WO2024098352A1 - 负极活性材料及其制备方法、二次电池及其制备方法、用电装置 - Google Patents

负极活性材料及其制备方法、二次电池及其制备方法、用电装置 Download PDF

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WO2024098352A1
WO2024098352A1 PCT/CN2022/131246 CN2022131246W WO2024098352A1 WO 2024098352 A1 WO2024098352 A1 WO 2024098352A1 CN 2022131246 W CN2022131246 W CN 2022131246W WO 2024098352 A1 WO2024098352 A1 WO 2024098352A1
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negative electrode
electrode active
active material
silicon
carbon
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PCT/CN2022/131246
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English (en)
French (fr)
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邓亚茜
陈宁
吕瑞景
程志鹏
史东洋
金海族
李白清
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宁德时代新能源科技股份有限公司
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Priority to PCT/CN2022/131246 priority Critical patent/WO2024098352A1/zh
Publication of WO2024098352A1 publication Critical patent/WO2024098352A1/zh

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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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • 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
    • H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
    • 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 field of secondary batteries, and more specifically to negative electrode active materials and preparation methods thereof, secondary batteries and preparation methods thereof, and electrical devices.
  • silicon-based materials with high specific capacity can be used to replace graphite to increase the energy density of the battery.
  • the volume expansion of silicon-based materials after charging is much greater than that of graphite, and their own polarization is large, which will deteriorate the dynamics of the anode. Therefore, in order to obtain an anode with more balanced performance, it is often necessary to compound silicon-based materials and carbon-based materials into mixed anode materials.
  • silicon-based materials and carbon-based materials are often treated by simple physical mixing.
  • This treatment method is difficult to avoid the agglomeration of particles of the same type, such as the agglomeration of silicon-based material particles or the agglomeration of carbon-based material particles.
  • the agglomeration of silicon particles is more likely to lead to large local lithium concentration differences in the anode, which in turn leads to safety issues such as excessive cell expansion force, poor kinetics and lithium precipitation.
  • the most direct manifestation is the decline in battery rate performance.
  • a negative electrode active material including a carbon-based material and a silicon-based material, wherein a first functional group exists on the surface of the carbon-based material, and a second functional group exists on the surface of the silicon-based material, and the first functional group carries a charge opposite to that of the second functional group.
  • the present application modifies the surfaces of carbon-based materials and silicon-based materials with functional groups with opposite charges, so that particles of the same type of materials repel each other due to the same charges, thereby avoiding agglomeration of particles of the same type.
  • Particles of different types of materials carry opposite charges and have a certain electrostatic effect, so that different types of active materials can be evenly distributed in the entire system, effectively avoiding problems in traditional technologies such as decreased rate performance due to uneven particle distribution, uneven thickness due to local expansion of the battery cell, and lithium precipitation.
  • the charge carried by the first functional group is positive, and the charge carried by the second functional group is negative.
  • the agglomeration between silicon and the conductive agent can be effectively avoided, thereby further improving the dispersion performance of the entire system and enhancing the battery rate performance.
  • the silicon-negative and carbon-positive solution will have a more obvious advantage.
  • the first functional group includes one or more of an amino group, an amide group, a cyano group, and a boronic acid group.
  • the second functional group includes one or more of a carboxyl group, a sulfonic acid group, a hydroxyl group, and a halogen group.
  • the appropriate type of functional group can not only prevent particle agglomeration and improve the dispersibility of the system, but also will not adversely affect other properties of the battery.
  • the mass percentage of the silicon-based material in the negative electrode active material is 1% to 99%; alternatively, the mass percentage of the silicon-based material in the negative electrode active material is 25% to 85%.
  • the mass percentage of the carbon-based material in the negative electrode active material is 1% to 99%; alternatively, the mass percentage of the carbon-based material in the negative electrode active material is 15% to 75%.
  • Controlling the proportion of silicon-based materials and carbon-based materials in the negative electrode active materials within an appropriate range can balance the contradiction between the battery's capacity and rate performance, thereby maximizing the battery's overall performance; at the same time, it can also make the overall electrical properties of the negative electrode active materials appropriate, thereby further improving the dispersion stability of the slurry when preparing the negative electrode slurry.
  • the carbon-based material includes small-sized particles and large-sized particles, the D50 particle size of the small-sized particles is 0.2 ⁇ m to 9.99 ⁇ m, and the D50 particle size of the large-sized particles is 10 ⁇ m to 100 ⁇ m.
  • Carbon-based materials are compounded with large-sized particles and small-sized particles within a certain particle size range, which can effectively reduce material defects and increase battery capacity without causing excessive deterioration of battery kinetic performance.
  • the mass percentage of the small-sized particles in the negative electrode active material is 1% to 99%, and the mass percentage of the large-sized particles in the negative electrode active material is 1% to 99%; alternatively, the mass percentage of the small-sized particles in the negative electrode active material is 5% to 75%, and the mass percentage of the large-sized particles in the negative electrode active material is 25% to 95%. Controlling the proportion of large-sized particles and small-sized particles within a suitable range can make the compounding effect of the two better and further improve the rate performance of the battery.
  • the D50 particle size of the silicon-based material is 0.2 ⁇ m to 100 ⁇ m; alternatively, the D50 particle size of the silicon-based material is 0.2 ⁇ m to 30 ⁇ m. Controlling the particle size of the silicon-based material within a suitable range can balance the battery capacity and kinetic performance, so that the battery has better overall performance.
  • the negative electrode active material satisfies at least one of the following conditions (1) to (2):
  • the concentration of the stable aqueous dispersion of the carbon-based material is 0.1 mg/mL to 100 mg/mL;
  • the concentration of the stable aqueous dispersion of the silicon-based material is 0.1 mg/mL to 100 mg/mL;
  • the stable aqueous dispersion refers to a liquid phase obtained by solid-liquid separation of a dispersion that uses water as a solvent and does not precipitate after being allowed to stand for more than 2 hours after preparation.
  • the material Only by controlling the concentration of the material's stable aqueous dispersion within an appropriate range can the material be charged with an appropriate amount of charge, thereby helping to further improve the dispersion stability of the system.
  • a method for preparing the negative electrode active material according to one or more of the above embodiments comprising the following steps:
  • the carbon-based raw material, the first surfactant and the solvent are mixed to prepare a first dispersion, and after standing for more than 2 hours, solid-liquid separation is performed to retain the liquid phase to obtain a first stable dispersion; the first stable dispersion is centrifuged to obtain a first precipitate; the first precipitate is washed and dried to obtain the carbon-based material;
  • the silicon-based raw material, the second surfactant and the solvent are mixed to prepare a second dispersion, and the mixture is allowed to stand for more than 2 hours to perform solid-liquid separation, and the liquid phase is retained to obtain a second stable dispersion; the second stable dispersion is subjected to centrifugal separation to obtain a second precipitate; the second precipitate is washed and dried to obtain the silicon-based material;
  • the first surfactant and the second surfactant carry opposite charges in the solvent.
  • the appropriate preparation method can make the raw materials evenly charged with a moderate amount of charge, further improving the dispersion performance of the negative electrode active material and reducing agglomeration.
  • the preparation method satisfies one or more of the following conditions (1) to (5):
  • the carbon-based raw material includes one or more of artificial graphite, natural graphite, soft carbon and hard carbon;
  • the silicon-based raw material includes one or more of Si and SiO x (0 ⁇ x ⁇ 2);
  • the first surfactant and the second surfactant are independently selected from one or more of the following: dodecylamine, hexadecylamide, dodecanitrile, ethoxyboric acid diglyceride, sodium cholate, sodium dodecylbenzenesulfonate, decynediol and hexadecyl bromide; the appropriate type of surfactant can make the surface of the raw material carry the appropriate type of functional group, provide charge, improve the dispersion performance of the material, and will not cause damage to other battery performance;
  • the amount of the first surfactant is 0.1% to 40% of the mass of the carbon-based raw material; the appropriate amount of surfactant can make the surface of the obtained carbon-based material evenly carry an appropriate amount of charge;
  • the dosage of the second surfactant is 0.1% to 40% of the mass of the silicon-based raw material.
  • the appropriate dosage of the surfactant can make the surface of the obtained silicon-based material evenly carry an appropriate amount of charge.
  • a secondary battery comprising a positive electrode sheet, a negative electrode sheet and a separator, wherein the separator is disposed between the positive electrode sheet and the negative electrode sheet;
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector, and the negative electrode active material layer includes the negative electrode active material described in one of the aforementioned multiple embodiments.
  • a method for preparing a secondary battery comprising the following steps:
  • the positive electrode sheet, the separator and the negative electrode sheet are stacked or wound to prepare the secondary battery.
  • an electrical device comprising the aforementioned secondary battery or a secondary battery manufactured by the aforementioned manufacturing method.
  • FIG. 1 is a schematic diagram of a secondary battery according to an embodiment of the present application.
  • FIG. 2 is an exploded view of the secondary battery according to the embodiment of the present application shown in FIG. 1 .
  • FIG. 3 is a schematic diagram of an electric device using a secondary battery as a power source according to an embodiment of the present application.
  • “Scope” disclosed in the present application is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range.
  • the scope limited in this way can include or exclude end values, and can be arbitrarily combined, that is, any lower limit can form a scope with any upper limit combination. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected.
  • the minimum range values 1 and 2 listed, and if the maximum range values 3,4 and 5 are listed, the following scope can be fully expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5.
  • the numerical range "a-b” represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers.
  • the numerical range "0-5" represents that all real numbers between "0-5" have been fully listed herein, and "0-5" is just the abbreviation of these numerical combinations.
  • a parameter is expressed as an integer ⁇ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.
  • the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially.
  • the method may further include step (c), which means that step (c) may be added to the method in any order.
  • the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.
  • the “include” and “comprising” mentioned in this application represent open-ended or closed-ended expressions.
  • the “include” and “comprising” may represent that other components not listed may also be included or only the listed components may be included or only the listed components may be included.
  • the term "or” is inclusive.
  • the phrase “A or B” means “A, B, or both A and B”. More specifically, any of the following conditions satisfies the condition "A or B”: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).
