, and oxide-based nitrogen, and the graphite Nitrogen makes up 30% to 70% of all nitrogen by mass.
第二方面，本申请提供一种上述第一方面所述的负极材料的制备方法，所述方法包括以下步骤：In a second aspect, the present application provides a method for preparing the negative electrode material described in the first aspect, the method comprising the following steps:
将抗生素菌渣经金属盐高温碳化处理及酸洗处理，得到氮掺杂多孔碳；The antibiotic bacterial residue is subjected to high-temperature carbonization treatment and pickling treatment of metal salts to obtain nitrogen-doped porous carbon;
利用硅烷气体对所述氮掺杂多孔碳进行气相沉积，得到活性材料；Using silane gas to vapor-deposit the nitrogen-doped porous carbon to obtain an active material;
将所述活性材料与碳源混合后进行高温处理，得到负极材料。The active material is mixed with a carbon source and then subjected to high temperature treatment to obtain a negative electrode material.
结合第二方面，在一种可行的实施方式中，所述方法满足以下条件(1)至(3)中的至少一者：In conjunction with the second aspect, in a feasible implementation manner, the method satisfies at least one of the following conditions (1) to (3):
(1)所述碳源包括树脂、沥青、高分子聚合物中的至少一种；(1) The carbon source includes at least one of resin, pitch, and high molecular polymer;
(2)所述金属盐包括氯化钠、氯化钾、碳酸钠或碳酸钾中的至少一种；(2) described metal salt includes at least one in sodium chloride, potassium chloride, sodium carbonate or potassium carbonate;
(3)所述酸洗处理所采用的酸包括盐酸、硫酸、硝酸、草酸、氢氟酸或磷酸中的至少一种。(3) The acid used in the pickling treatment includes at least one of hydrochloric acid, sulfuric acid, nitric acid, oxalic acid, hydrofluoric acid or phosphoric acid.
第三方面，本申请提供一种负极极片，包括负极集流体以及设置于所述负极集流体表面的负极活性材料层，所述负极活性材料层包括上述第一方面所述的负极材料或上述第二方面所述的制备方法制得的负极材料。In a third aspect, the present application provides a negative electrode sheet, comprising a negative electrode current collector and a negative electrode active material layer disposed on the surface of the negative electrode current collector, the negative electrode active material layer comprising the negative electrode material described in the first aspect or the above The negative electrode material prepared by the preparation method described in the second aspect.
结合第三方面，在一种可行的实施方式中，所述负极极片满足以下条件(1)至(4)中的至少一者：In conjunction with the third aspect, in a feasible implementation manner, the negative pole piece satisfies at least one of the following conditions (1) to (4):
(1)所述负极活性材料层的孔隙率为20％至40％；(1) The porosity of the negative electrode active material layer is 20% to 40%;
(2)所述负极活性材料层的电阻的取值范围为0.2Ω至2Ω；(2) the value range of the resistance of the negative electrode active material layer is 0.2Ω to 2Ω;
(3)在5T压力下，所述负极活性材料层的压实密度为1.5g/cm
3至2.0g/cm
3；
(3) Under a pressure of 5T, the compaction density of the negative electrode active material layer is 1.5g/cm 3 to 2.0g/cm 3 ;
(4)所述负极活性材料层的OI值的取值范围为1至20。(4) The OI value of the negative electrode active material layer ranges from 1 to 20.
第四方面，本申请提供一种电化学装置，包括负极活性材料层，其特征在于，所述负极活性材料层包括上述第一方面所述的负极材料或上述第二方面所述的制备方法制得的负极材料。In a fourth aspect, the present application provides an electrochemical device comprising a negative electrode active material layer, characterized in that the negative electrode active material layer comprises the negative electrode material described in the first aspect or the preparation method described in the second aspect above. obtained negative electrode material.
结合第四方面，在一种可行的实施方式中，所述电化学装置为锂离子电池。With reference to the fourth aspect, in a feasible implementation manner, the electrochemical device is a lithium-ion battery.
第五方面，本申请提供一种电子装置，所述电子装置包括第四方面所述的电化学装置。In a fifth aspect, the present application provides an electronic device comprising the electrochemical device of the fourth aspect.
相对于现有技术，本申请至少具有以下有益效果：Compared with the prior art, the present application at least has the following beneficial effects:
本申请提供的负极材料，通过将硅材料沉积到氮掺杂多孔碳的孔壁上，利用氮掺杂多孔碳作为负极材料的支撑骨架，氮掺杂多孔碳的内部孔隙可以缓解一定的体积膨胀；并且通过控制含硅材料层厚度与氮掺杂多孔碳的孔径的比值，以及含硅材料层厚度与碳层的厚度的比值，避免含硅材料层膨胀破坏氮掺杂多孔碳的孔结构以及碳层；可以有效缓解由于硅材料与石墨膨胀导致负极的膨胀，从而改善负极活性材料的循环性能，降低电池的膨胀效率。In the negative electrode material provided by the present application, by depositing silicon material on the pore walls of nitrogen-doped porous carbon, and using nitrogen-doped porous carbon as the supporting framework of the negative electrode material, the internal pores of nitrogen-doped porous carbon can alleviate a certain volume expansion ; And by controlling the ratio of the thickness of the silicon-containing material layer to the pore size of the nitrogen-doped porous carbon, and the ratio of the thickness of the silicon-containing material layer to the thickness of the carbon layer, the expansion of the silicon-containing material layer can be prevented from damaging the pore structure of the nitrogen-doped porous carbon and Carbon layer; can effectively alleviate the expansion of the negative electrode caused by the expansion of silicon material and graphite, thereby improving the cycle performance of the negative electrode active material and reducing the expansion efficiency of the battery.
图1为本申请实施例提供的负极材料的结构示意图。FIG. 1 is a schematic structural diagram of a negative electrode material provided in an embodiment of the present application.
以下所述是本申请实施例的优选实施方式，应当指出，对于本技术领域的普通技术人员来说，在不脱离本申请实施例原理的前提下，还可以做出若干改进和润饰，这些改进和润饰也视为本申请实施例的保护范围。The following are preferred implementations of the embodiments of the present application. It should be pointed out that for those skilled in the art, without departing from the principles of the embodiments of the present application, several improvements and modifications can be made. These improvements and modification are also regarded as the protection scope of the embodiments of the present application.
为了简便，本文仅明确地公开了一些数值范围。然而，任意下限可以与任何上限组合形成未明确记载的范围；以及任意下限可以与其它下限组合形成未明确记载的范围，同样任意上限可以与任意其它上限组合形成未明确记载的范围。此外，尽管未明确记载，但是范围端点间的每个点或单个数值都包含在该范围内。因而，每个点或单个数值可以作为自身的下限或上限与任意其它点或单个数值组合或与其它下限或上限组合形成未明确记载的范围。For the sake of brevity, only some numerical ranges are expressly disclosed herein. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with any other lower limit to form an unspecified range, and likewise any upper limit can be combined with any other upper limit to form an unspecified range. Furthermore, every point or single value between the endpoints of a range is included within the range, even if not expressly recited. Thus, each point or single value may serve as its own lower or upper limit in combination with any other point or single value or with other lower or upper limits to form a range not expressly recited.
在本文的描述中，需要说明的是，除非另有说明，“以上”、“以下”为包含本数，“一种或多种”中“多种”的含义是两个以上。In the description herein, it should be noted that, unless otherwise specified, “above” and “below” are inclusive of the numbers, and the meaning of “multiple” in “one or more” means two or more.
本申请的上述申请内容并不意欲描述本申请中的每个公开的实施方式或每种实现方式。如下描述更具体地举例说明示例性实施方式。在整篇申请中的多处，通过一系列实施例提供了指导，这些实施例可以以各种组合形式使用。在各个实例中，列举仅作为代表性组，不应解释为穷举。The above summary of this application is not intended to describe each disclosed embodiment or every implementation in this application. The following description illustrates exemplary embodiments in more detail. In various places throughout this application, guidance is provided through a series of examples, which examples can be used in various combinations. In various instances, the enumeration is merely a representative group and should not be construed as exhaustive.
第一方面，本申请实施例提供了一种负极材料，如图1所示，所述负极材料包括活性材料10及位于所述活性材料表面的碳层20，所述活性材料10包括氮掺杂多孔碳及含硅材料层11；所述负极材料中的硅的质量百分比含量为30％至80％。In the first aspect, an embodiment of the present application provides a negative electrode material. As shown in FIG. 1 , the negative electrode material includes an active material 10 and a carbon layer 20 on the surface of the active material, and the active material 10 includes nitrogen doping Porous carbon and silicon-containing material layer 11; the mass percentage content of silicon in the negative electrode material is 30% to 80%.
本申请提供的负极材料，通过将硅材料沉积到氮掺杂多孔碳的孔壁上，利用氮掺杂多孔碳作为负极材料的支撑骨架，氮掺杂多孔碳的内部孔隙12可以缓解一定的体积膨胀，可以有效缓解由于硅材料与石墨膨胀导致负极的膨胀，从而改善负极活性材料的循环性能。In the negative electrode material provided by the present application, by depositing silicon material on the pore walls of nitrogen-doped porous carbon, and using nitrogen-doped porous carbon as the supporting framework of the negative electrode material, the internal pores 12 of nitrogen-doped porous carbon can relieve a certain volume The expansion can effectively alleviate the expansion of the negative electrode caused by the expansion of the silicon material and the graphite, thereby improving the cycle performance of the negative electrode active material.
在本实施例中，所述含硅材料层位于所述氮掺杂多孔碳的孔壁。并且采用氮掺杂多孔碳作为负极材料的骨架结构，使得负极材料能够为锂离子附着提供更多的活性点位，进而使得锂离子电池具有更好的充放电循环性能。In this embodiment, the silicon-containing material layer is located on the pore walls of the nitrogen-doped porous carbon. And nitrogen-doped porous carbon is used as the skeleton structure of the negative electrode material, so that the negative electrode material can provide more active sites for the attachment of lithium ions, thereby making the lithium ion battery have better charge-discharge cycle performance.
其中，所述负极材料中的硅的质量百分比含量为30％至80％，具体可以是30％、32.4％、44.3％、52.5％、60％、65％、70％或80％等等，当然也可以是上述范围内的其他值，在此不做限定。可以理解地，当负极材料中的硅含量过高时，会显著提高负极材料的膨胀率，容易引起负极材料结构的破坏，导致电池的循环性能下降；当负极材料中的硅含量过低时，会降低负极材料的克容量，影响负极材料的能力密度。优选地，所述负极材料中的硅的质量百分比含量为32.4％至52.5％。Wherein, the mass percentage content of silicon in the negative electrode material is 30% to 80%, specifically 30%, 32.4%, 44.3%, 52.5%, 60%, 65%, 70% or 80%, etc. Of course, Other values within the above range are also possible, which are not limited here. It is understandable that when the silicon content in the negative electrode material is too high, the expansion rate of the negative electrode material will be significantly increased, which will easily lead to the destruction of the negative electrode material structure, resulting in a decrease in the cycle performance of the battery; when the silicon content in the negative electrode material is too low, It will reduce the gram capacity of the negative electrode material and affect the capacity density of the negative electrode material. Preferably, the mass percentage content of silicon in the negative electrode material is 32.4% to 52.5%.
所述含硅材料层的厚度D
0的取值范围为1nm至10nm，具体可以是1nm、2nm、3nm、4nm、5nm、6nm、7nm、8nm、9nm或10nm等等，当然也可以是上述范围内的其他值，在此不做限定。含硅材料层的厚度过小，材料的电化学性能下降，电池容量下降；含硅材料层的厚度过大，硅的体积膨胀效应更明显，容易破坏氮掺杂多孔碳的孔结构以及碳层，使得电池循环性能下降。优选地，所述含硅材料层的厚度D
0的取值范围为5nm至10nm。
The thickness D 0 of the silicon-containing material layer ranges from 1 nm to 10 nm, specifically 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, or 10 nm, etc., of course, it can also be the above range Other values within are not limited here. If the thickness of the silicon-containing material layer is too small, the electrochemical performance of the material will decrease, and the battery capacity will decrease; if the thickness of the silicon-containing material layer is too large, the volume expansion effect of silicon will be more obvious, which will easily destroy the pore structure of nitrogen-doped porous carbon and the carbon layer. , which degrades the battery cycle performance. Preferably, the thickness D 0 of the silicon-containing material layer ranges from 5 nm to 10 nm.
作为本申请可选的技术方案，所述氮掺杂多孔碳中的孔的平均孔径D
1为1nm至20nm，具体可以是1nm、2nm、3nm、5nm、8nm、10nm、12nm、15nm、18nm或20nm等等，但并不仅限于所列举的数值，该数值范围内其他未列举的数值同样适用。优选地，所述氮掺杂多孔碳中的孔的平均孔径D
1为12nm至20nm。
As an optional technical solution of the present application, the average pore diameter D 1 of the pores in the nitrogen-doped porous carbon is 1 nm to 20 nm, specifically 1 nm, 2 nm, 3 nm, 5 nm, 8 nm, 10 nm, 12 nm, 15 nm, 18 nm or 20nm, etc., but are not limited to the recited values, and other unrecited values within the numerical range are also applicable. Preferably, the average pore diameter D 1 of the pores in the nitrogen-doped porous carbon is 12 nm to 20 nm.