  • Silicon-based materials have been gradually used as negative electrode active materials due to their high theoretical specific capacity and lower risk of lithium plating, in order to meet the market's growing demand for high-capacity secondary batteries.
  • silicon-based materials due to their high expansion coefficient and large polarization, silicon-based materials usually need to be mixed with carbon-based materials such as graphite to balance the contradiction between specific capacity and expansion coefficient and improve the overall performance of the battery.
  • carbon-based materials such as graphite
  • Agglomeration will have a significant negative impact on the performance of the battery, and it is easy to cause problems such as local over-expansion and reduced rate performance.
  • the first aspect of the present application provides a negative electrode active material, including a carbon-based material and a silicon-based material, wherein a first functional group exists on the surface of the carbon-based material, and a second functional group exists on the surface of the silicon-based material, and the first functional group carries a charge opposite to that of the second functional group.
  • the present application modifies the surfaces of carbon-based materials and silicon-based materials with functional groups with opposite charges, so that particles of the same type of materials repel each other due to the same charges, thereby avoiding agglomeration of particles of the same type.
  • Particles of different types of materials carry opposite charges and have a certain electrostatic effect, so that different types of active materials can be evenly distributed in the entire system, effectively avoiding problems such as decreased rate performance, excessive expansion, lithium precipitation, etc. caused by uneven particle distribution in traditional technologies.
  • the charge carried by the first functional group is positive, and the charge carried by the second functional group is negative.
  • the negative impact on the performance of the battery is more serious after silicon agglomeration than after carbon agglomeration, when silicon is negatively charged and carbon is positively charged, the agglomeration between silicon and the conductive agent can be effectively avoided, thereby further improving the dispersion performance of the entire system and enhancing the battery rate performance.
  • the silicon-negative and carbon-positive solution will have more obvious advantages.
  • the first functional group includes one or more of an amino group, an amide group, a cyano group, and a boronic acid group.
  • the second functional group includes one or more of a carboxyl group, a sulfonic acid group, a hydroxyl group, and a halogen group.
  • the appropriate type of functional group can not only prevent particle agglomeration and improve the dispersibility of the system, but also will not adversely affect other properties of the battery. It can be understood that the existence of the functional group is to enable the negative electrode material particles to be charged. Therefore, the specific substituents present on the surface of the material are not limited, as long as they contain the above functional groups and can be charged normally.
  • the amino group can be just a single amino group, or it can be an amino group present in -CH2NH2 , or it can be an amino group present in -COOCH2NH2 ;
  • the carboxyl group can be a single carboxyl group or -CH2COOH ;
  • the halogen group can be a single fluorine atom or a perfluoroalkyl group.
  • the halogen group includes one or more of -F, -Cl and -Br.
  • the mass percentage of silicon-based materials in the negative electrode active material is 1% to 99%; optionally, the mass percentage of silicon-based materials in the negative electrode active material can be, for example, 25% to 85%, and can also be 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or 95%.
  • the mass percentage of the carbon-based material in the negative electrode active material is 1% to 99%; optionally, the mass percentage of the carbon-based material in the negative electrode active material can be, for example, 15% to 75%, and can also be 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or 95%.
  • Controlling the proportion of silicon-based materials and carbon-based materials in the negative electrode active materials within an appropriate range can balance the contradiction between the battery's capacity and rate performance, thereby maximizing the battery's overall performance; at the same time, it can also make the overall electrical properties of the negative electrode active materials appropriate, thereby further improving the dispersion stability of the slurry when preparing the negative electrode slurry.
  • the carbon-based material includes small-sized particles and large-sized particles
  • the D50 particle size of the small-sized particles is 0.2 ⁇ m to 9.9 ⁇ m
  • the D50 particle size of the large-sized particles is 10 ⁇ m to 100 ⁇ m.
  • the D50 particle size of the small-sized particles can also be, for example, 0.5 ⁇ m, 1 ⁇ m, 1.5 ⁇ m, 2 ⁇ m, 2.5 ⁇ m, 3 ⁇ m, 3.5 ⁇ m, 4 ⁇ m, 4.5 ⁇ m, 5 ⁇ m, 5.5 ⁇ m, 6 ⁇ m, 6.5 ⁇ m, 7 ⁇ m, 7.5 ⁇ m, 8 ⁇ m, 8.5 ⁇ m, 9 ⁇ m or 9.5 ⁇ m.
  • the D50 particle size of the large-sized particles can also be, for example, 15 ⁇ m, 20 ⁇ m, 25 ⁇ m, 30 ⁇ m, 35 ⁇ m, 40 ⁇ m, 45 ⁇ m, 50 ⁇ m, 55 ⁇ m, 60 ⁇ m, 65 ⁇ m, 70 ⁇ m, 75 ⁇ m, 80 ⁇ m, 85 ⁇ m, 90 ⁇ m or 95 ⁇ m.
  • Carbon-based materials are compounded with large-sized particles and small-sized particles within a certain particle size range, which can effectively reduce material defects and increase battery capacity without causing excessive deterioration of battery kinetic performance.
  • D50 refers to the particle size corresponding to the cumulative distribution number of particles reaching 50% in the particle size cumulative distribution curve. Its physical meaning is that the number of particles with a particle size smaller than (or larger than) this particle size value accounts for 50% respectively.
  • D50 can be conveniently measured by a laser particle size analyzer with reference to GB/T 19077-2016 particle size distribution laser diffraction method, such as the Mastersizer 2000E laser particle size analyzer of Malvern Instruments Ltd., UK.
  • the mass percentage of small-sized particles in the negative electrode active material is 1% to 99%, and the mass percentage of large-sized particles in the negative electrode active material is 1% to 99%; alternatively, the mass percentage of small-sized particles in the negative electrode active material is 5% to 75%, and the mass percentage of large-sized particles in the negative electrode active material is 25% to 95%.
  • the mass percentage of small-sized particles in the negative electrode active material can also be, for example, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or 95%.
  • the mass percentage of large-sized particles in the negative electrode active material can also be, for example, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or 95%. Controlling the proportion of large-sized particles and small-sized particles within a suitable range can make the compounding effect of the two better and further improve the rate performance of the battery.
  • the D50 particle size of the silicon-based material is 0.2 ⁇ m to 100 ⁇ m; optionally, the D50 particle size of the silicon-based material is 0.2 ⁇ m to 30 ⁇ m, and the D50 particle size of the silicon-based material can also be 5 ⁇ m, 10 ⁇ m, 15 ⁇ m, 20 ⁇ m, 25 ⁇ m, 30 ⁇ m, 35 ⁇ m, 40 ⁇ m, 45 ⁇ m, 50 ⁇ m, 55 ⁇ m, 60 ⁇ m, 65 ⁇ m, 70 ⁇ m, 75 ⁇ m, 80 ⁇ m, 85 ⁇ m, 90 ⁇ m or 95 ⁇ m. Controlling the particle size of the silicon-based material within a suitable range can balance the battery capacity and kinetic performance, so that the battery has better comprehensive performance.
  • the negative electrode active material satisfies at least one of the following conditions (1) to (2):
  • the concentration of the stable aqueous dispersion of the carbon-based material is 0.1 mg/mL to 100 mg/mL; the concentration of the stable aqueous dispersion of the carbon-based material may also be, for example, 10 mg/mL, 20 mg/mL, 30 mg/mL, 40 mg/mL, 50 mg/mL, 60 mg/mL, 70 mg/mL, 80 mg/mL or 90 mg/mL;
  • the concentration of the stable aqueous dispersion of the silicon-based material is 0.1 mg/mL to 100 mg/mL; the concentration of the stable aqueous dispersion of the silicon-based material may also be, for example, 10 mg/mL, 20 mg/mL, 30 mg/mL, 40 mg/mL, 50 mg/mL, 60 mg/mL, 70 mg/mL, 80 mg/mL or 90 mg/mL;
  • the stable aqueous dispersion refers to a liquid phase obtained after solid-liquid separation of a dispersion that uses water as a solvent and does not precipitate after being allowed to stand for more than 2 hours after preparation.
  • the material Only by controlling the concentration of the material's stable aqueous dispersion within an appropriate range can the material be charged with an appropriate amount of charge, thereby helping to further improve the dispersion stability of the system.
  • a method for preparing a negative electrode active material according to one or more of the above embodiments comprising the following steps:
  • the carbon-based raw material, the first surfactant and the solvent are mixed to prepare a first dispersion, and after standing for more than 2 hours, solid-liquid separation is performed to retain the liquid phase to obtain a first stable dispersion; the first stable dispersion is centrifuged to obtain a first precipitate; the first precipitate is washed and dried to obtain a carbon-based material;
  • the silicon-based raw material, the second surfactant and the solvent are mixed to prepare a second dispersion, and after standing for more than 2 hours, solid-liquid separation is performed to retain the liquid phase to obtain a second stable dispersion; the second stable dispersion is centrifuged to obtain a second precipitate; the second precipitate is washed and dried to obtain a silicon-based material;
  • the first surfactant and the second surfactant carry opposite charges in the solvent.
  • the appropriate preparation method can make the raw materials evenly charged with a moderate amount of charge, further improving the dispersion performance of the negative electrode active material and reducing agglomeration.
  • the preparation method satisfies one or more of the following conditions (1) to (5):
  • the carbon-based raw material includes one or more of artificial graphite, natural graphite, soft carbon and hard carbon;
  • the silicon-based raw material includes one or more of Si and SiO x (0 ⁇ x ⁇ 2);
  • the first surfactant and the second surfactant are independently selected from one or more of the following: dodecylamine, hexadecylamide, dodecanitrile, ethoxyboric acid diglyceride, sodium cholate, sodium dodecylbenzenesulfonate, decynediol and hexadecyl bromide; the appropriate type of surfactant can make the surface of the raw material carry the appropriate type of functional group, provide charge, improve the dispersion performance of the material without causing damage to other battery performance, but the available surfactants are not limited to the types listed above, which are only representatives of some easily available and effective surfactants;
  • the amount of the first surfactant is 0.1% to 40% of the mass of the carbon-based raw material; the amount of the first surfactant can also be, for example, 5%, 10%, 15%, 20%, 25%, 30% or 35% of the mass of the carbon-based raw material.