所述含硅材料层的厚度D
0与所述氮掺杂多孔碳的孔径D
1的比值范围满足：0.2≤D
0/D
1<0.8，具体可以是0.2、0.25、0.3、0.35、0.4、0.45、0.5、0.55、0.6、0.65或0.7等等，当然也可以是上述范围内的其他值，在此不做限定。
The ratio range of the thickness D 0 of the silicon-containing material layer to the pore diameter D 1 of the nitrogen-doped porous carbon satisfies: 0.2≤D 0 /D 1 <0.8, specifically 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, or 0.7, etc., of course, other values within the above range are also possible, which are not limited here.
作为本申请可选的技术方案，所述负极材料的碳层的厚度D
2为2nm至20nm，具体可以是2nm、3nm、4nm、5nm、7nm、8nm、10nm、12nm、15nm、18nm或20nm等，当然也可以是上述范围内的其他值，在此不做限定。可以理解地，碳层过厚，锂离子传输效率降低，不利于材料大倍率充放电，降低负极材料的综合性能；碳层过薄，不利于增加负极材料的导电性且对材料的体积膨胀抑制性能较弱，导致长循环性能较差。
As an optional technical solution of the present application, the thickness D 2 of the carbon layer of the negative electrode material is 2 nm to 20 nm, specifically 2 nm, 3 nm, 4 nm, 5 nm, 7 nm, 8 nm, 10 nm, 12 nm, 15 nm, 18 nm or 20 nm, etc. , and of course other values within the above range, which are not limited here. It is understandable that if the carbon layer is too thick, the lithium ion transmission efficiency is reduced, which is not conducive to the high-rate charge and discharge of the material, and reduces the comprehensive performance of the negative electrode material; if the carbon layer is too thin, it is not conducive to increasing the conductivity of the negative electrode material and suppresses the volume expansion of the material. Weak performance, resulting in poor performance for long loops.
所述含硅材料层的厚度D
0与所述碳层的厚度D
2的比值范围满足：0.05≤D
0/D
2≤10，具体可以是0.05、0.1、0.5、1、2、3、4、5、6、7、8、9或10等等，当然也可以是上述范围内的其他值，在此不做限定。
The ratio range of the thickness D 0 of the silicon-containing material layer to the thickness D 2 of the carbon layer satisfies: 0.05≦D 0 /D 2 ≦10, specifically 0.05, 0.1, 0.5, 1, 2, 3, 4 , 5, 6, 7, 8, 9, or 10, etc., of course, other values within the above range may also be used, which are not limited herein.
可以理解地，通过控制含硅材料层厚度与氮掺杂多孔碳的孔径的比值，以及含硅材料层厚度与碳层的厚度的比值，避免含硅材料层膨胀破坏氮掺杂多孔碳的孔结构以及碳层，从而提高电池的循环能力，降低电池的膨胀效率。Understandably, by controlling the ratio of the thickness of the silicon-containing material layer to the pore size of the nitrogen-doped porous carbon, and the ratio of the thickness of the silicon-containing material layer to the thickness of the carbon layer, the expansion of the silicon-containing material layer can be prevented from damaging the pores of the nitrogen-doped porous carbon. structure and carbon layer, thereby improving the cycle ability of the battery and reducing the expansion efficiency of the battery.
作为本申请可选的技术方案，所述氮掺杂多孔碳的比表面积为2000m
2/g至 3500m
2/g；具体可以是2000m
2/g、2200m
2/g、2500m
2/g、2800m
2/g、3000m
2/g或3500m
2/g等等，但并不仅限于所列举的数值，该数值范围内其他未列举的数值同样适用。
As an optional technical solution of the present application, the specific surface area of the nitrogen-doped porous carbon is 2000m 2 /g to 3500m 2 /g; specifically, it can be 2000m 2 /g, 2200m 2 /g, 2500m 2 /g, 2800m 2 /g, 3000m 2 /g or 3500m 2 /g, etc., but are not limited to the recited values, and other unrecited values within the range of values are also applicable.
所述氮掺杂多孔碳的孔体积为1cm
2/g至10cm
2/g；具体可以是1cm
2/g、2cm
2/g、3cm
2/g、4cm
2/g、5cm
2/g、6cm
2/g、8cm
2/g、9cm
2/g或10cm
2/g等等，但并不仅限于所列举的数值，该数值范围内其他未列举的数值同样适用。
The pore volume of the nitrogen-doped porous carbon is 1 cm 2 /g to 10 cm 2 /g; specifically, it may be 1 cm 2 /g, 2 cm 2 /g, 3 cm 2 /g, 4 cm 2 /g, 5 cm 2 /g, 6 cm 2 /g, 8cm 2 /g, 9cm 2 /g or 10cm 2 /g, etc., but are not limited to the recited values, and other unrecited values within the range of values are also applicable.
可以理解地，氮掺杂多孔碳具有较大的比表面积与孔体积，可以有利于含硅材料层沉积于氮掺杂多孔碳的孔结构内，并且氮掺杂多孔碳内部孔隙可以缓解一定的体积膨胀。It is understandable that nitrogen-doped porous carbon has a large specific surface area and pore volume, which can facilitate the deposition of silicon-containing material layers in the pore structure of nitrogen-doped porous carbon, and the internal pores of nitrogen-doped porous carbon can alleviate certain problems. volume expansion.
作为本申请可选的技术方案，所述氮掺杂多孔碳中的多孔碳的壁厚为5nm至30nm；具体可以是5nm、8nm、10nm、15nm、18nm、20nm、22nm、25nm、28nm、或30nm等，当然也可以是上述范围内的其他值，在此不做限定。可以理解地，将氮掺杂多孔碳中的多孔碳的壁厚控制在上述范围内，能够有效提高氮掺杂多孔碳作为负极材料的骨架结构的刚性，有利于提高材料的循环性能。As an optional technical solution of the present application, the wall thickness of the porous carbon in the nitrogen-doped porous carbon is 5 nm to 30 nm; Of course, other values within the above range are also possible, such as 30 nm, and are not limited here. Understandably, controlling the wall thickness of the porous carbon in the nitrogen-doped porous carbon within the above range can effectively improve the rigidity of the skeleton structure of the nitrogen-doped porous carbon as a negative electrode material, which is beneficial to improve the cycle performance of the material.
作为本申请可选的技术方案，所述氮掺杂多孔碳中的氮元素以C-N键形式掺杂在碳体相中。具体地，所述氮掺杂多孔碳中的氮的质量百分比含量为0.5％至10％，具体可以是0.5％、0.8％、1％、2％、3％、5％、7％、9％或10％等等，当然也可以是上述范围内的其他值，在此不做限定。As an optional technical solution of the present application, the nitrogen element in the nitrogen-doped porous carbon is doped in the carbon bulk phase in the form of C-N bonds. Specifically, the mass percentage content of nitrogen in the nitrogen-doped porous carbon is 0.5% to 10%, specifically 0.5%, 0.8%, 1%, 2%, 3%, 5%, 7%, 9% Or 10%, etc., of course, other values within the above range are also possible, which are not limited here.
作为本申请可选的技术方案，通过XPS分析，所述氮掺杂多孔碳中的氮的构型包括吡啶类氮、吡咯类氮、石墨类氮、石墨化氮和氧化类氮中的至少一种，且所述石墨化氮在所有氮中的质量占比为30％至70％，具体可以是30％、40％、50％、60％或70％等等。As an optional technical solution of the present application, through XPS analysis, the configuration of nitrogen in the nitrogen-doped porous carbon includes at least one of pyridine nitrogen, pyrrole nitrogen, graphitic nitrogen, graphitized nitrogen and oxide nitrogen and the mass proportion of the graphitized nitrogen in all nitrogen is 30% to 70%, specifically 30%, 40%, 50%, 60% or 70%, etc.
作为本申请可选的技术方案，所述负极材料中的氮掺杂多孔碳的质量百分比含量为10％至67％，具体可以是10％、20％、25％、30％、35％、40％、50％或67％等等，当然也可以是上述范围内的其他值，在此不做限定。As an optional technical solution of the present application, the mass percentage content of nitrogen-doped porous carbon in the negative electrode material is 10% to 67%, specifically 10%, 20%, 25%, 30%, 35%, 40% %, 50% or 67%, etc., of course, other values within the above range can also be used, which are not limited here.
作为本申请可选的技术方案，所述负极材料中的碳层的质量百分比含量为3％至10％，具体可以是3％、4％、5％、6％、7％、8％、9％或10％等等，当然也可以是上述范围内的其他值，在此不做限定。As an optional technical solution of the present application, the mass percentage content of the carbon layer in the negative electrode material is 3% to 10%, specifically 3%, 4%, 5%, 6%, 7%, 8%, 9% % or 10%, etc., of course, other values within the above range are also possible, which are not limited here.
作为本申请可选的技术方案，所述负极材料的比表面积为1m
2/g至50m
2/g，具体可以是1m
2/g、5m
2/g、10m
2/g、15m
2/g、20m
2/g、25m
2/g、30m
2/g、40m
2/g、49m
2/g或50m
2/g等等，但并不仅限于所列举的数值，该数值范围内其他未列举的数值同样适用。所述负极材料的比表面积在上述范围内，保证了材料的加工性能，有利于提高由该负极材料制成的锂电池的首次效率，有利于提高负极材料的循环性能。优选地，所述负极材料的比表面积为2.1m
2/g至5.2m
2/g。
As an optional technical solution of the present application, the specific surface area of the negative electrode material is 1 m 2 /g to 50 m 2 /g, specifically 1 m 2 /g, 5 m 2 /g, 10 m 2 /g, 15 m 2 /g, 20m 2 /g, 25m 2 /g, 30m 2 /g, 40m 2 /g, 49m 2 /g or 50m 2 /g, etc., but not limited to the recited values, other unrecited values within the range of values The same applies. The specific surface area of the negative electrode material is within the above range, which ensures the processing performance of the material, is conducive to improving the primary efficiency of the lithium battery made of the negative electrode material, and is conducive to improving the cycle performance of the negative electrode material. Preferably, the specific surface area of the negative electrode material is 2.1 m 2 /g to 5.2 m 2 /g.
作为本申请可选的技术方案，所述负极材料的孔体积为0.001cm
2/g至0.1cm
2/g；具体可以是0.001cm
2/g、0.005cm
2/g、0.01cm
2/g、0.03cm
2/g、0.05cm
2/g、0.06cm
2/g、0.08cm
2/g、0.09cm
2/g或0.1cm
2/g等等，但并不仅限于所列举的数值，该数值范围内其他未列举的数值同样适用。可以理解地，负极材料较小的孔体积表明外层碳层表面的孔结构较少，对内核的活性材料结合较好，有利于隔绝内核活性材料与电解液的接触，形成稳定的SEI膜，提供稳定的循环性能。
As an optional technical solution of the present application, the pore volume of the negative electrode material is 0.001 cm 2 / g to 0.1 cm 2 / g ; 0.03cm 2 /g, 0.05cm 2 /g, 0.06cm 2 /g, 0.08cm 2 /g, 0.09cm 2 / g or 0.1cm 2 /g, etc., but not limited to the enumerated numerical values, the numerical range The same applies to other values not listed here. It is understandable that the smaller pore volume of the negative electrode material indicates that the surface of the outer carbon layer has less pore structure, and the active material of the inner core is well combined, which is beneficial to isolate the contact between the active material of the inner core and the electrolyte, and form a stable SEI film. Provides stable cycle performance.
作为本申请可选的技术方案，所述负极材料的粒径范围为1um至100um，具体可以是1um、5um、10um、15um、20um、30um、40um、50um、60um、70um、80um、90um或100um等等，但并不仅限于所列举的数值，该数值范围内其他未列举的数值同样适用。可选地，所述负极材料的平均粒径D
50为2.5um至50um。
As an optional technical solution of the present application, the particle size of the negative electrode material ranges from 1um to 100um, specifically 1um, 5um, 10um, 15um, 20um, 30um, 40um, 50um, 60um, 70um, 80um, 90um or 100um etc., but are not limited to the recited values, other non-recited values within the range of values also apply. Optionally, the average particle size D50 of the negative electrode material is 2.5um to 50um.
作为本申请可选的技术方案，所述负极材料的粉末电导率为2.0S/cm至30S/cm，具体可以是2.0S/cm、2.5S/cm、3.0S/cm、5.0S/cm、8.0S/cm、10S/cm、15S/cm、20S/cm、25S/cm或30S/cm等等，但并不仅限于所列举的数值，该数值范围内其他未列举的数值同样适用。As an optional technical solution of the present application, the powder conductivity of the negative electrode material is 2.0S/cm to 30S/cm, specifically 2.0S/cm, 2.5S/cm, 3.0S/cm, 5.0S/cm, 8.0S/cm, 10S/cm, 15S/cm, 20S/cm, 25S/cm or 30S/cm, etc., but not limited to the recited values, and other unrecited values within the range of values are also applicable.