  • the appropriate amount of surfactant can make the surface of the obtained carbon-based material evenly carry an appropriate amount of charge;
  • the amount of the second surfactant is 0.1% to 40% of the mass of the silicon-based raw material; the amount of the second surfactant can also be, for example, 5%, 10%, 15%, 20%, 25%, 30% or 35% of the mass of the silicon-based raw material.
  • the appropriate amount of surfactant can make the surface of the obtained silicon-based material uniformly carry an appropriate amount of charge.
  • a secondary battery comprising a positive electrode sheet, a negative electrode sheet and a separator, wherein the separator is disposed between the positive electrode sheet and the negative electrode sheet;
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector, and the negative electrode active material layer includes the negative electrode active material of one of the aforementioned multiple embodiments.
  • a method for preparing a secondary battery comprising the following steps:
  • a negative electrode current collector is provided, and a negative electrode slurry is coated on the surface of the negative electrode current collector, and the negative electrode slurry is dried and pressed to obtain a negative electrode sheet; wherein the negative electrode slurry includes one or more negative electrode active materials of the aforementioned embodiments; optionally, the solid content of the negative electrode slurry is 30% to 70%; the solid content of the negative electrode slurry can also be 35%, 40%, 45%, 50%, 55%, 60% or 65%.
  • the appropriate slurry solid content can better match the technical solution of the present application, further improve the dispersion stability of various particles in the negative electrode active material, and avoid agglomeration;
  • the positive electrode sheet, the separator and the negative electrode sheet are stacked or wound to prepare a secondary battery.
  • an electrical device comprising the aforementioned secondary battery or a secondary battery manufactured by the aforementioned manufacturing method.
  • a secondary battery is provided.
  • a secondary battery includes a positive electrode sheet, a negative electrode sheet, an electrolyte and a separator.
  • active ions are embedded and released back and forth between the positive electrode sheet and the negative electrode sheet.
  • the electrolyte plays the role of conducting ions between the positive electrode sheet and the negative electrode sheet.
  • the separator is set between the positive electrode sheet and the negative electrode sheet, mainly to prevent the positive and negative electrodes from short-circuiting, while allowing ions to pass through.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector, wherein the positive electrode film layer includes a positive electrode active material.
  • the positive electrode current collector has two surfaces opposite to each other in its thickness direction, and the positive electrode film layer is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.
  • the positive electrode current collector may be a metal foil or a composite current collector.
  • the metal foil aluminum foil may be used.
  • the composite current collector may include a polymer material base and a metal layer formed on at least one surface of the polymer material base.
  • the composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
  • PP polypropylene
  • PET polyethylene terephthalate
  • PBT polybutylene terephthalate
  • PS polystyrene
  • PE polyethylene
  • the positive electrode active material may be a positive electrode active material for a battery known in the art.
  • the positive electrode active material may include at least one of the following materials: an olivine-structured lithium-containing phosphate, a lithium transition metal oxide, and their respective modified compounds.
  • the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more.
  • lithium transition metal oxides may include, but are not limited to , lithium cobalt oxide (such as LiCoO2 ), lithium nickel oxide (such as LiNiO2 ), lithium manganese oxide (such as LiMnO2 , LiMn2O4 ), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi1 / 3Co1 / 3Mn1 / 3O2 (also referred to as NCM333 ), LiNi0.5Co0.2Mn0.3O2 (also referred to as NCM523 ) , LiNi0.5Co0.25Mn0.25O2 (also referred to as NCM211 ) , LiNi0.6Co0.2Mn0.2O2 (also referred to as NCM622 ), LiNi0.8Co0.1Mn0.1O2 (also referred to as NCM811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05
  • lithium-containing phosphates with an olivine structure may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO 4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO 4 ), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.
  • lithium iron phosphate such as LiFePO 4 (also referred to as LFP)
  • LiMnPO 4 lithium manganese phosphate
  • LiMnPO 4 lithium manganese phosphate
  • LiMnPO 4 lithium manganese phosphate and carbon
  • the positive electrode film layer may further optionally include a binder.
  • the binder may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resin.
  • PVDF polyvinylidene fluoride
  • PTFE polytetrafluoroethylene
  • VDF polytetrafluoroethylene
  • PTFE polytetrafluoroethylene
  • vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer
  • the positive electrode film layer may further include a conductive agent, which may include, for example, at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
  • a conductive agent which may include, for example, at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
  • the positive electrode sheet can be prepared in the following manner: the components for preparing the positive electrode sheet, such as the positive electrode active material, the conductive agent, the binder and any other components are dispersed in a solvent (such as N-methylpyrrolidone) to form a positive electrode slurry; the positive electrode slurry is coated on the positive electrode collector, and after drying, cold pressing and other processes, the positive electrode sheet can be obtained.
  • a solvent such as N-methylpyrrolidone
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode film layer arranged on at least one surface of the negative electrode current collector, the negative electrode film layer includes a negative electrode active material, and the negative electrode active material includes the negative electrode active material described in the first aspect of the present application.
  • the negative electrode current collector has two surfaces opposite to each other in its thickness direction, and the negative electrode film layer is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.
  • the negative electrode current collector may be a metal foil or a composite current collector.
  • the metal foil copper foil may be used.
  • the composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material substrate.
  • the composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
  • PP polypropylene
  • PET polyethylene terephthalate
  • PBT polybutylene terephthalate
  • PS polystyrene
  • PE polyethylene
  • the negative electrode active materials of the present application may also include negative electrode active materials for batteries known in the art, such as artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate.
  • the silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys.
  • the tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys.
  • the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.
  • the negative electrode film layer may further include a binder.
  • the binder may be selected from at least one of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA) and carboxymethyl chitosan (CMCS).
  • the negative electrode film layer may further include a conductive agent, which may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • a conductive agent which may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • the negative electrode film layer may optionally include other additives, such as a thickener (eg, sodium carboxymethyl cellulose (CMC-Na)).
  • a thickener eg, sodium carboxymethyl cellulose (CMC-Na)
  • the negative electrode sheet can be prepared in the following manner: the components for preparing the negative electrode sheet, such as the negative electrode active material, the conductive agent, the binder and any other components are dispersed in a solvent (such as deionized water) to form a negative electrode slurry; the negative electrode slurry is coated on the negative electrode collector, and after drying, cold pressing and other processes, the negative electrode sheet can be obtained.
  • a solvent such as deionized water
  • the electrolyte plays the role of conducting ions between the positive electrode and the negative electrode.
  • the present application has no specific restrictions on the type of electrolyte, which can be selected according to needs.
  • the electrolyte can be liquid, gel or all-solid.
  • the electrolyte is an electrolyte solution, which includes an electrolyte salt and a solvent.
  • the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.
  • the solvent can be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane sulfone, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone.
  • the electrolyte may further include additives, such as negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, additives that improve battery high or low temperature performance, etc.
  • additives such as negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, additives that improve battery high or low temperature performance, etc.
  • the secondary battery further includes a separator.
  • the present application has no particular limitation on the type of separator, and any known porous separator with good chemical stability and mechanical stability can be selected.
  • the material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.
  • the isolation membrane can be a single-layer film or a multi-layer composite film, without particular limitation.
  • the materials of each layer can be the same or different, without particular limitation.
  • the positive electrode sheet, the negative electrode sheet, and the separator may be formed into an electrode assembly by a winding process or a lamination process.
  • the secondary battery may include an outer package that can be used to encapsulate the electrode assembly and the electrolyte.
  • the outer packaging of the secondary battery may be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc.
  • the outer packaging of the secondary battery may also be a soft package, such as a bag-type soft package.
  • the material of the soft package may be plastic, and examples of the plastic include polypropylene, polybutylene terephthalate, and polybutylene succinate.
  • FIG1 is a secondary battery 1 of a square structure as an example.
  • the outer package may include a shell 11 and a cover plate 13.
  • the shell 11 may include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate enclose a receiving cavity.
  • the shell 11 has an opening connected to the receiving cavity, and the cover plate 13 can be covered on the opening to close the receiving cavity.
  • the positive electrode sheet, the negative electrode sheet and the isolation film can form an electrode assembly 12 through a winding process or a lamination process.
  • the electrode assembly 12 is encapsulated in the receiving cavity.
  • the electrolyte is infiltrated in the electrode assembly 12.
  • the number of electrode assemblies 12 contained in the secondary battery 1 can be one or more, and those skilled in the art can select according to specific actual needs.
  • secondary batteries may be assembled into a battery module.
  • the number of secondary batteries contained in the battery module may be one or more, and the specific number may be selected by those skilled in the art according to the application and capacity of the battery module.
  • the battery modules described above may also be assembled into a battery pack.
  • the battery pack may contain one or more battery modules, and the specific number may be selected by those skilled in the art according to the application and capacity of the battery pack.
  • the present application also provides an electrical device, which includes at least one of the secondary battery, battery module, or battery pack provided in the present application.
  • the secondary battery, battery module, or battery pack can be used as a power source for the electrical device, and can also be used as an energy storage unit for the electrical device.
  • the electrical device may include mobile devices, electric vehicles, electric trains, ships and satellites, energy storage systems, etc., but are not limited to these.
  • the mobile device may be, for example, a mobile phone, a laptop computer, etc.;
  • the electric vehicle may be, for example, a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, etc., but are not limited to these.
  • a secondary battery, a battery module or a battery pack may be selected according to its usage requirements.
  • Fig. 3 shows an example of an electric device 2.
  • the electric device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle.
  • the device may be a mobile phone, a tablet computer, a laptop computer, etc.
  • the positive electrode active material ternary material nickel cobalt manganese (NCM811), the conductive agent acetylene black, and the binder polyvinylidene fluoride (PVDF) are mixed evenly in a mass ratio of 97:2:1 and added into the solvent NMP to prepare the positive electrode slurry; the positive electrode slurry is evenly coated on the positive electrode collector aluminum foil, dried at 85°C and then cold pressed, and then die-cut and slit to prepare the lithium-ion battery positive electrode sheet.
  • Artificial graphite in terms of mass percentage, small-sized particles with a D50 particle size of 5 ⁇ m account for 40%, and large-sized particles with a D50 particle size of 25 ⁇ m account for 60%
  • dodecylamine are mixed in a mass ratio of 100:20, and water is used as a solvent to prepare a dispersion liquid.