作为本申请可选的技术方案，通过拉曼光谱法，所述负极材料在1350cm
-1处的峰强度I
D与在1580cm
-1处的峰强度I
G的比值I
D/I
G的取值范围为1.2至2.2；I
D/I
G的取值具体可以是1.2、1.4、1.5、1.8、1.9、2.0或2.2等等，但并不仅限于所列举的数值，该数值范围内其他未列举的数值同样适用。当比值过高，表示负极材料的表面缺陷度高，会增加固体电解质(SEI)膜的形成，消耗更多的锂离子，使得电池首次效率下降。当比值过低，负极材料的动力学性能下降。
As an optional technical solution of the present application, through Raman spectroscopy , the value of the ratio ID / IG of the peak intensity ID at 1350 cm −1 to the peak intensity IG at 1580 cm −1 of the negative electrode material The range is 1.2 to 2.2 ; the value of ID / IG can be specifically 1.2, 1.4, 1.5, 1.8, 1.9, 2.0 or 2.2, etc., but is not limited to the listed values, and other unlisted values within the range of values The same applies to numerical values. When the ratio is too high, it means that the surface defect of the negative electrode material is high, which will increase the formation of solid electrolyte (SEI) film, consume more lithium ions, and reduce the first efficiency of the battery. When the ratio is too low, the kinetic performance of the anode material decreases.
第二方面，本申请提供一种负极材料的制备方法，所述方法包括以下步骤：In a second aspect, the present application provides a method for preparing a negative electrode material, the method comprising the following steps:
步骤S10，将抗生素菌渣经金属盐高温碳化处理及酸洗处理得到氮掺杂多孔碳；In step S10, nitrogen-doped porous carbon is obtained by subjecting the antibiotic bacterial residue to high-temperature carbonization treatment and pickling treatment of metal salts;
步骤S20，利用硅烷气体对所述氮掺杂多孔碳进行气相沉积，得到活性材料；Step S20, using silane gas to vapor-deposit the nitrogen-doped porous carbon to obtain an active material;
步骤S30，将所述活性材料与碳源混合后进行高温处理，得到负极材料。In step S30, the active material is mixed with the carbon source and then subjected to high temperature treatment to obtain a negative electrode material.
在上述方案中，采用硅源气体热分解的方式将硅沉积到氮掺杂多孔碳中，可以有效缓解由于硅基与石墨膨胀导致负极的膨胀，可以有效改善负极活性材料的循环性能。In the above scheme, the thermal decomposition of silicon source gas is used to deposit silicon into nitrogen-doped porous carbon, which can effectively alleviate the expansion of the negative electrode due to the expansion of the silicon base and graphite, and can effectively improve the cycle performance of the negative electrode active material.
以下结合实施例具体介绍本制备方法：Below in conjunction with embodiment, this preparation method is specifically introduced:
步骤S10，将抗生素菌渣经金属盐高温碳化处理及酸洗处理得到氮掺杂多孔碳。In step S10, nitrogen-doped porous carbon is obtained by subjecting the antibiotic bacterial residue to high-temperature carbonization treatment and pickling treatment of metal salts.
作为本申请可选的技术方案，所述抗生素菌渣与金属盐的质量比为(0.1～2):1，具体可以是0.1:1、0.3:1、0.5:1、0.8:1、1:1、1.2:1、1.5:1、1.8:1或2:1等，当然也可以是上述范围内的其他值。As an optional technical solution of the present application, the mass ratio of the antibiotic slag to the metal salt is (0.1～2):1, specifically 0.1:1, 0.3:1, 0.5:1, 0.8:1, 1:1 1, 1.2:1, 1.5:1, 1.8:1 or 2:1, etc. Of course, other values within the above range are also possible.
在进行高温碳化处理之前，将抗生素菌渣与金属盐投入到去离子水中，搅拌均匀后置于110℃烘箱干燥。Before the high-temperature carbonization treatment, the antibiotic slag and metal salt were put into deionized water, stirred evenly, and then placed in an oven at 110°C for drying.
作为本身可选的技术方案，所述金属盐包括氯化钠、氯化钾、碳酸钠或碳酸钾中的至少一种。As an optional technical solution, the metal salt includes at least one of sodium chloride, potassium chloride, sodium carbonate or potassium carbonate.
作为本身可选的技术方案，所述高温碳化处理的温度为600℃至1000℃，具体可以是600℃、700℃、800℃、900℃、950℃或1000℃等，当然也可以是上述范围内的其他值。控制升温速率为1℃/min至10℃/min，具体可以是1℃/min、2℃/min、3℃/min、4℃/min、5℃/min、6℃/min、7℃/min、8℃/min或10℃/min等，当然也可以是上述范围内的其他值。As an optional technical solution, the temperature of the high-temperature carbonization treatment is 600°C to 1000°C, specifically 600°C, 700°C, 800°C, 900°C, 950°C or 1000°C, etc., of course, it can also be the above range other values within. Control the heating rate from 1°C/min to 10°C/min, specifically 1°C/min, 2°C/min, 3°C/min, 4°C/min, 5°C/min, 6°C/min, 7°C/min min, 8° C./min, or 10° C./min, etc., of course, other values within the above-mentioned range are also possible.
所述高温碳化处理的保温时间为1h至3h，具体可以是1h、1.5h、2h、2.5h或3h等，当然也可以是上述范围内的其他值。The holding time of the high-temperature carbonization treatment is 1h to 3h, specifically 1h, 1.5h, 2h, 2.5h or 3h, etc., of course, other values within the above range are also possible.
可以理解地，通过高温碳化处理，可以得到含金属元素的氮掺杂碳材料。It is understandable that a nitrogen-doped carbon material containing metal elements can be obtained by high-temperature carbonization.
进一步地，将氮掺杂碳材料中的金属元素经过酸洗处理，使得金属元素溶于酸溶液中，进而使得氮掺杂碳材料形成多孔结构。Further, the metal element in the nitrogen-doped carbon material is subjected to acid washing treatment, so that the metal element is dissolved in the acid solution, so that the nitrogen-doped carbon material forms a porous structure.
可选地，所述酸洗处理所采用的酸包括盐酸、硫酸、硝酸、草酸、氢氟酸或磷酸中的至少一种。Optionally, the acid used in the pickling treatment includes at least one of hydrochloric acid, sulfuric acid, nitric acid, oxalic acid, hydrofluoric acid or phosphoric acid.
步骤S20，利用硅烷气体对所述氮掺杂多孔碳进行气相沉积，得到活性材料。Step S20 , vapor-depositing the nitrogen-doped porous carbon with silane gas to obtain an active material.
作为本申请可选的技术方案，所述气相沉积的温度为400℃至600℃，具体可以是400℃、450℃、500℃、550℃或600℃等，当然也可以是上述范围内的其他值。As an optional technical solution of the present application, the temperature of the vapor deposition is 400°C to 600°C, specifically 400°C, 450°C, 500°C, 550°C, or 600°C, etc., of course, other temperatures within the above range are also possible. value.
作为本申请可选的技术方案，所述气相沉积的沉积时间为0.5h至3h，具体可以是0.5h、1h、1.5h、2h、2.5h或3h等，当然也可以是上述范围内的其他值。As an optional technical solution of the present application, the deposition time of the vapor deposition is 0.5h to 3h, specifically 0.5h, 1h, 1.5h, 2h, 2.5h or 3h, etc. Of course, it can also be other within the above range value.
在本实施例中，硅烷气体在惰性气体保护下对氮掺杂多孔碳进行气相沉积。具体地，硅烷气体的惰性气体中的体积占比为2％至6％，具体可以是2％、3％、4％、5％或6％等，当然也可以是上述范围内的其他值。In this embodiment, nitrogen-doped porous carbon is vapor-deposited with silane gas under the protection of inert gas. Specifically, the volume ratio of the silane gas in the inert gas is 2% to 6%, specifically 2%, 3%, 4%, 5%, or 6%, etc., of course, other values within the above-mentioned range are also possible.
步骤S30，将所述活性材料与碳源混合后进行碳复合处理，得到负极材料。In step S30, the active material is mixed with a carbon source and then carbon composite treatment is performed to obtain a negative electrode material.
作为本申请可选的技术方案，所述碳源包括树脂、沥青、高分子聚合物中的至少一种。As an optional technical solution of the present application, the carbon source includes at least one of resin, pitch, and high molecular polymer.
在进行碳复合处理之前，可以将活性材料与碳源分散于液相体系(例如水)中，搅拌后使其充分混合均匀，再进行干燥，干燥后的混合物进行碳复合处理。Before carbon composite treatment, the active material and carbon source can be dispersed in a liquid phase system (for example, water), stirred and mixed well, and then dried, and the dried mixture is subjected to carbon composite treatment.
作为本申请可选的技术方案，所述碳复合处理的温度为500℃至1200℃，具体可以是500℃、550℃、600℃、700℃、800℃、900℃、1000℃、1100℃或1200℃等，当然也可以是上述范围内的其他值。控制升温速率为1℃/min至10℃/min，具体可以是1℃/min、2℃/min、3℃/min、4℃/min、5℃/min、6℃/min、7℃/min、8℃/min或10℃/min等，当然也可以是上述范围内的其他值。As an optional technical solution of the present application, the temperature of the carbon composite treatment is 500°C to 1200°C, specifically 500°C, 550°C, 600°C, 700°C, 800°C, 900°C, 1000°C, 1100°C or Of course, other values within the above-mentioned range are also possible, such as 1200°C. Control the heating rate from 1°C/min to 10°C/min, specifically 1°C/min, 2°C/min, 3°C/min, 4°C/min, 5°C/min, 6°C/min, 7°C/min min, 8° C./min, or 10° C./min, etc., of course, other values within the above-mentioned range are also possible.
作为本申请可选的技术方案，所述碳复合处理的时间为1h至24h；具体可以是1h、2h、6h、12h、18h或24h等，当然也可以是上述范围内的其他值。As an optional technical solution of the present application, the carbon composite treatment time is 1h to 24h; specifically, it can be 1h, 2h, 6h, 12h, 18h or 24h, etc., of course, it can also be other values within the above range.
作为本申请可选的技术方案，所述碳复合处理在惰性气体保护下进行，惰性气体例如可以是氮气、氩气、氦气、氪气等中的至少一种。As an optional technical solution of the present application, the carbon composite treatment is performed under the protection of an inert gas, and the inert gas can be, for example, at least one of nitrogen, argon, helium, krypton and the like.
第三方面，本申请实施例提供了一种负极极片，所述负极极片包括负极集流体和位于负极集流体上的负极活性材料层，所述负极活性材料层包括根据本申请第一方面的负极材料。In a third aspect, an embodiment of the present application provides a negative electrode sheet, the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer on the negative electrode current collector, the negative electrode active material layer comprises the negative electrode active material layer according to the first aspect of the present application negative electrode material.
作为本申请可选的技术方案，负极活性材料层包括粘合剂，粘合剂包括聚乙烯醇、羧甲基纤维素、羟丙基纤维素、二乙酰基纤维素、聚氯乙烯、羧化的聚氯乙烯、聚氟乙烯、含亚乙基氧的聚合物、聚乙烯吡咯烷酮、聚氨酯、聚四氟乙烯、聚偏1,1-二氟乙烯、聚乙烯、聚丙烯、丁苯橡胶、丙烯酸(酯)化的丁苯橡胶、环氧树脂或尼龙等，在此不做限定。As an optional technical solution of the present application, the negative electrode active material layer includes a binder, and the binder includes polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide-containing polymers, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylic The (esterified) styrene-butadiene rubber, epoxy resin, nylon, etc., are not limited here.
作为本申请可选的技术方案，负极活性材料层还包括导电材料，导电材料包括天然石墨、人造石墨、碳黑、乙炔黑、科琴黑、碳纤维、金属粉、金属纤维、铜、镍、铝、银或聚亚苯基衍生物等，在此不做限定。As an optional technical solution of the present application, the negative electrode active material layer further includes a conductive material, and the conductive material includes natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, metal powder, metal fiber, copper, nickel, aluminum , silver or polyphenylene derivatives, etc., are not limited here.
作为本申请可选的技术方案，负极集流体包括，但不限于：铜箔、镍箔、不锈钢 箔、钛箔、泡沫镍、泡沫铜或覆有导电金属的聚合物基底。As an optional technical solution of the present application, the negative electrode current collector includes, but is not limited to: copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, foamed copper or a polymer substrate coated with conductive metal.
作为本申请可选的技术方案，所述负极活性材料层的孔隙率为20％至40％，具体可以是20％、23％、25％、28％、30％、33％、35％、38％或40％等，当然也可以是上述范围内的其他值。As an optional technical solution of the present application, the porosity of the negative electrode active material layer is 20% to 40%, specifically 20%, 23%, 25%, 28%, 30%, 33%, 35%, 38% % or 40%, and of course other values within the above range are also possible.
作为本申请可选的技术方案，所述负极活性材料层的电阻的取值范围为0.2Ω至2Ω，具体可以是0.2Ω、0.5Ω、0.8Ω、1Ω、1.2Ω、1.5Ω、1.8Ω或2Ω等，当然也可以是上述范围内的其他值。As an optional technical solution of the present application, the value range of the resistance of the negative electrode active material layer is 0.2Ω to 2Ω, specifically 0.2Ω, 0.5Ω, 0.8Ω, 1Ω, 1.2Ω, 1.5Ω, 1.8Ω or 2Ω, etc., of course, other values within the above range are also possible.
作为本申请可选的技术方案，在5T压力下，所述负极活性材料层的压实密度为1.5g/cm
3至2.0g/cm
3，具体可以是1.5g/cm
3、1.6g/cm
3、1.7g/cm
3、1.8g/cm
3、1.9g/cm
3或2.0g/cm
3等，当然也可以是上述范围内的其他值。
As an optional technical solution of the present application, under a pressure of 5T, the compaction density of the negative electrode active material layer is 1.5g/cm 3 to 2.0g/cm 3 , specifically 1.5g/cm 3 , 1.6g/cm 3 3 , 1.7 g/cm 3 , 1.8 g/cm 3 , 1.9 g/cm 3 or 2.0 g/cm 3 , etc., of course, other values within the above range are also possible.
作为本申请可选的技术方案，所述负极活性材料层的OI值的取值范围为1至20，具体可以是1、3、5、8、10、13、15、18或20等，当然也可以是上述范围内的其他值。As an optional technical solution of the present application, the OI value of the negative electrode active material layer ranges from 1 to 20, specifically 1, 3, 5, 8, 10, 13, 15, 18 or 20, etc. Of course, Other values within the above ranges are also possible.
第四方面，本申请还提供了一种电化学装置，包括负极活性材料层，所述负极活性材料层包括上述第一方面所述的负极材料或上述第二方面所述的负极材料制备方法制得的负极材料。In a fourth aspect, the present application further provides an electrochemical device, comprising a negative electrode active material layer, the negative electrode active material layer comprising the negative electrode material described in the first aspect or the method for preparing the negative electrode material described in the second aspect above. obtained negative electrode material.
作为本申请可选的技术方案，电化学装置还包括正极极片，正极极片包括正极集流体和位于正极集流体上的正极活性材料层。As an optional technical solution of the present application, the electrochemical device further includes a positive electrode plate, and the positive electrode plate includes a positive electrode current collector and a positive electrode active material layer located on the positive electrode current collector.
作为本申请可选的技术方案，正极活性材料包括钴酸锂(LiCoO2)、锂镍锰钴三元材料、磷酸铁锂、磷酸锰铁锂、锰酸锂中的至少一种。As an optional technical solution of the present application, the positive active material includes at least one of lithium cobalt oxide (LiCoO2), lithium nickel manganese cobalt ternary material, lithium iron phosphate, lithium manganese iron phosphate, and lithium manganate.
作为本申请可选的技术方案，正极活性材料层还包括粘合剂和导电材料。可以理解地，粘合剂提高正极活性材料颗粒彼此间的结合，并且还提高正极活性材料与集流体的结合。As an optional technical solution of the present application, the positive electrode active material layer further includes a binder and a conductive material. Understandably, the binder improves the bonding of the positive electrode active material particles to each other, and also improves the bonding of the positive electrode active material to the current collector.
具体地，粘合剂包括聚乙烯醇、羟丙基纤维素、二乙酰基纤维素、聚氯乙烯、羧化的聚氯乙烯、聚氟乙烯、含亚乙基氧的聚合物、聚乙烯吡咯烷酮、聚氨酯、聚四氟乙烯、聚偏1,1-二氟乙烯、聚乙烯、聚丙烯、丁苯橡胶、丙烯酸(酯)化的丁苯橡胶、环氧树脂或尼龙中的至少一种。Specifically, the binder includes polyvinyl alcohol, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide-containing polymers, polyvinylpyrrolidone , at least one of polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylic (esterified) styrene-butadiene rubber, epoxy resin or nylon.
具体地，导电材料包括基于碳的材料、基于金属的材料、导电聚合物和它们的混合物。在一些实施例中，基于碳的材料选自天然石墨、人造石墨、碳黑、乙炔黑、科琴黑、碳纤维或其任意组合。在一些实施例中，基于金属的材料选自金属粉、金属纤维、铜、镍、铝或银。在一些实施例中，导电聚合物为聚亚苯基衍生物。Specifically, the conductive material includes carbon-based materials, metal-based materials, conductive polymers, and mixtures thereof. In some embodiments, the carbon-based material is selected from natural graphite, artificial graphite, carbon black, acetylene black, ketjen black, carbon fiber, or any combination thereof. In some embodiments, the metal-based material is selected from metal powders, metal fibers, copper, nickel, aluminum, or silver. In some embodiments, the conductive polymer is a polyphenylene derivative.
作为本申请可选的技术方案，正极集流体包括，但不限于：铝箔。As an optional technical solution of the present application, the positive electrode current collector includes, but is not limited to, aluminum foil.
作为本申请可选的技术方案，电化学装置还包括电解液，所述电解液包括有机溶剂、锂盐和添加剂。As an optional technical solution of the present application, the electrochemical device further includes an electrolyte, and the electrolyte includes an organic solvent, a lithium salt and an additive.
根据本申请的电解液的有机溶剂可为现有技术中已知的任何可作为电解液的溶剂的有机溶剂。根据本申请的电解液中使用的电解质没有限制，其可为现有技术中已知的任何电解质。根据本申请的电解液的添加剂可为现有技术中已知的任何可作为电解液添加剂的添加剂。The organic solvent of the electrolytic solution according to the present application may be any organic solvent known in the prior art that can be used as a solvent of the electrolytic solution. The electrolyte used in the electrolyte solution according to the present application is not limited, and it may be any electrolyte known in the prior art. The additive for the electrolyte according to the present application may be any additive known in the art as an additive for the electrolyte.
在具体实施例中，所述有机溶剂包括，但不限于：碳酸乙烯酯(EC)、碳酸丙烯酯(PC)、碳酸二乙酯(DEC)、碳酸甲乙酯(EMC)、碳酸二甲酯(DMC)、碳酸亚丙酯或丙酸乙酯。In a specific embodiment, the organic solvent includes, but is not limited to: ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC), propylene carbonate or ethyl propionate.
在具体实施例中，所述锂盐包括有机锂盐或无机锂盐中的至少一种。In a specific embodiment, the lithium salt includes at least one of an organic lithium salt or an inorganic lithium salt.
在具体实施例中，所述锂盐包括，但不限于：六氟磷酸锂(LiPF
6)、四氟硼酸锂(LiBF
4)、二氟磷酸锂(LiPO
2F
2)、双三氟甲烷磺酰亚胺锂LiN(CF
3SO
2)
2(LiTFSI)、双(氟磺酰)亚胺锂Li(N(SO
2F)
2)(LiFSI)、双草酸硼酸锂LiB(C
2O
4)
2(LiBOB)或二氟草酸硼酸锂LiBF
2(C
2O
4)(LiDFOB)。
In specific embodiments, the lithium salts include, but are not limited to: lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), lithium difluorophosphate (LiPO 2 F 2 ), bistrifluoromethanesulfonimide Lithium LiN(CF 3 SO 2 ) 2 (LiTFSI), Lithium Bis(fluorosulfonyl)imide Li(N(SO 2 F) 2 )(LiFSI), Lithium Bisoxalate Borate LiB(C 2 O 4 ) 2 (LiBOB) ) or lithium difluorooxalate borate LiBF 2 (C 2 O 4 ) (LiDFOB).
在具体实施例中，所述电解液中锂盐的浓度可以为0.5mol/L至3mol/L。In a specific embodiment, the concentration of the lithium salt in the electrolyte may be 0.5 mol/L to 3 mol/L.
作为本申请可选的技术方案，本申请的电化学装置包括，但不限于：所有种类的一次电池、二次电池、燃料电池、太阳能电池或电容。As an optional technical solution of the present application, the electrochemical device of the present application includes, but is not limited to: all kinds of primary batteries, secondary batteries, fuel cells, solar cells or capacitors.
在具体实施例中，所述电化学装置是锂二次电池，其中，锂二次电池包括，但不限于：锂金属二次电池、锂离子二次电池、锂聚合物二次电池或锂离子聚合物二次电池。In a specific embodiment, the electrochemical device is a lithium secondary battery, wherein the lithium secondary battery includes, but is not limited to, a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery, or a lithium ion secondary battery polymer secondary battery.
第五方面，本申请实施例还提供一种电子装置，电子装置包括上述第四方面所述的电化学装置。In a fifth aspect, an embodiment of the present application further provides an electronic device, where the electronic device includes the electrochemical device described in the fourth aspect.
作为本申请可选的技术方案，所述电子装置包括，但不限于：笔记本电脑、笔输入型计算机、移动电脑、电子书播放器、便携式电话、便携式传真机、便携式复印机、便携式打印机、头戴式立体声耳机、录像机、液晶电视、手提式清洁器、便携CD机、迷你光盘、收发机、电子记事本、计算器、存储卡、便携式录音机、收音机、备用电源、电机、汽车、摩托车、助力自行车、自行车、照明器具、玩具、游戏机、钟表、电动工具、闪光灯、照相机、家庭用大型蓄电池或锂离子电容器等。As an optional technical solution of the present application, the electronic devices include, but are not limited to: notebook computers, pen input computers, mobile computers, e-book players, portable telephones, portable fax machines, portable copiers, portable printers, headsets, etc. stereo headphones, VCRs, LCD TVs, portable cleaners, portable CD players, mini discs, transceivers, electronic notepads, calculators, memory cards, portable recorders, radios, backup power, motors, cars, motorcycles, power Bicycles, bicycles, lighting equipment, toys, game consoles, clocks, power tools, flashlights, cameras, large household batteries or lithium-ion capacitors, etc.
下面以锂离子电池为例并且结合具体的实施例说明锂离子电池的制备，本领域的技术人员将理解，本申请中描述的制备方法仅是实例，其他任何合适的制备方法均在本申请的范围内。The preparation of lithium ion batteries is described below by taking lithium ion batteries as an example and in conjunction with specific embodiments. Those skilled in the art will understand that the preparation methods described in this application are only examples, and any other suitable preparation methods are included in the scope of this application. within the range.
一、负极材料的制备1. Preparation of negative electrode materials
取100g干燥的抗生素菌渣研磨成粉末，以菌渣和金属盐质量比为(0.1-2)：1的比例加入到500ml去离子水中，混合均匀后置于110℃的烘箱中干燥，后在600℃-1000℃惰性气氛下碳化1h-3h，升温速率为1℃/min-10℃/min，得到固体物质。Take 100g of dried antibiotic slag and grind it into powder, add it to 500ml of deionized water in a ratio of (0.1-2):1 by mass ratio of the slag to metal salt, mix it evenly and place it in an oven at 110°C to dry, and then put it in an oven at 110°C. Carbonization at 600°C-1000°C for 1h-3h in an inert atmosphere with a heating rate of 1°C/min-10°C/min to obtain a solid substance.
将所述固体物质投入浓度为1mol/L-3mol/L酸溶液中，进行酸洗，保持搅拌1h-24h后，过滤去除金属杂质，得到氮掺杂多孔碳。The solid substance is put into an acid solution with a concentration of 1 mol/L to 3 mol/L, pickled, and kept stirring for 1 h to 24 h, and then filtered to remove metal impurities to obtain nitrogen-doped porous carbon.
将所述氮掺杂多孔碳置于管式炉中，在惰性气氛下，在400℃-600℃下进行硅烷气相沉积，沉积时间为0.5h-3h，硅烷浓度为2％-6％，得到活性材料。The nitrogen-doped porous carbon is placed in a tube furnace, and in an inert atmosphere, silane vapor deposition is performed at 400° C.-600° C., the deposition time is 0.5h-3h, and the silane concentration is 2%-6% to obtain active material.
将所述活性材料和适量碳源分散在液相体系中，在剪切搅拌机中保持搅拌0.5h-12h，混合均匀，干燥后，在惰性气氛下进行烧结，烧结温度为500℃-1200℃，升温速率为1℃/min-10℃/min，保温时间为1h-24h。Disperse the active material and an appropriate amount of carbon source in the liquid phase system, keep stirring in a shear mixer for 0.5h-12h, mix evenly, and after drying, sinter in an inert atmosphere, and the sintering temperature is 500°C-1200°C, The heating rate is 1°C/min-10°C/min, and the holding time is 1h-24h.
根据上述方法制备实施例1至9，实施例1至9的具体参数见下表1。Examples 1 to 9 were prepared according to the above method, and the specific parameters of Examples 1 to 9 are shown in Table 1 below.
进一步地，根据上述方法制备对比例1，对比例1的制成的多孔碳纤维骨架的长 径比为1.0，对比例1的具体参数见下表1。Further, Comparative Example 1 was prepared according to the above method, and the aspect ratio of the porous carbon fiber skeleton prepared in Comparative Example 1 was 1.0. The specific parameters of Comparative Example 1 are shown in Table 1 below.
进一步地，根据上述方法制备对比例2，对比例2的制备过程中，混合溶液没有采纺丝工艺制成聚合纤维，而是制成块状聚合物，制成的负极材料中的碳骨架呈球形状。对比例2的具体参数见下表1。Further, prepare comparative example 2 according to the above-mentioned method, in the preparation process of comparative example 2, the mixed solution does not adopt spinning process to make polymer fiber, but makes bulk polymer, and the carbon skeleton in the made negative electrode material is ball shape. The specific parameters of Comparative Example 2 are shown in Table 1 below.