  • the stable aqueous dispersion liquid is centrifuged at a speed of 10,000 rpm, and solid-liquid separation is performed to retain the solid phase, thereby obtaining a carbon-based material with amino groups on the surface, which is positively charged;
  • Si (D50 particle size of 5 ⁇ m) and sodium cholate were mixed in a mass ratio of 100:20, and water was used as a solvent to prepare a dispersion.
  • the solid-liquid separation was performed to retain the liquid phase, and the concentration of the obtained liquid phase was a stable aqueous dispersion of 50 mg/mL; the stable aqueous dispersion was centrifuged at a speed of 10,000 rpm, and the solid-liquid separation was performed to retain the solid phase, thereby obtaining a silicon-based material with carboxyl groups on the surface, which was negatively charged;
  • the carbon-based material having amino groups on the surface and the silicon-based material having carboxyl groups on the surface are mixed in a mass ratio of 50:50 to obtain a negative electrode active material;
  • the negative electrode active material prepared in step a, the conductive agent acetylene black, the thickener sodium carboxymethyl cellulose (CMC), and the binder styrene butadiene rubber (SBR) are added to the solvent water in a mass ratio of 96:2:1:1, mixed evenly and prepared into a negative electrode slurry with a solid content of 50%; the negative electrode slurry is evenly coated on the negative electrode current collector copper foil, dried at 85°C and then cold pressed to prepare a lithium ion battery negative electrode sheet.
  • a polyethylene microporous film is used as a porous isolation membrane substrate, and inorganic alumina powder, polyvinylpyrrolidone, and acetone solvent are evenly mixed in a weight ratio of 3:1.5:5.5 to form a slurry, which is then coated on one side of the substrate and dried to obtain an isolation membrane.
  • Lithium hexafluorophosphate is dissolved in a mixed solvent of ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate (the volume ratio of ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate is 1:2:1) to obtain a lithium ion battery electrolyte.
  • the positive electrode sheet, negative electrode sheet and isolation film are wound to obtain an electrode assembly, and then a lithium-ion battery is obtained through the processes of packaging, liquid injection, formation and exhaust.
  • the N/P of the battery is 1, and the battery design rated capacity is 100Ah.
  • step (2) artificial graphite is mixed with sodium cholate to prepare a carbon-based material having carboxyl groups on the surface and having a negative charge; Si is mixed with dodecylamine to prepare a silicon-based material having amino groups on the surface and having a positive charge.
  • the method is basically the same as Example 1, except that in step (2) a, a carbon-based material having amino groups on its surface and a silicon-based material having carboxyl groups on its surface are mixed in a mass ratio of 97:3 to obtain a negative electrode active material.
  • the method is basically the same as Example 1, except that in step (2) a, a carbon-based material having amino groups on its surface and a silicon-based material having carboxyl groups on its surface are mixed in a mass ratio of 20:80 to obtain a negative electrode active material.
  • the method is basically the same as Example 1, except that in step (2)a, all artificial graphite particles are small-sized particles with a D50 particle size of 5 ⁇ m.
  • the method is basically the same as Example 1, except that in step (2)a, all artificial graphite particles are large-sized particles with a D50 particle size of 25 ⁇ m.
  • step (2)a Basically the same as Example 1, except that in step (2)a, the D50 particle size of Si is 0.2 ⁇ m.
  • step (2)a the D50 particle size of Si is 100 ⁇ m.
  • step (2) a is as follows:
  • Natural graphite in terms of mass percentage, small-sized particles with a D50 particle size of 1 ⁇ m account for 80%, and large-sized particles with a D50 particle size of 95 ⁇ m account for 20%
  • ethoxyboric acid diglyceride are mixed in a mass ratio of 100:20, and water is used as a solvent to prepare a dispersion liquid.
  • the stable aqueous dispersion liquid is centrifuged at a speed of 10,000 rpm, and solid-liquid separation is performed to retain the solid phase, thereby obtaining a carbon-based material with boric acid groups on the surface, which is positively charged;
  • Si D50 particle size of 30 ⁇ m
  • sodium dodecylbenzene sulfonate were mixed in a mass ratio of 100:20, and water was used as a solvent to prepare a dispersion.
  • the solid-liquid separation was performed to retain the liquid phase, and the concentration of the obtained liquid phase was a stable aqueous dispersion of 50 mg/mL; the stable aqueous dispersion was centrifuged at a speed of 10,000 rpm, and the solid-liquid separation was performed to retain the solid phase, and a silicon-based material with sulfonic acid groups on the surface was obtained, which was negatively charged;
  • the carbon-based material having a boric acid group on the surface and the silicon-based material having a sulfonic acid group on the surface are mixed in a mass ratio of 5:95 to obtain a negative electrode active material.
  • step (2) a is as follows: hard carbon (in terms of mass percentage, small-sized particles with a D50 particle size of 5 ⁇ m account for 50%, and large-sized particles with a D50 particle size of 50 ⁇ m account for 50%) and hexadecanoic acid amide are mixed in a mass ratio of 100:20, and water is used as a solvent to prepare a dispersion liquid.
  • the solid-liquid separation is performed to retain the liquid phase, and the concentration of the obtained liquid phase is a stable aqueous dispersion liquid of 50 mg/mL; the stable aqueous dispersion liquid is centrifuged at a speed of 10000 rpm, and the solid-liquid separation is performed to retain the solid phase, thereby obtaining a carbon-based material with amide groups on the surface, which is positively charged;
  • Si (D50 particle size of 50 ⁇ m) and hexadecyl bromide were mixed in a mass ratio of 100:20, and water was used as a solvent to prepare a dispersion.
  • the solid-liquid separation was performed to retain the liquid phase, and the concentration of the obtained liquid phase was a stable aqueous dispersion of 50 mg/mL; the stable aqueous dispersion was centrifuged at a speed of 10,000 rpm, and the solid-liquid separation was performed to retain the solid phase, and a silicon-based material with bromine atoms on the surface was obtained, which was negatively charged;
  • the carbon-based material having amide groups on the surface and the silicon-based material having bromine atoms on the surface are mixed in a mass ratio of 70:30 to obtain a negative electrode active material.
  • step (2) a is as follows:
  • the secondary battery was charged at a constant current of 0.33C to 4.3V, then charged at a constant voltage to a current of 0.05C, allowed to stand for 5 minutes, and then discharged at a constant current of 0.33C to 2.5V. The discharge capacity at this time was recorded, which was the 0.33C discharge capacity.
  • the secondary batteries of each embodiment and comparative example were charged to 4.3V at a constant current of 0.33C, then charged at a constant voltage to a current of 0.05C, allowed to stand for 5 min, and then discharged to 2.5V at a constant current of 0.1C, and the discharge capacity at this time was recorded, which was the 0.33C discharge capacity; allowed to stand for 30 min, and then the secondary battery was charged to 4.3V at a constant current of 1.0C, then charged to a current of 0.05C at a constant voltage, allowed to stand for 5 min, and then discharged to 2.5V at a constant current of 1C, and the discharge capacity at this time was recorded, which was the 1C discharge capacity.
  • Example 3 Analyzing the data in Table 3, compared with Example 1, the electrical properties of the negative electrode active material in Example 2 are opposite, the silicon-based material is positively charged and the carbon-based material is negatively charged. Since the agglomeration of silicon will have a greater negative impact on the performance of the battery than the agglomeration of carbon, especially in the high silicon system, when the silicon content in the negative electrode active material is as high as 50%, the silicon-negative-carbon-positive scheme of Example 1 has a greater advantage than the silicon-positive-carbon-negative scheme of Example 2, because the silicon-negative-carbon-positive scheme can effectively improve the agglomeration of silicon and the conductive agent; the silicon content in Example 3 is lower, although the capacity retention rate is improved compared with that in Example 1, the 0.33C capacity of the battery prepared under the same conditions is too low; in Example 4, the silicon content is too high, and the dispersion is more difficult than in Example 1.
  • Example 5 Although the 0.33C capacity is improved to a certain extent, the capacity retention is The rate is significantly reduced; in Example 5, small-particle carbon materials are used. Since small particles have many defects and low specific capacity, the capacity of 0.33C is also lower than that of Example 1; in Example 6, large-particle carbon materials are used, which will lead to deterioration of battery kinetics and various performances are lower than those of Example 1; in Example 7, the silicon particles are smaller, the agglomeration phenomenon is aggravated, and the capacity retention rate is reduced; in Example 8, the silicon particles are larger, which will also lead to deterioration of kinetics and degradation of various performances.
  • Examples 9 and 10 show that the scheme of the present application is applicable to different types of functional groups.
  • Comparative Example 1 the surfaces of the carbon-based raw materials and the silicon-based raw materials were not surface treated, and they were severely agglomerated after mixing, resulting in a serious decrease in the capacity retention rate compared with the various embodiments, greatly reducing the rate performance of the battery.