表1.负极材料性能参数Table 1. Anode material performance parameters
二、负极材料的性能测试：2. Performance test of negative electrode material:
(1)扣电测试:(1) Deduction test:
将负极材料、导电炭黑与聚合物按照质量比80：10：10加去离子水经过搅成浆料，利用刮刀涂成100um厚度的涂层，85℃经过12小时真空干燥箱烘干后，利用在干燥环境中用冲压机切成直径为1cm的圆片，在手套箱中以金属锂片作为对电极，隔离膜选择ceglard复合膜，加入电解液组装成扣式电池。运用蓝电(LAND)系列电池测试测试对电池进行充放电测试，测试其充放电性能。The negative electrode material, conductive carbon black and polymer were added with deionized water according to the mass ratio of 80:10:10, stirred into a slurry, coated with a scraper to form a coating with a thickness of 100um, and dried in a vacuum drying oven at 85°C for 12 hours. Using a punching machine in a dry environment to cut into 1 cm diameter circles, in a glove box, metal lithium sheets were used as counter electrodes, ceglad composite membranes were selected as separators, and an electrolyte solution was added to assemble a button battery. Use the LAND series battery test test to test the charge and discharge of the battery to test its charge and discharge performance.
(2)比表面积测试：(2) Specific surface area test:
在恒温低温下，测定不同相对压力时的气体在固体表面的吸附量后，基于布朗诺尔-埃特-泰勒吸附理论及其公式(BET公式)求得试样单分子层吸附量，从而计算出固体的比表面积。At a constant temperature and low temperature, after measuring the adsorption amount of gas on the solid surface at different relative pressures, the adsorption amount of the sample monolayer is calculated based on the Brownnauer-Etter-Taylor adsorption theory and its formula (BET formula), and then calculate The specific surface area of a solid.
BET公式：
BET formula:
其中：W-相对压力下固体样品所吸附的气体的质量；Among them: W-mass of gas adsorbed by solid sample under relative pressure;
Wm-铺满一单分子层的气体饱和吸附量；Wm - the gas saturation adsorption capacity covering a monolayer;
斜率：(c-1)/(WmC)，截距：1/WmC，总比表面积：(Wm*N*Acs/M)，比表面积：S＝St/m，其中m为样品质量，Acs：每个N
2分子的所占据的平均面积
Slope: (c-1)/(WmC), intercept: 1/WmC, total specific surface area: (Wm*N*Acs/M), specific surface area: S=St/m, where m is the sample mass, Acs: Average area occupied by each N molecule
称取1.5g至3.5g负极材料粉末样品装入TriStar II 3020的测试样品管中，200℃脱气120min后进行测试。Weigh 1.5g to 3.5g of negative electrode material powder samples into the test sample tube of TriStar II 3020, and test after degassing at 200°C for 120min.
(3)粒径测试：(3) Particle size test:
50ml洁净烧杯中加入约0.02g粉末样品，加入约2 0ml去离子水，再滴加几滴1％的表面活性剂，使粉末完全分散于水中，120W超声清洗机中超声5min，利用MasterSizer 2000测试粒径分布。Add about 0.02g of powder sample to a 50ml clean beaker, add about 20ml of deionized water, and then add a few drops of 1% surfactant to completely disperse the powder in the water, ultrasonic for 5min in a 120W ultrasonic cleaner, and use MasterSizer 2000 to test Particle size distribution.
(4)负极材料的硅含量的测试方法：(4) Test method for silicon content of negative electrode material:
先对样品进行碳含量测试，100％减去测试得到的值即为硅含量百分比。其中，碳含量测试如下：The carbon content test is performed on the sample first, and the value obtained by subtracting the test from 100% is the silicon content percentage. Among them, the carbon content test is as follows:
负极材料样品在富氧条件下由高频炉高温加热燃烧使碳、硫氧化成二氧化碳、二氧化硫，该气体经处理后进入相应的吸收池，对相应的红外辐射进行吸收再由探测器转化成对应的信号。此信号由计算机采样，经线性校正后转换成与二氧化碳、二氧化硫浓度成正比的数值，然后把整个分析过程的取值累加，分析结束后，此累加值在计算机中除以重量值，再乘以校正系数，扣除空白，即可获得样品中碳、硫百分含量。利用高频红外碳硫分析仪(上海徳凯HCS-140)进行样品测试。The negative electrode material sample is heated and combusted by a high-frequency furnace under oxygen-enriched conditions to oxidize carbon and sulfur into carbon dioxide and sulfur dioxide. signal of. This signal is sampled by the computer, converted into a value proportional to the concentration of carbon dioxide and sulfur dioxide after linear correction, and then the value of the whole analysis process is accumulated. After the analysis, the accumulated value is divided by the weight value in the computer, and then multiplied by Correction coefficient, subtract the blank, you can obtain the percentage of carbon and sulfur in the sample. Samples were tested using a high-frequency infrared carbon-sulfur analyzer (Shanghai Dekai HCS-140).
(5)负极材料的粉体导电率测试：(5) Powder conductivity test of negative electrode material:
采用电阻率测试仪(苏州晶格电子ST-2255A)，取5g粉末样品，用电子压力机恒压至5000kg±2kg，维持15-25s，将样品置于测试仪电极间，样品高度h(cm)，两端电压U，电流I，电阻R(KΩ)粉压片后的面积S＝3.14cm
2，根据公式δ＝h/(S*R)/1000计算得到粉末电子电导率，单位为S/m。
Using a resistivity tester (Suzhou Lattice Electronics ST-2255A), take a 5g powder sample, use an electronic press to constant pressure to 5000kg ± 2kg, maintain for 15-25s, place the sample between the electrodes of the tester, and the sample height is h (cm ), voltage U at both ends, current I, resistance R (KΩ) The area S=3.14cm 2 after the powder is pressed, and the electronic conductivity of the powder is calculated according to the formula δ=h/(S*R)/1000, the unit is S /m.
(6)氮掺杂多孔碳的氮含量测试：(6) Nitrogen content test of nitrogen-doped porous carbon:
氮元素含量测定采用意大利VELP公司生产的型号为CN 802碳氮元素分析仪，以TCD检测器作为N素检测器，在氩气气氛下，1030℃条件下检测，功率为1400W。The nitrogen element content was measured using the CN 802 carbon and nitrogen element analyzer produced by Italian VELP Company, and the TCD detector was used as the N element detector.
(7)拉曼测试：(7) Raman test:
拉曼光谱测定采用的是Jobin Yvon LabRAM HR光谱仪，光源为532nm，测试范围为0cm
-1～4000cm
-1。测试范围为100μm*100μm，通过统计100个I
D/I
G值得到I
D/I
G平均值。
The Raman spectrum was measured using a Jobin Yvon LabRAM HR spectrometer with a light source of 532 nm and a test range of 0 cm -1 to 4000 cm -1 . The test range is 100 μm*100 μm, and the average value of ID / IG is obtained by counting 100 ID / IG values .
(8)XPS测试：(8) XPS test:
XPS测试设备为赛默飞公司的ESCLAB 250Xi，以Al为靶做激发源，功率250w，真空度＞10-9Pa。通过XPS测试确定氮掺杂多孔碳中的氮的构型。The XPS test equipment is ESCLAB 250Xi from Thermo Fisher Scientific, with Al as the target as the excitation source, the power is 250w, and the vacuum degree is more than 10-9Pa. The configuration of nitrogen in nitrogen-doped porous carbon was determined by XPS testing.
(9)孔隙率测试：(9) Porosity test:
采用气体置换法测试所述负极材料和负极极片的孔隙率。计算方法：样品孔体积占总面积的百分比，P＝(V-V0)/V*100％，V0：真体积，V：表观体积。The porosity of the negative electrode material and negative electrode sheet was tested by gas displacement method. Calculation method: the percentage of sample pore volume to the total area, P=(V-V0)/V*100%, V0: true volume, V: apparent volume.
(10)负极材料的横断面测试：(10) Cross-sectional test of negative electrode material:
截面抛光仪采用离子源将惰性气体电离产生惰性离子，经过加速、聚焦后，高速惰性离子将样品表面的原子或分子撞击出去，实现离子抛光。经CP切割后，将样品放到SEM专用样品台上，进行SEM测试。仪器型号IB-09010CP，离子加速电压2-6kV，使用气体为氩气。通过横断面测试将所述硅碳负极材料切割后，可测试截面处含硅材料层厚度D
0、外层碳层厚度D
2以及多孔碳的壁厚。
The cross-section polisher uses an ion source to ionize an inert gas to generate inert ions. After acceleration and focusing, the high-speed inert ions knock out atoms or molecules on the surface of the sample to achieve ion polishing. After being cut by CP, the sample was placed on the SEM special sample stage for SEM test. The instrument model is IB-09010CP, the ion accelerating voltage is 2-6kV, and the gas used is argon. After the silicon carbon anode material is cut through the cross section test, the thickness D 0 of the silicon-containing material layer, the thickness D 2 of the outer carbon layer and the wall thickness of the porous carbon at the cross section can be tested.
(11)TEM测试：(11) TEM test:
透射电镜表征在日本电子JEOL JEM-2010透射电子显微镜上进行，操作电压为200kV，观察负极材料的结构，如图1所示。Transmission electron microscopy characterization was performed on a JEOL JEM-2010 transmission electron microscope with an operating voltage of 200 kV, and the structure of the negative electrode material was observed, as shown in Figure 1.
(12)孔体积测试：(12) Pore volume test:
称取1.5g至3.5g粉末样品装入TriStar II 3020的测试样品管中，200℃脱气120min后进行测试。由相对压力(P/Po)为0.99的吸附量(V
STP,cm
3g
-1)估算得出孔体积
Weigh 1.5g to 3.5g powder samples into the test sample tube of TriStar II 3020, and test after degassing at 200°C for 120min. Pore volume was estimated from the adsorption capacity (V STP , cm 3 g -1 ) at a relative pressure (P/Po) of 0.99
(13)氮掺杂多孔碳的孔径测试方法：(13) Pore size test method of nitrogen-doped porous carbon:
称取1.5g至3.5g氮掺杂多孔碳粉末样品装入TriStar II 3020的测试样品管中，200℃脱气120min后进行测试。通过BJH法使用吸附数据计算得到孔径分布。Weigh 1.5g to 3.5g of nitrogen-doped porous carbon powder samples into the test sample tube of TriStar II 3020, and test after degassing at 200°C for 120min. The pore size distribution was calculated by the BJH method using adsorption data.
(14)碳层的质量百分比含量测试方法：(14) Test method for mass percentage content of carbon layer:
分别利用测试方法(4)测得未经碳复合的硅碳内核中硅含量，即得硅质量含量与氮掺杂多孔碳的质量含量之间的数学关系，再用同样的方式测得负极材料中硅的质量百分含量，结合硅与氮掺杂多孔碳之间的质量百分含量关系，即得碳层的质量百分比含量。Test method (4) is used to measure the silicon content in the silicon-carbon core without carbon compounding, that is, to obtain the mathematical relationship between the mass content of silicon and the mass content of nitrogen-doped porous carbon, and then use the same method to measure the negative electrode material. The mass percentage content of silicon in the middle is combined with the mass percentage content relationship between silicon and nitrogen-doped porous carbon, that is, the mass percentage content of the carbon layer is obtained.
(15)氮掺杂多孔碳的质量百分比含量测试方法：(15) Test method for mass percentage content of nitrogen-doped porous carbon:
分别利用测试方法(4)测得未经碳复合的硅碳内核中硅含量，即得硅质量含量与氮掺杂多孔碳的质量含量之间的数学关系，再用同样的方式测得负极材料中硅的质量百分含量，结合硅与氮掺杂多孔碳之间的质量百分含量关系，即得掺杂多孔碳的质量百分比含量。Test method (4) is used to measure the silicon content in the silicon-carbon core without carbon compounding, that is, to obtain the mathematical relationship between the mass content of silicon and the mass content of nitrogen-doped porous carbon, and then use the same method to measure the negative electrode material. The mass percentage content of silicon in the medium is combined with the mass percentage content relationship between silicon and nitrogen-doped porous carbon to obtain the mass percentage content of the doped porous carbon.
三、负极极片的制备3. Preparation of negative pole pieces
将上述实施例以及对比例的负极材料、石墨、导电剂(导电炭黑、Super
)和粘结剂PAA按照重量比70：15：5：10进行混合，加入去离子水，在真空搅拌机作用下获得负极浆料；将负极浆料均匀涂覆在负极集流体铜箔上；将铜箔烘干，然后经过5t压力进行冷压、裁片、分切后，在真空条件下干燥，得到负极极片。
The negative electrode materials, graphite, conductive agent (conductive carbon black, Super ) and binder PAA are mixed according to the weight ratio of 70:15:5:10, deionized water is added, and the negative electrode slurry is obtained under the action of a vacuum mixer; the negative electrode slurry is uniformly coated on the negative electrode current collector copper foil; The copper foil is dried, and then subjected to cold pressing, cutting, and slitting under a pressure of 5t, and then dried under vacuum conditions to obtain a negative pole piece.
四、负极极片的性能测试：Fourth, the performance test of the negative pole piece:
(1)负极活性材料层的压实密度测试：(1) Compaction density test of negative electrode active material layer:
负极活性材料层的压实密度PD＝m/V，m表示负极活性材料层的重量，V表示负极活性材料层的体积，m可使用精度为0.01g以上的电子天平称量得到，负极活性材料层的表面积与厚度的乘积即为负极活性材料层的体积V，其中厚度可使用精度为0.5μm的螺旋千分尺测量得到。The compaction density of the negative electrode active material layer PD=m/V, m represents the weight of the negative electrode active material layer, V represents the volume of the negative electrode active material layer, m can be obtained by weighing with an electronic balance with an accuracy of more than 0.01g, and the negative electrode active material The product of the surface area and thickness of the layer is the volume V of the negative active material layer, where the thickness can be measured using a screw micrometer with an accuracy of 0.5 μm.
(2)负极活性材料层的OI值测试：(2) OI value test of negative electrode active material layer:
负极活性材料层的OI值可通过使用X射线粉末衍射仪(X'pert PRO)得到，依据X射线衍射分析法通则以及石墨的点阵参数测定方法JIS K 0131-1996、JB/T4220-2011，得到X射线衍射谱图，OI值＝C
004/C
110，其中，C
004为004特征衍射峰的峰面积，C
110为110特征衍射峰的峰面积。
The OI value of the negative electrode active material layer can be obtained by using an X-ray powder diffractometer (X'pert PRO), according to the general rules of X-ray diffraction analysis and the method for measuring lattice parameters of graphite JIS K 0131-1996, JB/T4220-2011, The X-ray diffraction spectrum is obtained, OI value=C 004 /C 110 , wherein C 004 is the peak area of the 004 characteristic diffraction peak, and C 110 is the peak area of the 110 characteristic diffraction peak.
(3)负极活性材料层的电阻测试：(3) Resistance test of negative electrode active material layer:
采用四探针法测试负极活性材料层电阻，四探针法测试所用仪器为精密直流电压电流源(SB118型)，四只长1.5cm*宽1cm*厚2mm的铜板被等距固定在一条线上，中间两块铜板的间距为L(1-2cm)，固定铜板的基材为绝缘材料。测试时将四只铜板下端面压在所测负极上(压力为3000Kg)，维持时间60s，两端铜板接通直流电流I，在中间两只铜板测取电压V，读取三次I和V值，分别取I和V的平均值Ia和Va，Va/Ia的值即为测试处的负极活性材料层的电阻。每张负极极片取12个点测试，取平均值。The resistance of the negative electrode active material layer is measured by the four-point probe method. The instrument used in the four-point probe method is a precision DC voltage and current source (SB118 type). Four copper plates with a length of 1.5cm*width of 1cm*2mm of thickness are fixed on a line at equal distances. Above, the distance between the two middle copper plates is L (1-2cm), and the base material for fixing the copper plates is an insulating material. During the test, press the lower end face of the four copper plates on the negative electrode to be measured (the pressure is 3000Kg) for 60s. The copper plates at both ends are connected to the DC current I, and the voltage V is measured on the two copper plates in the middle, and the values of I and V are read three times. , take the average values Ia and Va of I and V respectively, and the value of Va/Ia is the resistance of the negative electrode active material layer at the test place. Take 12 test points for each negative pole piece and take the average value.
(4)负极活性材料层的孔隙率测试：(4) Porosity test of negative electrode active material layer:
采用气体置换法测试所述负极活性材料层的孔隙率。计算方法：样品孔体积占总面积的百分比，P＝(V-V
0)/V*100％，V
0为材料层的真体积，V为表观体积。
The porosity of the negative electrode active material layer was tested by a gas displacement method. Calculation method: the percentage of sample pore volume to the total area, P=(VV 0 )/V*100%, V 0 is the true volume of the material layer, and V is the apparent volume.
五、锂电池的制备5. Preparation of Lithium Batteries
(1)正极极片的制备(1) Preparation of positive electrode sheet
将正极活性材料钴酸锂(LiCoO
2)、导电炭黑、粘结剂聚偏二氟乙烯按照重量比95：2.5：2.5进行混合，加入N-甲基吡咯烷酮(NMP)，在真空搅拌机作用下搅拌均匀，获得正极浆料；将正极浆料均匀涂覆于正极集流体铝箔上；将铝箔烘干，然后经过冷压、裁片、分切后，在真空条件下干燥，得到正极极片。
The positive active material lithium cobalt oxide (LiCoO 2 ), conductive carbon black, and binder polyvinylidene fluoride are mixed according to the weight ratio of 95:2.5:2.5, and N-methylpyrrolidone (NMP) is added. Under the action of a vacuum mixer Stir evenly to obtain a positive electrode slurry; uniformly coat the positive electrode slurry on the aluminum foil of the positive electrode current collector; dry the aluminum foil, and then after cold pressing, cutting and slitting, it is dried under vacuum conditions to obtain a positive electrode pole piece.
(2)负极极片的制备(2) Preparation of negative pole piece
将上述实施例以及对比例的负极材料、石墨、导电剂(导电炭黑、Super
)和粘结剂PAA按照重量比70：15：5：10进行混合，加入去离子水，在真空搅拌机作用下获得负极浆料；将负极浆料均匀涂覆在负极集流体铜箔上；将铜箔烘干，然后经过冷压、裁片、分切后，在真空条件下干燥，得到负极极片。
The negative electrode materials, graphite, conductive agent (conductive carbon black, Super ) and binder PAA are mixed according to the weight ratio of 70:15:5:10, deionized water is added, and the negative electrode slurry is obtained under the action of a vacuum mixer; the negative electrode slurry is uniformly coated on the negative electrode current collector copper foil; The copper foil is dried, then subjected to cold pressing, cutting and slitting, and then dried under vacuum conditions to obtain a negative pole piece.
(3)电解液(3) Electrolyte
在干燥的氩气气氛手套箱中，往碳酸丙烯酯(PC)、碳酸乙烯酯(EC)、碳酸二乙酯(DEC)(重量比约1：1：1)混合而成的溶剂中，加入LiPF6混合均匀，其中LiPF6的浓度为约1.15mol/L，混合均匀得到电解液。In a dry argon atmosphere glove box, add propylene carbonate (PC), ethylene carbonate (EC), and diethyl carbonate (DEC) (weight ratio of about 1:1:1) to a solvent mixed with LiPF6 is mixed evenly, wherein the concentration of LiPF6 is about 1.15 mol/L, and the electrolyte is obtained by mixing evenly.
(3)隔离膜(3) Isolation film
以聚乙烯多孔聚合薄膜作为隔离膜。A polyethylene porous polymer film is used as the separator.
(4)锂离子电池的制备(4) Preparation of lithium ion battery
将正极极片、隔离膜、负极极片按顺序叠好，使隔离膜处于正、负极片之间起到隔离的作用，然后卷绕得到裸电芯；焊接极耳后将裸电芯置于外包装箔铝塑膜中，将上述制备好的电解液注入到干燥后的裸电芯中，经过真空封装、静置、化成、整形、容量测试等工序，获得锂离子电池。Stack the positive pole piece, the separator and the negative pole piece in order, so that the separator is placed between the positive and negative pole pieces to play the role of isolation, and then roll up to obtain a bare cell; after welding the tabs, place the bare cell on the In the outer packaging foil aluminum-plastic film, the above-prepared electrolyte is injected into the dried bare cell, and the lithium-ion battery is obtained through the processes of vacuum packaging, standing, forming, shaping, and capacity testing.
六、锂电池的性能测试：6. Performance test of lithium battery:
(1)锂离子电池循环性能测试(1) Lithium-ion battery cycle performance test
将锂离子电池置于45℃(25℃)恒温箱中，静置30分钟，使锂离子电池达到恒 温。将达到恒温的锂离子电池以0.7C恒流充电至电压为4.4V，然后以4.4V恒压充电至电流为0.025C，静置5分钟后以0.5C恒流放电至电压为3.0V，以此步骤得到的容量为初始容量，进行0.7C充电/0.5C放电进行循环测试，以每一步的容量与初始容量做比值，得到容量衰减曲线。以25℃循环截至到容量保持率为90％的圈数记为电池的室温循环性能，以45℃循环截至到容量保持率为80％的圈数记为电池的高温循环性能，通过比较上述两种情况下的循环圈数比较材料的循环性能。Place the lithium-ion battery in a 45°C (25°C) incubator for 30 minutes to allow the lithium-ion battery to reach a constant temperature. The lithium-ion battery that has reached a constant temperature is charged with a constant current of 0.7C to a voltage of 4.4V, and then charged with a constant voltage of 4.4V to a current of 0.025C. After standing for 5 minutes, it is discharged with a constant current of 0.5C to a voltage of 3.0V. The capacity obtained in this step is the initial capacity, and 0.7C charge/0.5C discharge is carried out for cycle test, and the capacity decay curve is obtained by taking the ratio of the capacity in each step to the initial capacity. The room temperature cycle performance of the battery was recorded as the number of cycles from 25°C to 90% of the capacity retention rate, and the number of cycles from 45°C to 80% of the capacity retention rate was recorded as the high-temperature cycle performance of the battery. The number of cycles in each case compares the cycle performance of the materials.
(2)放电倍率测试：(2) Discharge rate test:
将锂离子电池置于25℃恒温箱中，静置30分钟，使锂离子电池达到恒温。将达到恒温的锂离子电池以0.2C恒流放电至电压为3.0V，静置5min，以0.5C恒流充电到电压为4.45V，然后以4.45V恒压充电到电流为0.05C后静置5min，调整放电倍率，分别以0.2C、0.5C、1C、1.5C、2.0C进行放电测试，分别得到放电容量，以每个倍率下得到的容量与0.2C得到的容量对比，通过比较2C与0.2C下的比值比较倍率性能。Place the lithium-ion battery in a 25°C incubator for 30 minutes so that the lithium-ion battery reaches a constant temperature. Discharge the lithium-ion battery that has reached a constant temperature with a constant current of 0.2C to a voltage of 3.0V, let it stand for 5 minutes, charge it with a constant current of 0.5C to a voltage of 4.45V, and then charge it with a constant voltage of 4.45V to a current of 0.05C, then let it stand. 5min, adjust the discharge rate, conduct the discharge test at 0.2C, 0.5C, 1C, 1.5C, 2.0C, respectively, to obtain the discharge capacity, and compare the capacity obtained at each rate with the capacity obtained at 0.2C. The ratio at 0.2C compares rate performance.
(3)电池满充膨胀率测试：(3) Battery full charge expansion rate test:
用螺旋千分尺测试半充(50％充电状态(SOC))时新鲜电池的厚度，循环至400圈时，电池处于满充(100％SOC)状态下，再用螺旋千分尺测试此时电池的厚度，与初始半充(50％SOC)时新鲜电池的厚度对比，即可得此时满充(100％SOC)电池膨胀率。Use a screw micrometer to test the thickness of the fresh battery when it is half-charged (50% state of charge (SOC)). When the cycle reaches 400 cycles, the battery is in a fully charged (100% SOC) state, and then use a screw micrometer to test the thickness of the battery at this time. Comparing with the thickness of the fresh battery at the initial half-charge (50% SOC), the expansion rate of the fully charged (100% SOC) battery at this time can be obtained.
根据上述方法制得的实施例1至9的负极材料及对比例1的负极材料性能参数见表1，其制得的锂电池的性能测试结果见表2所示。The performance parameters of the negative electrode materials of Examples 1 to 9 and the negative electrode material of Comparative Example 1 prepared according to the above method are shown in Table 1, and the performance test results of the prepared lithium batteries are shown in Table 2.
表2Table 2
从实施例1至3的测试结果可以看出，在氮掺杂多孔碳孔径、碳层的厚度和氮含量一致的前提下，随着沉积在氮掺杂多孔碳上的硅含量的增加，实施例1至3的负极材料的克容量也逐步上升，然而纳米含硅材料层厚度的增加，会提升电池膨胀率，直 至硅膨胀破坏孔结构和外层的碳层，引起循环的快速衰减。如实施例3所示，当含硅材料层厚度增加到10nm厚时，循环性能、膨胀率和倍率性能均会得到恶化；对比例1则直接说明了当达到75.9％的高硅含量下，硅颗粒膨胀很容易引起负极材料结构的破坏，进而导致其循环性能衰减严重。优选地，所述负极材料中的硅的质量百分比含量为32.4％至52.5％。From the test results of Examples 1 to 3, it can be seen that under the premise that the pore size of the nitrogen-doped porous carbon, the thickness of the carbon layer and the nitrogen content are consistent, with the increase of the silicon content deposited on the nitrogen-doped porous carbon, the The gram capacity of the negative electrode materials in Examples 1 to 3 also increased gradually. However, the increase in the thickness of the nano-silicon-containing material layer would increase the cell expansion rate until the silicon expansion destroyed the pore structure and the outer carbon layer, causing rapid cycle decay. As shown in Example 3, when the thickness of the silicon-containing material layer is increased to 10 nm, the cycle performance, expansion ratio and rate performance will be deteriorated; Comparative Example 1 directly shows that when the high silicon content reaches 75.9%, silicon Particle expansion can easily lead to the destruction of the anode material structure, which in turn leads to a serious degradation of its cycle performance. Preferably, the mass percentage content of silicon in the negative electrode material is 32.4% to 52.5%.