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Abstract

一种负极活性材料，包括碳基材料和硅基材料，碳基材料的表面存在第一官能团，硅基材料的表面存在第二官能团，第一官能团携带有与第二官能团相反的电荷。

Description

负极活性材料及其制备方法、二次电池及其制备方法、用电装置 技术领域
本申请涉及二次电池领域，更具体地涉及负极活性材料及其制备方法、二次电池及其制备方法、用电装置。
背景技术
这里的陈述仅提供与本申请有关的背景信息，而不必然构成现有技术。
为满足市场对高性能动力电池的需求，可将具有高比容量的硅基材料替代石墨，提升电池的能量密度。然而，硅基材料充电后体积膨胀远大于石墨，其本身极化大，会恶化阳极的动力学。因此，为了获得性能更平衡的阳极，往往需要将硅基材料与碳基材料复配成混阳极材料。
传统技术中，往往采用简单的物理混合对硅基材料和碳基材料进行处理，这样的处理方式难以避免同类型颗粒之间的团聚，例如硅基材料颗粒彼此间的团聚，或碳基材料颗粒彼此间的团聚。特别是相比于石墨，硅颗粒团聚更容易导致阳极局部嵌锂浓差大，进而导致电芯膨胀力过大，动力学差以及析锂等安全问题，其中，最直接的体现就是电池倍率性能的下降。
发明内容
根据本申请的各种实施例，本申请的第一方面，提供了一种负极活性材料，包括碳基材料和硅基材料，所述碳基材料的表面存在第一官能团，所述硅基材料的表面存在第二官能团，所述第一官能团携带有与所述第二官能团相反的电荷。
本申请通过在碳基材料和硅基材料表面修饰带有相反电荷的官能团，能够使得同类型的材料颗粒之间由于带有同种电荷而互相排斥，避免了同类型颗粒之间的团聚，不同类型的材料颗粒则带有相反电荷存在一定的静电作用，从而使整个体系中不同类型的活性材料能够均匀分布，有效避免了传统技术中由于颗粒分布不均导致的倍率性能下降、电芯局部膨胀导致的厚度不均以及析锂等问题。
在一些实施方式中，所述第一官能团携带的电荷为正电荷，所述第二官能团携带的电荷为负电荷。其余条件不变的情况下，由于硅团聚后较碳团聚后对电池的性能造成的负面影响更严重，因此，当硅带负电荷碳带正电荷时，能够有效避免硅与导电剂 之间的团聚，从而进一步改善整个体系的分散性能，提升电池倍率性能。特别是在高硅含量的体系中，硅负碳正的方案将具备更加明显的优势。
在一些实施方式中，所述第一官能团包括氨基、酰胺基、氰基以及硼酸基中的一种或多种。
在一些实施方式中，所述第二官能团包括羧基、磺酸基、羟基以及卤素基中的一种或多种。
合适的官能团种类不仅能够防止颗粒团聚，改善体系的分散性，且不会对电池的其他性能造成不利影响。
在一些实施方式中，所述硅基材料在所述负极活性材料中的质量百分含量为1％～99％；可选地，所述硅基材料在所述负极活性材料中的质量百分含量为25％～85％。
在一些实施方式中，所述碳基材料在所述负极活性材料中的质量百分含量为1％～99％；可选地，所述碳基材料在所述负极活性材料中的质量百分含量为15％～75％。
控制负极活性材料中硅基材料和碳基材料的占比在合适范围内，能够平衡电池的容量和倍率性能之间的矛盾，使得电池的综合性能最大化；同时，还能够使得负极活性材料整体电性合适，从而在制备负极浆料时进一步改善浆料的分散稳定性。
在一些实施方式中，所述碳基材料包括小尺寸颗粒和大尺寸颗粒，所述小尺寸颗粒的D50粒径为0.2μm～9.99μm，所述大尺寸颗粒的D50粒径为10μm～100μm。碳基材料采用一定粒径范围的大尺寸颗粒和小尺寸颗粒进行复配，能够有效降低材料缺陷，提升电池容量，同时不会造成电池动力学性能过度恶化。
在一些实施方式中，所述小尺寸颗粒在所述负极活性材料中的质量百分含量为1％～99％，所述大尺寸颗粒在所述负极活性材料中的质量百分含量为1％～99％；可选地，所述小尺寸颗粒在所述负极活性材料中的质量百分含量为5％～75％，所述大尺寸颗粒在所述负极活性材料中的质量百分含量为25％～95％。控制大尺寸颗粒和小尺寸颗粒的占比在合适范围内，能够使得两者复配的效果更好，进一步提升电池的倍率性能。
在一些实施方式中，所述硅基材料的D50粒径为0.2μm～100μm；可选地，所述硅基材料的D50粒径为0.2μm～30μm。控制硅基材料的粒径在合适范围内，能够平衡电池容量和动力学性能，使得电池具备更佳的综合性能。
在一些实施方式中，所述负极活性材料满足以下(1)～(2)中的至少一个条件：
(1)所述碳基材料的稳定水分散液的浓度为0.1mg/mL～100mg/mL；
(2)所述硅基材料的稳定水分散液的浓度为0.1mg/mL～100mg/mL；
其中，所述稳定水分散液是指采用水作为溶剂、配置后静置2h以上不出现沉淀的分散液经固液分离后得到的液相。
控制材料的稳定水分散液浓度在合适范围内，才能使得材料带上电荷且电量合适，从而帮助进一步提高体系的分散稳定性。
本申请的第二方面，提供了前述一种或多种实施方式所述的负极活性材料的制备方法，包括以下步骤：
将碳基原料、第一表面活性剂和溶剂混合，制备第一分散液，静止2h以上后进行固液分离，保留液相，得到第一稳定分散液；对所述第一稳定分散液进行离心分离处理，得到第一沉淀；所述第一沉淀经洗涤、干燥得到所述碳基材料；
将硅基原料、第二表面活性剂和溶剂混合，制备第二分散液，静止2h以上后进行固液分离，保留液相，得到第二稳定分散液；对所述第二稳定分散液进行离心分离处理，得到第二沉淀；所述第二沉淀经洗涤、干燥得到所述硅基材料；
将所述碳基材料和所述硅基材料混合，制备所述负极活性材料；
其中，所述第一表面活性剂和所述第二表面活性剂在溶剂中分别携带有相反的电荷。
合适的制备方法能使原料均匀地带上电荷且电量适中，进一步提升负极活性材料的分散性能，降低团聚。
在一些实施方式中，所述制备方法满足以下(1)～(5)中的一个或多个条件：
(1)所述碳基原料包括人造石墨、天然石墨、软炭以及硬炭中的一种或多种；
(2)所述硅基原料包括Si以及SiO x(0<x<2)中的一种或多种；
(3)所述第一表面活性剂和第二表面活性剂分别独立地选自以下的一种或多种：十二胺、十六酰胺、十二腈、乙氧基硼酸双甘油酯、胆酸钠、十二烷基苯磺酸钠、癸炔二醇以及十六烷基溴；合适种类的表面活性剂能使得原料表面带上合适种类的官能团，提供电荷、改善材料分散性能的同时不会导致电池其他性能受损；
(4)所述第一表面活性剂的用量为所述碳基原料质量的0.1％～40％；合适的表面活性剂用量能使得所得碳基材料表面均匀地带上合适数量的电荷；
(5)所述第二表面活性剂的用量为所述硅基原料质量的0.1％～40％，合适的表面活性剂用量能使得所得硅基材料表面均匀地带上合适数量的电荷。
本申请的第三方面，提供了一种二次电池，包括正极极片、负极极片和隔离膜，所述隔离膜设置于所述正极极片和所述负极极片之间；
其中，所述负极极片包括负极集流体和设置于所述负极集流体至少一个表面的负极活性材料层，所述负极活性材料层包括前述一种多种实施方式所述的负极活性材料。
本申请的第四方面，提供了一种二次电池的制备方法，包括以下步骤：
提供正极集流体，在所述正极集流体表面涂覆正极浆料，干燥、压制，得到正极极片；
提供负极集流体，在所述负极集流体表面涂覆负极浆料，干燥、压制，得到负极极片；其中，所述负极浆料包括前述一种或多种实施方式所述的负极活性材料；可选地，所述负极浆料的固含量为30％～70％；合适的浆料固含量能更匹配本申请的技术方案，进一步提高负极活性材料中各类颗粒的分散稳定性，避免团聚；
将所述正极极片、隔离膜以及所述负极极片进行层叠或卷绕，制备所述二次电池。
本申请的第五方面，提供了一种用电装置，包括前述的二次电池或前述的制备方法制得的二次电池。
附图说明
为了更好地描述和说明这里公开的那些发明的实施例或示例，可以参考一幅或多幅附图。用于描述附图的附加细节或示例不应当被认为是对所公开的发明、目前描述的实施例或示例以及目前理解的这些发明的最佳模式中的任何一者的范围的限制。
图1是本申请一实施方式的二次电池的示意图。
图2是图1所示的本申请一实施方式的二次电池的分解图。
图3是本申请一实施方式的二次电池用作电源的用电装置的示意图。
附图标记说明：
1：二次电池；11：壳体；12：电极组件；13：盖板；2：用电装置。
具体实施方式
为了使本申请的目的、技术方案及优点更加清楚明白，以下结合附图及实施例，对本申请进行进一步详细说明。应当理解，此处描述的具体实施例仅仅用以解释本申请，并不用于限定本申请。
除非另有定义，本文所使用的所有的技术和科学术语与属于本申请的技术领域的技术人员通常理解的含义相同。本文中在本申请的说明书中所使用的术语只是为了描述具体的实施例的目的，不是旨在于限制本申请。
本申请所公开的“范围”以下限和上限的形式来限定，给定范围是通过选定一个 下限和一个上限进行限定的，选定的下限和上限限定了特别范围的边界。这种方式进行限定的范围可以是包括端值或不包括端值的，并且可以进行任意地组合，即任何下限可以与任何上限组合形成一个范围。例如，如果针对特定参数列出了60-120和80-110的范围，理解为60-110和80-120的范围也是预料到的。此外，如果列出的最小范围值1和2，和如果列出了最大范围值3，4和5，则下面的范围可全部预料到：1-3、1-4、1-5、2-3、2-4和2-5。在本申请中，除非有其他说明，数值范围“a-b”表示a到b之间的任意实数组合的缩略表示，其中a和b都是实数。例如数值范围“0-5”表示本文中已经全部列出了“0-5”之间的全部实数，“0-5”只是这些数值组合的缩略表示。另外，当表述某个参数为≥2的整数，则相当于公开了该参数为例如整数2、3、4、5、6、7、8、9、10、11、12等。