从实施例3至5的测试结果可以看出，在负极材料的硅含量、含硅材料层厚度D
0、碳层厚度D
2和氮含量一致的前提下，实施例3至5的氮掺杂多孔碳孔径D
1逐步增大，可以为硅膨胀预留出更加充分的空间，以获得更加稳定的结构，进而表现出较好的循环性能，如实施例5所示，当孔径增加到20nm，电池的循环性能、膨胀率和倍率性能均得到了改善。对比例2将硅颗粒直接沉积在没有孔的碳基体上，硅颗粒的膨胀会引起循环性能的快速衰减，因此采用多孔结构的氮掺杂多孔碳，可以有效缓解硅颗粒的膨胀引起的循环性能的衰减。
From the test results of Examples 3 to 5, it can be seen that under the premise that the silicon content of the negative electrode material, the thickness D 0 of the silicon-containing material layer, the thickness D 2 of the carbon layer and the nitrogen content are consistent, the nitrogen doping of Examples 3 to 5 The pore diameter D1 of the porous carbon gradually increases, which can reserve more sufficient space for the expansion of silicon to obtain a more stable structure, thereby showing better cycle performance. As shown in Example 5, when the pore diameter increases to 20 nm, The cycling performance, swelling ratio, and rate capability of the battery were all improved. Comparative Example 2 Silicon particles are directly deposited on a carbon matrix without pores. The expansion of silicon particles will cause rapid decay of cycle performance. Therefore, the use of nitrogen-doped porous carbon with a porous structure can effectively alleviate the cycle performance caused by the expansion of silicon particles. attenuation.
从实施例2、6及7的测试结果可以看出，在负极材料的硅含量、含硅材料层厚度D
0、氮掺杂多孔碳孔径D
1和氮含量一致的前提下，实施例6、2及7的碳层的厚度D
2逐步增加，可以看出提高碳层的厚度，可以有效缓解内部硅颗粒膨胀引起的应力，在充放电过程中保持结构的稳定性，同时能有效隔绝电解液，避免硅颗粒和电解液之间发生副反应，而过分提高外层碳层厚度，则增加了离子和电子的传输距离，不利于发挥倍率性能，同时不利于发挥硅高能量的优势。如实施例6、7所示，当碳层的厚度降低至2nm和增加到20nm时，电池的循环性能、膨胀率和倍率性能均有所下降；对比例3的氮掺杂多孔碳的外层没有碳层时，在循环过程内部硅颗粒膨胀产生的应力可能会破坏结构，同时硅和电解液间发生副反应也会引起循环的快速衰减。
From the test results of Examples 2, 6 and 7, it can be seen that under the premise that the silicon content of the negative electrode material, the thickness D 0 of the silicon-containing material layer, the pore diameter D 1 of the nitrogen-doped porous carbon and the nitrogen content are consistent, Example 6, The thickness D 2 of the carbon layer of 2 and 7 gradually increases. It can be seen that increasing the thickness of the carbon layer can effectively relieve the stress caused by the expansion of the internal silicon particles, maintain the stability of the structure during the charging and discharging process, and effectively isolate the electrolyte. , to avoid side reactions between the silicon particles and the electrolyte, and excessively increasing the thickness of the outer carbon layer increases the transmission distance of ions and electrons, which is not conducive to the rate performance and the high energy advantage of silicon. As shown in Examples 6 and 7, when the thickness of the carbon layer was reduced to 2 nm and increased to 20 nm, the cycle performance, expansion rate and rate performance of the battery all decreased; the outer layer of nitrogen-doped porous carbon of Comparative Example 3 In the absence of a carbon layer, the stress generated by the expansion of the silicon particles inside the cycling process may destroy the structure, and the side reactions between the silicon and the electrolyte can also cause rapid cycle decay.
从实施例2、8及9的测试结果可以看出，在负极材料的硅含量、含硅材料层厚度D
0、氮掺杂多孔碳孔径D
1和外层碳层厚度一致的前提下，实施例8、2及9的氮含量逐步增加，提高氮含量有利于提高多孔碳中的氮原子和硅颗粒之间的相互作用力，提高硅的附着力，避免硅颗粒在硅负极充放电过程中因体积膨胀从碳基体上脱落而失去电接触，并且掺杂氮可以扰乱碳原子的共轭电子体系，提供更大电化学活性面积和活性位点，协同促进碳原子与杂化原子间电荷转移，提升碳材料导电率和比容量，但较高的氮含量会破坏碳基体的有序结构，降低碳基体的结构稳定性，如实施例8、9所示，当氮含量降低到3％和增加到8％时，电池的循环性能、膨胀率和倍率性能均有所下降；对比例4中的多孔碳没有掺杂氮，负极材料的容量、倍率和循环性能都大幅降低。
It can be seen from the test results of Examples 2, 8 and 9 that under the premise that the silicon content of the negative electrode material, the thickness D 0 of the silicon-containing material layer, the pore diameter D 1 of the nitrogen-doped porous carbon and the thickness of the outer carbon layer are consistent, the The nitrogen content of Examples 8, 2 and 9 is gradually increased. Increasing the nitrogen content is beneficial to improve the interaction force between the nitrogen atoms in the porous carbon and the silicon particles, improve the adhesion of silicon, and avoid the silicon particles in the process of charging and discharging the silicon negative electrode. The electrical contact is lost due to the volume expansion from the carbon matrix, and the doping of nitrogen can disturb the conjugated electron system of carbon atoms, provide a larger electrochemical active area and active sites, and synergistically promote the charge transfer between carbon atoms and hybrid atoms. , improve the conductivity and specific capacity of carbon materials, but higher nitrogen content will destroy the ordered structure of the carbon matrix and reduce the structural stability of the carbon matrix. As shown in Examples 8 and 9, when the nitrogen content is reduced to 3% and When it increased to 8%, the cycle performance, expansion rate and rate performance of the battery decreased; the porous carbon in Comparative Example 4 was not doped with nitrogen, and the capacity, rate and cycle performance of the negative electrode material were greatly reduced.
根据上述方法制得的实施例10至15的负极材料，其中，负极材料中的硅的质量百分比含量均为50％，含硅材料层的厚度D
0为10nm，所述含硅材料层的厚度D
0与所述氮掺杂多孔碳的孔径D
1的比值D
0/D
1均为0.7，其他性能参数见表3-1所示，其制得的锂电池的性能测试结果见表3-2所示。
The negative electrode materials of Examples 10 to 15 prepared according to the above method, wherein the mass percentage content of silicon in the negative electrode material is all 50%, the thickness D 0 of the silicon-containing material layer is 10 nm, and the thickness of the silicon-containing material layer is 10 nm. The ratio D 0 /D 1 of D 0 to the pore diameter D 1 of the nitrogen-doped porous carbon is both 0.7, other performance parameters are shown in Table 3-1, and the performance test results of the lithium battery prepared are shown in Table 3- 2 shown.
表3-1Table 3-1
表3-2Table 3-2
从实施例10至12的测试结果可以看出，在保持颗粒平均粒径和其他条件不变的前提下，提高外层碳层厚度，负极材料的粉末电导率提高了，受碳层是厚度增加的影响，负极材料的整体I
D/I
G值降低，提高碳层厚度后，对内核活性材料的结合性更好，负极材料的孔体积降低了，外层碳层的表面孔体积的降低，有利于隔绝电解液，形成稳定的SEI膜，碳层厚度的提高有利于加强对硅碳内核膨胀应力的束缚，当实施例12中，碳层厚度到15nm时，电池表现出了较好的电化学性能，但是也不能一味的增加碳层的厚度，否则会降低负极材料的硅含量，降低负极材料的能量密度。
From the test results of Examples 10 to 12, it can be seen that under the premise of keeping the average particle size of the particles and other conditions unchanged, the thickness of the outer carbon layer is increased, the powder conductivity of the negative electrode material is improved, and the thickness of the carbon-receiving layer is increased. Influenced by the influence of , the overall ID/ IG value of the negative electrode material decreases. After increasing the thickness of the carbon layer, the bonding to the inner core active material is better, the pore volume of the negative electrode material decreases, and the surface pore volume of the outer carbon layer decreases. It is beneficial to isolate the electrolyte and form a stable SEI film. The increase of the thickness of the carbon layer is beneficial to strengthen the restraint of the expansion stress of the silicon carbon core. Chemical properties, but the thickness of the carbon layer cannot be blindly increased, otherwise the silicon content of the negative electrode material will be reduced, and the energy density of the negative electrode material will be reduced.
从实施例11、13、14、15的测试结果可以看出，在保持碳层厚度和其他条件不变的前提下，增加颗粒的平均粒径，较大的颗粒会引起较大的膨胀，易于造成极片粉化问题，使负极材料从负极极片中脱落，引起电化学性能的快速衰减，实施例15中则直接说明了当所述负极材料颗粒平均粒径增加到60um时，电池表现出了较差的电化学性能。From the test results of Examples 11, 13, 14, and 15, it can be seen that, on the premise of keeping the thickness of the carbon layer and other conditions unchanged, increasing the average particle size of the particles, larger particles will cause larger expansion, easy to Causes the problem of pulverization of the pole piece, which makes the negative electrode material fall off from the negative pole piece, causing the rapid decay of the electrochemical performance. poor electrochemical performance.
根据上述方法制得的实施例16至25的负极材料，其制得的锂电池的性能测试结果见表所示。For the negative electrode materials of Examples 16 to 25 prepared according to the above method, the performance test results of the prepared lithium batteries are shown in the table.
表4-1Table 4-1
表4-2Table 4-2
从实施例16至19的测试结果可以看出，在保持氮掺杂多孔碳孔体积、壁厚和其他条件不变的前提下，提高氮掺杂多孔碳孔径，多孔碳的比表面积会降低，孔径的适当增大，有利于为硅膨胀预留出更加充分的空间，以获得更加稳定的结构，进而表现出较好的循环性能，但是孔径过大时，在孔体积、孔壁厚和硅含量不变的前提下，含硅材料层的厚度也会相应的增加，更大的膨胀应力会破环孔结构，造成结构坍塌，进而引起整体颗粒的破碎，引起循环性能的恶化。实施例19则证明了将孔大小提高到30nm时，电池表现出了较差的电化学性能。From the test results of Examples 16 to 19, it can be seen that under the premise of keeping the pore volume, wall thickness and other conditions of nitrogen-doped porous carbon unchanged, increasing the pore size of nitrogen-doped porous carbon will reduce the specific surface area of porous carbon. Appropriate increase in the pore size is conducive to reserving more sufficient space for silicon expansion to obtain a more stable structure, thereby showing better cycle performance, but when the pore size is too large, the pore volume, pore wall thickness and silicon content will not Under the premise of changing, the thickness of the silicon-containing material layer will also increase accordingly, and the larger expansion stress will destroy the annular pore structure, causing the structure to collapse, and then cause the fragmentation of the whole particle, resulting in the deterioration of the cycle performance. Example 19 demonstrates that when the pore size is increased to 30 nm, the cell exhibits poor electrochemical performance.
从实施例17、20、21和22的测试结果可以看出，在保持孔尺寸和其他条件不变的前提下，提高孔体积，会增加比表面积，因碳含量不变，相应的多孔碳壁厚会提高，更大的孔体积，意味着沉积在孔表面的含硅材料层厚度更小，在嵌锂反应中造成的膨胀应力也更小，且多孔碳壁厚的提高对缓冲膨胀应力更有利，然而进一步提高孔体积，增加孔的数量，会降低整体结构的稳定性，实施例22则直接说明了当孔体积提高15cm
2/g后，负极材料在嵌锂后结构坍塌，电池表现出了快速的容量衰减和膨胀增加。
From the test results of Examples 17, 20, 21 and 22, it can be seen that under the premise of keeping the pore size and other conditions unchanged, increasing the pore volume will increase the specific surface area. The thickness will increase, and the larger pore volume means that the thickness of the silicon-containing material layer deposited on the pore surface is smaller, and the expansion stress caused by the lithium intercalation reaction is also smaller, and the increase of the porous carbon wall thickness will buffer the expansion stress. However, further increasing the pore volume and increasing the number of pores will reduce the stability of the overall structure. Example 22 directly shows that when the pore volume is increased by 15 cm 2 /g, the structure of the negative electrode material collapses after lithium intercalation, and the battery shows Rapid capacity decay and swelling increase.
从实施例17、23、24和25的测试结果可以看出，在保持孔大小和其他条件不变的情况下，增加多孔碳壁厚，因碳含量不变，相应的孔体积和比表面积会降低，在壁厚增加初期是有益的，可以增加对硅膨胀应力的缓冲，但继续增加壁厚，会降低孔体积，在相同硅含量下，硅沉积厚度会增加，含硅材料层厚度的增加带来膨胀应力增加对电化学性能会占主导地位，实施例25则直接说明了当壁厚增加到40nm时，壁厚对膨胀的缓冲效果不足以支撑膨胀应力的大幅增加，电池表现出来较差的电化学性能。From the test results of Examples 17, 23, 24 and 25, it can be seen that, while keeping the pore size and other conditions unchanged, increasing the porous carbon wall thickness, due to the constant carbon content, the corresponding pore volume and specific surface area will be Decrease is beneficial in the early stage of wall thickness increase, which can increase the buffering of silicon expansion stress, but continue to increase the wall thickness, it will reduce the pore volume, under the same silicon content, the silicon deposition thickness will increase, and the thickness of the silicon-containing material layer will increase. The increase in expansion stress will dominate the electrochemical performance. Example 25 directly shows that when the wall thickness increases to 40 nm, the buffering effect of the wall thickness on expansion is not enough to support the large increase in expansion stress, and the battery shows poor performance. electrochemical performance.