如果没有特别的说明，本申请的所有实施方式以及可选实施方式可以相互组合形成新的技术方案。
如果没有特别的说明，本申请的所有技术特征以及可选技术特征可以相互组合形成新的技术方案。
如果没有特别的说明，本申请的所有步骤可以顺序进行，也可以随机进行，优选是顺序进行的。例如，所述方法包括步骤(a)和(b)，表示所述方法可包括顺序进行的步骤(a)和(b)，也可以包括顺序进行的步骤(b)和(a)。例如，所述提到所述方法还可包括步骤(c)，表示步骤(c)可以任意顺序加入到所述方法，例如，所述方法可以包括步骤(a)、(b)和(c)，也可包括步骤(a)、(c)和(b)，也可以包括步骤(c)、(a)和(b)等。
如果没有特别的说明，本申请所提到的“包括”和“包含”表示开放式，也可以是封闭式。例如，所述“包括”和“包含”可以表示还可以包括或包含没有列出的其他组分，也可以仅包括或包含列出的组分。
如果没有特别的说明，在本申请中，术语“或”是包括性的。举例来说，短语“A或B”表示“A，B，或A和B两者”。更具体地，以下任一条件均满足条件“A或B”：A为真(或存在)并且B为假(或不存在)；A为假(或不存在)而B为真(或存在)；或A和B都为真(或存在)。
硅基材料由于具有高理论比容量和更低的析锂风险，已被逐渐用作负极活性材料，以满足市场对于高容量二次电池日益增长的需求。然而，硅基材料由于膨胀系数较高，本身极化较大，通常需要跟石墨等碳基材料混合使用，以平衡比容量和膨胀系数之间的矛盾，提升电池的综合性能。然而，当硅、碳两种材料混合使用时，常常难以分散 均匀，特别是硅基材料，发生团聚后会对电池的性能造成显著的负面影响，容易导致局部过度膨胀、倍率性能下降等问题。
基于上述背景，本申请的第一方面，提供了一种负极活性材料，包括碳基材料和硅基材料，碳基材料的表面存在第一官能团，硅基材料的表面存在第二官能团，第一官能团携带有与第二官能团相反的电荷。
本申请通过在碳基材料和硅基材料表面修饰带有相反电荷的官能团，能够使得同类型的材料颗粒之间由于带有同种电荷而互相排斥，避免了同类型颗粒之间的团聚，不同类型的材料颗粒则带有相反电荷存在一定的静电作用，从而使整个体系中不同类型的活性材料能够均匀分布，有效避免了传统技术中由于颗粒分布不均导致的倍率性能下降、过度膨胀、析锂等问题。
在一些实施方式中，第一官能团携带的电荷为正电荷，第二官能团携带的电荷为负电荷。其余条件不变的情况下，由于硅团聚后较碳团聚后对电池的性能造成的负面影响更严重，因此，当硅带负电荷碳带正电荷时，能够有效避免硅与导电剂之间的团聚，从而进一步改善整个体系的分散性能，提升电池倍率性能。特别是在高硅含量(硅基材料质量百分含量20％以上)的体系中，硅负碳正的方案将具备更加明显的优势。
在一些实施方式中，第一官能团包括氨基、酰胺基、氰基以及硼酸基中的一种或多种。
在一些实施方式中，第二官能团包括羧基、磺酸基、羟基以及卤素基中的一种或多种。
合适的官能团种类不仅能够防止颗粒团聚，改善体系的分散性，且不会对电池的其他性能造成不利影响。可以理解，官能团的存在是为了使得负极材料颗粒能带上电荷，因此，并不对材料表面存在的具体的取代基进行限定，只要含有上述官能团且能够正常带电即可。例如，氨基可以仅仅是单独的氨基，也可以是存在于-CH 2NH 2中的氨基，还可以是存在于-COOCH 2NH 2中的氨基；再例如，羧基可以是单独的羧基，也可以是-CH 2COOH；又例如，卤素基可以是单独的氟原子，也可以是全氟烷基。本申请中，卤素基包括-F、-Cl以及-Br中的一种或多种。
在一些实施方式中，硅基材料在负极活性材料中的质量百分含量为1％～99％；可选地，硅基材料在负极活性材料中的质量百分含量例如可以是25％～85％，又如还可以是5％、10％、15％、20％、25％、30％、35％、40％、45％、50％、55％、60％、65％、70％、75％、80％、85％、90％或95％。
在一些实施方式中，碳基材料在负极活性材料中的质量百分含量为1％～99％；可选地，碳基材料在负极活性材料中的质量百分含量例如可以是15％～75％，又如还可以是5％、10％、15％、20％、25％、30％、35％、40％、45％、50％、55％、60％、65％、70％、75％、80％、85％、90％或95％。
控制负极活性材料中硅基材料和碳基材料的占比在合适范围内，能够平衡电池的容量和倍率性能之间的矛盾，使得电池的综合性能最大化；同时，还能够使得负极活性材料整体电性合适，从而在制备负极浆料时进一步改善浆料的分散稳定性。
在一些实施方式中，碳基材料包括小尺寸颗粒和大尺寸颗粒，小尺寸颗粒的D50粒径为0.2μm～9.9μm，大尺寸颗粒的D50粒径为10μm～100μm。可选地，小尺寸颗粒的D50粒径例如还可以是0.5μm、1μm、1.5μm、2μm、2.5μm、3μm、3.5μm、4μm、4.5μm、5μm、5.5μm、6μm、6.5μm、7μm、7.5μm、8μm、8.5μm、9μm或9.5μm。可选地，大尺寸颗粒的D50粒径例如还可以是15μm、20μm、25μm、30μm、35μm、40μm、45μm、50μm、55μm、60μm、65μm、70μm、75μm、80μm、85μm、90μm或95μm。碳基材料采用一定粒径范围的大尺寸颗粒和小尺寸颗粒进行复配，能够有效降低材料缺陷，提升电池容量，同时不会造成电池动力学性能过度恶化。
本申请中，D50指：在粒度累积分布曲线中，颗粒的累计分布数达到50％时所对应的粒径，它的物理意义是粒径小于(或大于)该粒径值的颗粒的数量占比各为50％。作为示例，D50可以参照GB/T 19077-2016粒度分布激光衍射法，采用激光粒度分析仪方便地测定，如英国马尔文仪器有限公司的Mastersizer 2000E型激光粒度分析仪。
在一些实施方式中，小尺寸颗粒在负极活性材料中的质量百分含量为1％～99％，大尺寸颗粒在负极活性材料中的质量百分含量为1％～99％；可选地，小尺寸颗粒在负极活性材料中的质量百分含量为5％～75％，大尺寸颗粒在负极活性材料中的质量百分含量为25％～95％。小尺寸颗粒在负极活性材料中的质量百分含量例如还可以是5％、10％、15％、20％、25％、30％、35％、40％、45％、50％、55％、60％、65％、70％、75％、80％、85％、90％或95％。大尺寸颗粒在负极活性材料中的质量百分含量例如还可以是5％、10％、15％、20％、25％、30％、35％、40％、45％、50％、55％、60％、65％、70％、75％、80％、85％、90％或95％。控制大尺寸颗粒和小尺寸颗粒的占比在合适范围内，能够使得两者复配的效果更好，进一步提升电池的倍率性能。
在一些实施方式中，硅基材料的D50粒径为0.2μm～100μm；可选地，硅基材料 的D50粒径为0.2μm～30μm，硅基材料的D50粒径例如还可以是5μm、10μm、15μm、20μm、25μm、30μm、35μm、40μm、45μm、50μm、55μm、60μm、65μm、70μm、75μm、80μm、85μm、90μm或95μm。控制硅基材料的粒径在合适范围内，能够平衡电池容量和动力学性能，使得电池具备更佳的综合性能。
在一些实施方式中，负极活性材料满足以下(1)～(2)中的至少一个条件：
(1)碳基材料的稳定水分散液的浓度为0.1mg/mL～100mg/mL；碳基材料的稳定水分散液的浓度例如还可以是10mg/mL、20mg/mL、30mg/mL、40mg/mL、50mg/mL、60mg/mL、70mg/mL、80mg/mL或90mg/mL；
(2)硅基材料的稳定水分散液的浓度为0.1mg/mL～100mg/mL；硅基材料的稳定水分散液的浓度例如还可以是10mg/mL、20mg/mL、30mg/mL、40mg/mL、50mg/mL、60mg/mL、70mg/mL、80mg/mL或90mg/mL；
其中，稳定水分散液是指采用水作为溶剂、配置后静置2h以上不出现沉淀的分散液经固液分离后得到的液相。
控制材料的稳定水分散液浓度在合适范围内，才能使得材料带上电荷且电量合适，从而帮助进一步提高体系的分散稳定性。
本申请的第二方面，提供了前述一种或多种实施方式的负极活性材料的制备方法，包括以下步骤：
将碳基原料、第一表面活性剂和溶剂混合，制备第一分散液，静止2h以上后进行固液分离，保留液相，得到第一稳定分散液；对第一稳定分散液进行离心分离处理，得到第一沉淀；第一沉淀经洗涤、干燥得到碳基材料；
将硅基原料、第二表面活性剂和溶剂混合，制备第二分散液，静止2h以上后进行固液分离，保留液相，得到第二稳定分散液；对第二稳定分散液进行离心分离处理，得到第二沉淀；第二沉淀经洗涤、干燥得到硅基材料；
将碳基材料和硅基材料混合，制备负极活性材料；
其中，第一表面活性剂和第二表面活性剂在溶剂中分别携带有相反的电荷。
合适的制备方法能使原料均匀地带上电荷且电量适中，进一步提升负极活性材料的分散性能，降低团聚。
在一些实施方式中，制备方法满足以下(1)～(5)中的一个或多个条件：
(1)碳基原料包括人造石墨、天然石墨、软炭以及硬炭中的一种或多种；
(2)硅基原料包括Si以及SiO x(0<x<2)中的一种或多种；
(3)第一表面活性剂和第二表面活性剂分别独立地选自以下的一种或多种：十二胺、十六酰胺、十二腈、乙氧基硼酸双甘油酯、胆酸钠、十二烷基苯磺酸钠、癸炔二醇以及十六烷基溴；合适种类的表面活性剂能使得原料表面带上合适种类的官能团，提供电荷、改善材料分散性能的同时不会导致电池其他性能受损，但可用的表面活性剂并不限于前述列出的种类，前述列出的种类仅是一些易得且效果较好的表面活性剂的代表；
(4)第一表面活性剂的用量为碳基原料质量的0.1％～40％；第一表面活性剂的用量例如还可以是碳基原料质量的5％、10％、15％、20％、25％、30％或35％。合适的表面活性剂用量能使得所得碳基材料表面均匀地带上合适数量的电荷；
(5)第二表面活性剂的用量为硅基原料质量的0.1％～40％；第二表面活性剂的用量例如还可以是硅基原料质量的5％、10％、15％、20％、25％、30％或35％。合适的表面活性剂用量能使得所得硅基材料表面均匀地带上合适数量的电荷。
本申请的第三方面，提供了一种二次电池，包括正极极片、负极极片和隔离膜，隔离膜设置于正极极片和负极极片之间；
其中，负极极片包括负极集流体和设置于负极集流体至少一个表面的负极活性材料层，负极活性材料层包括前述一种多种实施方式的负极活性材料。
本申请的第四方面，提供了一种二次电池的制备方法，包括以下步骤：
提供正极集流体，在正极集流体表面涂覆正极浆料，干燥、压制，得到正极极片；
提供负极集流体，在负极集流体表面涂覆负极浆料，干燥、压制，得到负极极片；其中，负极浆料包括前述一种或多种实施方式的负极活性材料；可选地，负极浆料的固含量为30％～70％；负极浆料的固含量例如还可以是35％、40％、45％、50％、55％、60％或65％。合适的浆料固含量能更匹配本申请的技术方案，进一步提高负极活性材料中各类颗粒的分散稳定性，避免团聚；
将正极极片、隔离膜以及负极极片进行层叠或卷绕，制备二次电池。
本申请的第五方面，提供了一种用电装置，包括前述的二次电池或前述的制备方法制得的二次电池。
另外，以下适当参照附图对本申请的二次电池和用电装置进行说明。
本申请的一个实施方式中，提供一种二次电池。
通常情况下，二次电池包括正极极片、负极极片、电解质和隔离膜。在电池充放电过程中，活性离子在正极极片和负极极片之间往返嵌入和脱出。电解质在正极极片 和负极极片之间起到传导离子的作用。隔离膜设置在正极极片和负极极片之间，主要起到防止正负极短路的作用，同时可以使离子通过。
正极极片
正极极片包括正极集流体以及设置在正极集流体至少一个表面的正极膜层，所述正极膜层包括正极活性材料。
作为示例，正极集流体具有在其自身厚度方向相对的两个表面，正极膜层设置在正极集流体相对的两个表面的其中任意一者或两者上。
在一些实施方式中，所述正极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可采用铝箔。复合集流体可包括高分子材料基层和形成于高分子材料基层至少一个表面上的金属层。复合集流体可通过将金属材料(铝、铝合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(如聚丙烯(PP)、聚对苯二甲酸乙二醇酯(PET)、聚对苯二甲酸丁二醇酯(PBT)、聚苯乙烯(PS)、聚乙烯(PE)等的基材)上而形成。
在一些实施方式中，正极活性材料可采用本领域公知的用于电池的正极活性材料。作为示例，正极活性材料可包括以下材料中的至少一种：橄榄石结构的含锂磷酸盐、锂过渡金属氧化物及其各自的改性化合物。但本申请并不限定于这些材料，还可以使用其他可被用作电池正极活性材料的传统材料。这些正极活性材料可以仅单独使用一种，也可以将两种以上组合使用。其中，锂过渡金属氧化物的示例可包括但不限于锂钴氧化物(如LiCoO 2)、锂镍氧化物(如LiNiO 2)、锂锰氧化物(如LiMnO 2、LiMn 2O 4)、锂镍钴氧化物、锂锰钴氧化物、锂镍锰氧化物、锂镍钴锰氧化物(如LiNi 1/3Co 1/3Mn 1/3O 2(也可以简称为NCM 333)、LiNi 0.5Co 0.2Mn 0.3O 2(也可以简称为NCM 523)、LiNi 0.5Co 0.25Mn 0.25O 2(也可以简称为NCM 211)、LiNi 0.6Co 0.2Mn 0.2O 2(也可以简称为NCM 622)、LiNi 0.8Co 0.1Mn 0.1O 2(也可以简称为NCM 811)、锂镍钴铝氧化物(如LiNi 0.85Co 0.15Al 0.05O 2)及其改性化合物等中的至少一种。橄榄石结构的含锂磷酸盐的示例可包括但不限于磷酸铁锂(如LiFePO 4(也可以简称为LFP))、磷酸铁锂与碳的复合材料、磷酸锰锂(如LiMnPO 4)、磷酸锰锂与碳的复合材料、磷酸锰铁锂、磷酸锰铁锂与碳的复合材料中的至少一种。
在一些实施方式中，正极膜层还可选地包括粘结剂。作为示例，所述粘结剂可以包括聚偏氟乙烯(PVDF)、聚四氟乙烯(PTFE)、偏氟乙烯-四氟乙烯-丙烯三元共聚物、偏氟乙烯-六氟丙烯-四氟乙烯三元共聚物、四氟乙烯-六氟丙烯共聚物及含氟丙烯 酸酯树脂中的至少一种。
在一些实施方式中，正极膜层还可选地包括导电剂。作为示例，所述导电剂可以包括超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯及碳纳米纤维中的至少一种。
在一些实施方式中，可以通过以下方式制备正极极片：将上述用于制备正极极片的组分，例如正极活性材料、导电剂、粘结剂和任意其他的组分分散于溶剂(例如N-甲基吡咯烷酮)中，形成正极浆料；将正极浆料涂覆在正极集流体上，经烘干、冷压等工序后，即可得到正极极片。
负极极片
负极极片包括负极集流体以及设置在负极集流体至少一个表面上的负极膜层，所述负极膜层包括负极活性材料，所述负极活性材料包括本申请第一方面所述的负极活性材料。
作为示例，负极集流体具有在其自身厚度方向相对的两个表面，负极膜层设置在负极集流体相对的两个表面中的任意一者或两者上。
在一些实施方式中，所述负极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可以采用铜箔。复合集流体可包括高分子材料基层和形成于高分子材料基材至少一个表面上的金属层。复合集流体可通过将金属材料(铜、铜合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(如聚丙烯(PP)、聚对苯二甲酸乙二醇酯(PET)、聚对苯二甲酸丁二醇酯(PBT)、聚苯乙烯(PS)、聚乙烯(PE)等的基材)上而形成。
在一些实施方式中，除了本申请第一方面所述的负极活性材料，本申请的负极活性材料还可包括本领域公知的用于电池的负极活性材料，例如：人造石墨、天然石墨、软炭、硬炭、硅基材料、锡基材料和钛酸锂等。所述硅基材料可选自单质硅、硅氧化合物、硅碳复合物、硅氮复合物以及硅合金中的至少一种。所述锡基材料可选自单质锡、锡氧化合物以及锡合金中的至少一种。但本申请并不限定于这些材料，还可以使用其他可被用作电池负极活性材料的传统材料。这些负极活性材料可以仅单独使用一种，也可以将两种以上组合使用。
在一些实施方式中，负极膜层还可选地包括粘结剂。所述粘结剂可选自丁苯橡胶(SBR)、聚丙烯酸(PAA)、聚丙烯酸钠(PAAS)、聚丙烯酰胺(PAM)、聚乙烯醇(PVA)、海藻酸钠(SA)、聚甲基丙烯酸(PMAA)及羧甲基壳聚糖(CMCS) 中的至少一种。
在一些实施方式中，负极膜层还可选地包括导电剂。导电剂可选自超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯及碳纳米纤维中的至少一种。
在一些实施方式中，负极膜层还可选地包括其他助剂，例如增稠剂(如羧甲基纤维素钠(CMC-Na))等。
在一些实施方式中，可以通过以下方式制备负极极片：将上述用于制备负极极片的组分，例如负极活性材料、导电剂、粘结剂和任意其他组分分散于溶剂(例如去离子水)中，形成负极浆料；将负极浆料涂覆在负极集流体上，经烘干、冷压等工序后，即可得到负极极片。
电解质
电解质在正极极片和负极极片之间起到传导离子的作用。本申请对电解质的种类没有具体的限制，可根据需求进行选择。例如，电解质可以是液态的、凝胶态的或全固态的。
在一些实施方式中，所述电解质采用电解液。所述电解液包括电解质盐和溶剂。
在一些实施方式中，电解质盐可选自六氟磷酸锂、四氟硼酸锂、高氯酸锂、六氟砷酸锂、双氟磺酰亚胺锂、双三氟甲磺酰亚胺锂、三氟甲磺酸锂、二氟磷酸锂、二氟草酸硼酸锂、二草酸硼酸锂、二氟二草酸磷酸锂及四氟草酸磷酸锂中的至少一种。
在一些实施方式中，溶剂可选自碳酸亚乙酯、碳酸亚丙酯、碳酸甲乙酯、碳酸二乙酯、碳酸二甲酯、碳酸二丙酯、碳酸甲丙酯、碳酸乙丙酯、碳酸亚丁酯、氟代碳酸亚乙酯、甲酸甲酯、乙酸甲酯、乙酸乙酯、乙酸丙酯、丙酸甲酯、丙酸乙酯、丙酸丙酯、丁酸甲酯、丁酸乙酯、1,4-丁内酯、环丁砜、二甲砜、甲乙砜及二乙砜中的至少一种。
在一些实施方式中，所述电解液还可选地包括添加剂。例如添加剂可以包括负极成膜添加剂、正极成膜添加剂，还可以包括能够改善电池某些性能的添加剂，例如改善电池过充性能的添加剂、改善电池高温或低温性能的添加剂等。
隔离膜
在一些实施方式中，二次电池中还包括隔离膜。本申请对隔离膜的种类没有特别的限制，可以选用任意公知的具有良好的化学稳定性和机械稳定性的多孔结构隔离膜。
在一些实施方式中，隔离膜的材质可选自玻璃纤维、无纺布、聚乙烯、聚丙烯及聚偏二氟乙烯中的至少一种。隔离膜可以是单层薄膜，也可以是多层复合薄膜，没有 特别限制。在隔离膜为多层复合薄膜时，各层的材料可以相同或不同，没有特别限制。
在一些实施方式中，正极极片、负极极片和隔离膜可通过卷绕工艺或叠片工艺制成电极组件。
在一些实施方式中，二次电池可包括外包装。该外包装可用于封装上述电极组件及电解质。