根据上述方法制得的实施例26至32的负极材料，其制得的锂电池的性能测试结 果见表所示。The negative electrode materials of Examples 26 to 32 prepared according to the above method, the performance test results of the prepared lithium batteries are shown in the table.
表5table 5
从实施例26至30的测试结果可以看出，在极片OI值和其他条件不变的前提下，当增加所述硅碳负极材料的孔隙率时，如实施例28所示，当增加孔隙率到33％时，复合物具有较好的膨胀空间，有利于改善膨胀性能，但较多的孔隙恶化了电接触，不利于倍率性能，而当降低孔隙率到22％时，如实施例26所示，此时孔隙率较低不利于缓冲硅锂化中产生的膨胀应力，在循环中造成较差的膨胀性能；实施例29、30分别降低孔隙率到10％和增加到50％时，分别极大的恶化了材料的膨胀性能和倍率性能。From the test results of Examples 26 to 30, it can be seen that under the premise that the OI value of the pole piece and other conditions remain unchanged, when the porosity of the silicon carbon anode material is increased, as shown in Example 28, when the porosity is increased When the ratio reaches 33%, the composite has better expansion space, which is beneficial to improve the expansion performance, but more pores deteriorate the electrical contact, which is not conducive to the rate performance, and when the porosity is reduced to 22%, as in Example 26 As shown, the lower porosity at this time is not conducive to buffering the expansion stress generated in the lithiation of silicon, resulting in poor expansion performance during cycling; in Examples 29 and 30, when the porosity was reduced to 10% and increased to 50%, respectively, The expansion performance and rate performance of the material are greatly deteriorated, respectively.
从实施例27、31至32的测试结果可以看出，在保持极片孔隙率和其他条件不变的前提下，提高极片OI值，有利于改善锂离子传输速率，改善电池的倍率性能。From the test results of Examples 27, 31 to 32, it can be seen that under the premise of keeping the porosity of the pole piece and other conditions unchanged, increasing the OI value of the pole piece is beneficial to improve the lithium ion transmission rate and improve the rate performance of the battery.
本申请虽然以较佳实施例公开如上，但并不是用来限定权利要求，任何本领域技术人员在不脱离本申请构思的前提下，都可以做出若干可能的变动和修改，因此本申请的保护范围应当以本申请权利要求所界定的范围为准。Although the present application is disclosed above with preferred embodiments, it is not used to limit the claims. Any person skilled in the art can make some possible changes and modifications without departing from the concept of the present application. The scope of protection shall be subject to the scope defined by the claims of this application.
Claims (14)
- 一种负极材料，其特征在于，所述负极材料包括活性材料及位于所述活性材料表面的碳层，所述活性材料包括氮掺杂多孔碳及含硅材料层；所述负极材料中的硅的质量百分比含量为30％至80％。A negative electrode material, characterized in that the negative electrode material comprises an active material and a carbon layer on the surface of the active material, the active material comprises nitrogen-doped porous carbon and a silicon-containing material layer; The mass percentage content of 30% to 80%.
- 根据权利要求1所述的负极材料，其特征在于，所述含硅材料层位于所述氮掺杂多孔碳的孔壁。The negative electrode material according to claim 1, wherein the silicon-containing material layer is located on the pore walls of the nitrogen-doped porous carbon.
- 根据权利要求1或2所述的负极材料，其特征在于，所述负极材料满足以下条件(1)至(4)中的至少一者：The negative electrode material according to claim 1 or 2, wherein the negative electrode material satisfies at least one of the following conditions (1) to (4):(1)所述含硅材料层的厚度D 0的取值范围为1nm至10nm； (1) The thickness D 0 of the silicon-containing material layer ranges from 1 nm to 10 nm;(2)所述含硅材料层的厚度D 0与所述氮掺杂多孔碳的孔径D 1的比值范围满足：0.2≤D 0/D 1<0.8； (2) The ratio range of the thickness D 0 of the silicon-containing material layer to the pore diameter D 1 of the nitrogen-doped porous carbon satisfies: 0.2≦D 0 /D 1 <0.8;(3)所述含硅材料层的厚度D 0与所述碳层的厚度D 2的比值范围满足：0.05≤D 0/D 2≤10； (3) The ratio range of the thickness D 0 of the silicon-containing material layer to the thickness D 2 of the carbon layer satisfies: 0.05≦D 0 /D 2 ≦10;(4)所述氮掺杂多孔碳中的多孔碳的壁厚为5nm至30nm。(4) The porous carbon in the nitrogen-doped porous carbon has a wall thickness of 5 nm to 30 nm.
- 根据权利要求1所述的负极材料，其特征在于，所述氮掺杂多孔碳满足以下条件(1)至(3)中的至少一者：The negative electrode material according to claim 1, wherein the nitrogen-doped porous carbon satisfies at least one of the following conditions (1) to (3):(1)所述氮掺杂多孔碳的比表面积为2000m 2/g至3500m 2/g； (1) the nitrogen-doped porous carbon has a specific surface area of 2000 m 2 /g to 3500 m 2 /g;(2)所述氮掺杂多孔碳的孔体积为1cm 2/g至10cm 2/g； (2) the nitrogen-doped porous carbon has a pore volume of 1 cm 2 /g to 10 cm 2 /g;(3)所述氮掺杂多孔碳中的孔的平均孔径为1nm至20nm。(3) The average pore diameter of the pores in the nitrogen-doped porous carbon is 1 nm to 20 nm.
- 根据权利要求1所述的负极材料，其特征在于，所述负极材料满足以下条件(1)至(7)中的至少一者：The negative electrode material according to claim 1, wherein the negative electrode material satisfies at least one of the following conditions (1) to (7):(1)所述负极材料的比表面积为1m 2/g至50m 2/g； (1) The specific surface area of the negative electrode material is 1 m 2 /g to 50 m 2 /g;(2)所述负极材料的孔体积为0.001cm 2/g至0.1cm 2/g； (2) the pore volume of the negative electrode material is 0.001 cm 2 /g to 0.1 cm 2 /g;(3)所述负极材料的粒径范围为1um至100um，和/或，所述负极材料的平均粒径为2.5um至50um；(3) The particle size of the negative electrode material ranges from 1um to 100um, and/or the average particle size of the negative electrode material is 2.5um to 50um;(4)所述负极材料的粉末电导率为2.0S/cm至30S/cm；(4) The powder conductivity of the negative electrode material is 2.0S/cm to 30S/cm;(5)所述负极材料的碳层的厚度为2nm至20nm；(5) the thickness of the carbon layer of the negative electrode material is 2 nm to 20 nm;(6)所述负极材料中的碳层的质量百分比含量为3％至10％；(6) The mass percentage content of the carbon layer in the negative electrode material is 3% to 10%;(7)所述负极材料中的氮掺杂多孔碳的质量百分比含量为10％至67％。(7) The mass percentage content of nitrogen-doped porous carbon in the negative electrode material is 10% to 67%.
- 根据权利要求1所述的负极材料，其特征在于，通过拉曼光谱法，所述负极材料在1350cm -1处的峰强度I D与在1580cm -1处的峰强度I G的比值I D/I G的取值范围为1.2至2.2。 The negative electrode material according to claim 1, characterized in that, by Raman spectroscopy, the ratio of the peak intensity ID at 1350 cm- 1 to the peak intensity IG at 1580 cm -1 of the negative electrode material, ID / The value of IG ranges from 1.2 to 2.2.
- 根据权利要求1所述的负极材料，其特征在于，所述氮掺杂多孔碳满足以下条件(1)至(3)中的至少一者：The negative electrode material according to claim 1, wherein the nitrogen-doped porous carbon satisfies at least one of the following conditions (1) to (3):(1)所述氮掺杂多孔碳中的氮元素以C-N键形式掺杂在碳体相中；(1) The nitrogen element in the nitrogen-doped porous carbon is doped in the carbon bulk phase in the form of C-N bonds;(2)所述氮掺杂多孔碳中的氮的质量百分比含量为0.5％至10％；(2) the mass percentage content of nitrogen in the nitrogen-doped porous carbon is 0.5% to 10%;(3)通过XPS分析，所述氮掺杂多孔碳中的氮的构型包括吡啶类氮、吡咯类氮、石墨类氮、石墨化氮和氧化类氮中的至少一种，且所述石墨化氮在所有氮中的质量占 比为30％至70％。(3) Through XPS analysis, the configuration of nitrogen in the nitrogen-doped porous carbon includes at least one of pyridine-based nitrogen, pyrrole-based nitrogen, graphitic nitrogen, graphitized nitrogen, and oxide-based nitrogen, and the graphite Nitrogen makes up 30% to 70% of all nitrogen by mass.
- 一种如权利要求1～7任一项所述的负极材料的制备方法，其特征在于，所述方法包括以下步骤：A method for preparing a negative electrode material according to any one of claims 1 to 7, wherein the method comprises the following steps:将抗生素菌渣经金属盐高温碳化处理及酸洗处理，得到氮掺杂多孔碳；The antibiotic bacterial residue is subjected to high-temperature carbonization treatment and pickling treatment of metal salts to obtain nitrogen-doped porous carbon;利用硅烷气体对所述氮掺杂多孔碳进行气相沉积，得到活性材料；Using silane gas to vapor-deposit the nitrogen-doped porous carbon to obtain an active material;将所述活性材料与碳源混合后进行碳复合处理，得到负极材料。The active material is mixed with a carbon source and then carbon composite treatment is performed to obtain a negative electrode material.
- 根据权利要求8所述的制备方法，其特征在于，所述方法满足以下条件(1)至(3)中的至少一者：The preparation method according to claim 8, wherein the method satisfies at least one of the following conditions (1) to (3):(1)所述碳源包括树脂、沥青、高分子聚合物中的至少一种；(1) The carbon source includes at least one of resin, pitch, and high molecular polymer;(2)所述金属盐包括氯化钠、氯化钾、碳酸钠或碳酸钾中的至少一种；(2) described metal salt includes at least one in sodium chloride, potassium chloride, sodium carbonate or potassium carbonate;(3)所述酸洗处理所采用的酸包括盐酸、硫酸、硝酸、草酸、氢氟酸或磷酸中的至少一种。(3) The acid used in the pickling treatment includes at least one of hydrochloric acid, sulfuric acid, nitric acid, oxalic acid, hydrofluoric acid or phosphoric acid.
- 一种负极极片，包括负极集流体以及设置于所述负极集流体表面的负极活性材料层，其特征在于，所述负极活性材料层包括权利要求1至7中任一项所述的负极材料或权利要求8至9中任一项所述的制备方法制得的负极材料。A negative electrode pole piece, comprising a negative electrode current collector and a negative electrode active material layer disposed on the surface of the negative electrode current collector, wherein the negative electrode active material layer comprises the negative electrode material described in any one of claims 1 to 7 or the negative electrode material prepared by the preparation method according to any one of claims 8 to 9.
- 根据权利要求10所述的负极极片，其特征在于，所述负极极片满足以下条件(1)至(4)中的至少一者：The negative pole piece according to claim 10, wherein the negative pole piece satisfies at least one of the following conditions (1) to (4):(1)所述负极活性材料层的孔隙率为20％至40％；(1) The porosity of the negative electrode active material layer is 20% to 40%;(2)所述负极活性材料层的电阻的取值范围为0.2Ω至2Ω；(2) the value range of the resistance of the negative electrode active material layer is 0.2Ω to 2Ω;(3)在5T压力下，所述负极活性材料层的压实密度为1.5g/cm 3至2.0g/cm 3； (3) Under a pressure of 5T, the compaction density of the negative electrode active material layer is 1.5g/cm 3 to 2.0g/cm 3 ;(4)所述负极活性材料层的OI值的取值范围为1至20。(4) The value range of the OI value of the negative electrode active material layer is 1 to 20.
- 一种电化学装置，包括负极活性材料层，其特征在于，所述负极活性材料层包括权利要求1至7中任一项所述的负极材料或权利要求8至9中任一项所述的制备方法制得的负极材料。An electrochemical device comprising a negative electrode active material layer, wherein the negative electrode active material layer comprises the negative electrode material described in any one of claims 1 to 7 or the negative electrode material described in any one of claims 8 to 9 The negative electrode material prepared by the preparation method.
- 根据权利要求12所述的电化学装置，其特征在于，所述电化学装置为锂离子电池。The electrochemical device of claim 12, wherein the electrochemical device is a lithium-ion battery.
- 一种电子装置，其特征在于，所述电子装置包括权利要求12所述的电化学装置。An electronic device, characterized in that, the electronic device comprises the electrochemical device of claim 12 .
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116014141A (en) * | 2023-02-10 | 2023-04-25 | 江苏正力新能电池技术有限公司 | Porous silicon negative electrode material, silicon negative electrode sheet and lithium ion battery |
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| Publication number | Publication date |
|---|---|
| CN114051663A (en) | 2022-02-15 |
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