在一些实施方式中，二次电池的外包装可以是硬壳，例如硬塑料壳、铝壳、钢壳等。二次电池的外包装也可以是软包，例如袋式软包。软包的材质可以是塑料，作为塑料，可列举出聚丙烯、聚对苯二甲酸丁二醇酯以及聚丁二酸丁二醇酯等。
本申请对二次电池的形状没有特别的限制，其可以是圆柱形、方形或其他任意的形状。例如，图1是作为一个示例的方形结构的二次电池1。
在一些实施方式中，参照图2，外包装可包括壳体11和盖板13。其中，壳体11可包括底板和连接于底板上的侧板，底板和侧板围合形成容纳腔。壳体11具有与容纳腔连通的开口，盖板13能够盖设于所述开口，以封闭所述容纳腔。正极极片、负极极片和隔离膜可经卷绕工艺或叠片工艺形成电极组件12。电极组件12封装于所述容纳腔内。电解液浸润于电极组件12中。二次电池1所含电极组件12的数量可以为一个或多个，本领域技术人员可根据具体实际需求进行选择。
在一些实施方式中，二次电池可以组装成电池模块，电池模块所含二次电池的数量可以为一个或多个，具体数量本领域技术人员可根据电池模块的应用和容量进行选择。
在一些实施方式中，上述电池模块还可以组装成电池包，电池包所含电池模块的数量可以为一个或多个，具体数量本领域技术人员可根据电池包的应用和容量进行选择。
另外，本申请还提供一种用电装置，所述用电装置包括本申请提供的二次电池、电池模块、或电池包中的至少一种。所述二次电池、电池模块、或电池包可以用作所述用电装置的电源，也可以用作所述用电装置的能量存储单元。所述用电装置可以包括移动设备、电动车辆、电气列车、船舶及卫星、储能系统等，但不限于此。其中，移动设备例如可以是手机、笔记本电脑等；电动车辆例如可以是纯电动车、混合动力电动车、插电式混合动力电动车、电动自行车、电动踏板车、电动高尔夫球车、电动卡车等，但不限于此。
作为所述用电装置，可以根据其使用需求来选择二次电池、电池模块或电池包。
图3是作为一个示例的用电装置2。该用电装置为纯电动车、混合动力电动车、或插电式混合动力电动车等。
作为另一个示例的装置可以是手机、平板电脑、笔记本电脑等。
实施例1
(1)正极极片的制备
将正极活性物质三元材料镍钴锰(NCM811)、导电剂乙炔黑、粘结剂聚偏氟乙烯(PVDF)按质量比97：2：1混合均匀并加入到溶剂NMP中，制成正极浆料；将正极浆料均匀涂布在正极集流体铝箔上，在85℃下烘干后冷压，再进行模切、分条，制成锂离子电池正极片。
(2)负极极片的制备
a.负极活性材料的制备：
将人造石墨(按质量百分含量计，D50粒径为5μm的小尺寸颗粒占40％，D50粒径为25μm的大尺寸颗粒占60％)和十二胺按照质量比100：20混合，以水作为溶剂，配制成分散液，静置2h后，固液分离保留液相，所得液相的浓度为50mg/mL的稳定水分散液；将稳定水分散液在10000rpm的转速下离心，固液分离保留固相，得到表面存在氨基的碳基材料，带正电荷；
将Si(D50粒径为5μm)和胆酸钠按照质量比100：20混合，以水作为溶剂，配制成分散液，静置2h后，固液分离保留液相，所得液相的浓度为50mg/mL的稳定水分散液；将稳定水分散液在10000rpm的转速下离心，固液分离保留固相，得到表面存在羧基的硅基材料，带负电荷；
将表面存在氨基的碳基材料和表面存在羧基的硅基材料按照质量比50：50混合，得到负极活性材料；
b.将步骤a中制得的负极活性材料、导电剂乙炔黑、增稠剂羟甲基纤维素钠(CMC)、粘结剂丁苯橡胶(SBR)按质量比96：2：1：1加入溶剂水中混合均匀并制成固含量为50％的负极浆料；将负极浆料均匀涂布在负极集流体铜箔上，在85℃下烘干后进行冷压，制成锂离子电池负极片。
(3)隔离膜的制备
采用聚乙烯微孔薄膜作为多孔隔离膜基材，将无机三氧化铝粉末、聚乙烯呲咯烷酮、丙酮溶剂按重量比3：1.5：5.5混合均匀制成浆料并涂布于基材的一面并烘干，得 到隔离膜。
(4)电解液的制备
将六氟磷酸锂溶解于碳酸乙烯酯、碳酸二甲酯和碳酸甲乙酯的混合溶剂中(碳酸乙烯酯、碳酸二甲酯、碳酸甲乙酯的体积比为1：2：1，得到锂离子电池电解液。
(5)锂离子电池的制备
将上述正极片、负极片以及隔离膜进行卷绕，得到电极组件，之后经过封装、注液、化成、排气的工序，制得锂离子电池，该电池的N/P＝1，电池设计额定容量为100Ah。
实施例2
与实施例1基本相同，区别在于，步骤(2)a中，将人造石墨与胆酸钠混合，制备表面存在羧基的碳基材料，带负电荷；将Si与十二胺混合，制备表面存在氨基的硅基材料，带正电荷。
实施例3
与实施例1基本相同，区别在于，步骤(2)a中，将表面存在氨基的碳基材料和表面存在羧基的硅基材料按照质量比97：3混合，得到负极活性材料。
实施例4
与实施例1基本相同，区别在于，步骤(2)a中，将表面存在氨基的碳基材料和表面存在羧基的硅基材料按照质量比20：80混合，得到负极活性材料。
实施例5
与实施例1基本相同，区别在于，步骤(2)a中，人造石墨全部采用D50粒径为5μm的小尺寸颗粒。
实施例6
与实施例1基本相同，区别在于，步骤(2)a中，人造石墨全部采用D50粒径为25μm的大尺寸颗粒。
实施例7
与实施例1基本相同，区别在于，步骤(2)a中，Si的D50粒径为0.2μm。
实施例8
与实施例1基本相同，区别在于，步骤(2)a中，Si的D50粒径为100μm。
实施例9
与实施例1基本相同，区别在于步骤(2)a如下：
将天然石墨(按质量百分含量计，D50粒径为1μm的小尺寸颗粒占80％，D50 粒径为95μm的大尺寸颗粒占20％)和乙氧基硼酸双甘油酯照质量比100：20混合，以水作为溶剂，配制成分散液，静置2h后，固液分离保留液相，所得液相的浓度为50mg/mL的稳定水分散液；将稳定水分散液在10000rpm的转速下离心，固液分离保留固相，得到表面存在硼酸基的碳基材料，带正电荷；
将Si(D50粒径为30μm)和十二烷基苯磺酸钠按照质量比100：20混合，以水作为溶剂，配制成分散液，静置2h后，固液分离保留液相，所得液相的浓度为50mg/mL的稳定水分散液；将稳定水分散液在10000rpm的转速下离心，固液分离保留固相，得到表面存在磺酸基的硅基材料，带负电荷；
将表面存在硼酸基的碳基材料和表面存在磺酸基的硅基材料按照质量比5：95混合，得到负极活性材料。
实施例10
与实施例1基本相同，区别在于步骤(2)a如下：将硬碳(按质量百分含量计，D50粒径为5μm的小尺寸颗粒占50％，D50粒径为50μm的大尺寸颗粒占50％)和十六酰胺按照质量比100：20混合，以水作为溶剂，配制成分散液，静置2h后，固液分离保留液相，所得液相的浓度为50mg/mL的稳定水分散液；将稳定水分散液在10000rpm的转速下离心，固液分离保留固相，得到表面存在酰胺基的碳基材料，带正电荷；
将Si(D50粒径为50μm)和十六烷基溴按照质量比100：20混合，以水作为溶剂，配制成分散液，静置2h后，固液分离保留液相，所得液相的浓度为50mg/mL的稳定水分散液；将稳定水分散液在10000rpm的转速下离心，固液分离保留固相，得到表面存在溴原子的硅基材料，带负电荷；
将表面存在酰胺基的碳基材料和表面存在溴原子的硅基材料按照质量比70：30混合，得到负极活性材料。
对比例1
与实施例1基本相同，区别在于，步骤(2)a如下：
将人造石墨(按质量百分含量计，D50粒径为5μm的小尺寸颗粒占40％，D50粒径为25μm的大尺寸颗粒占60％)和Si(D50粒径为5μm)按照质量比50：50混合，得到负极活性材料。
表征测试
将上述各实施例和对比例的进行如下表征测试：
(1)容量测试
在25℃下，将二次电池以0.33C倍率恒流充电至4.3V，再恒压充电至电流为0.05C，静置5min，再以0.33C倍率恒流放电至2.5V，记录此时的放电容量，即为0.33C放电容量。
(2)倍率性能测试
在25℃下，将各实施例和对比例的二次电池以0.33C倍率恒流充电至4.3V，再恒压充电至电流为0.05C，静置5min，再以0.1C倍率恒流放电至2.5V，记录此时的放电容量，即为0.33C放电容量；静置30min，然后将二次电池以1.0C倍率恒流充电至4.3V，再恒压充电至电流为0.05C，静置5min，再以1C倍率恒流放电至2.5V，记录此时的放电容量，即为1C放电容量。
电池的倍率性能：容量保持率＝1C/0.33C(％)＝1C放电容量/0.33C放电容量×100％。
表1
Figure PCTCN2022131246-appb-000001
表2
Figure PCTCN2022131246-appb-000002
Figure PCTCN2022131246-appb-000003
表3
Figure PCTCN2022131246-appb-000004
分析表3数据，相较于实施例1，实施例2中负极活性材料的电性相反，硅基材料带正电荷、碳基材料带负电荷，由于硅的团聚较碳的团聚对电池的性能会造成更大的负面影响，特别是在高硅体系中表现尤为明显，因此，当负极活性材料中硅含量高达50％时，采用实施例1的硅负碳正方案较采用实施例2的硅正碳负方案有更大的优势，因为硅负碳正方案能有效改善硅与导电剂的团聚；实施例3中硅含量较低，虽然容量保持率较实施例1有所提升，但等条件下制得的电池0.33C容量过低；实施例4中，硅含量过高，分散较实施例1困难，虽然0.33C容量有一定的提升，但容量保持 率明显下降；实施例5中，均采用了小颗粒的碳材料，由于小颗粒缺陷多，比容量低，0.33C的容量也较实施例1有所下降；实施例6中，由于均采用了大颗粒的碳材料，会导致电池动力学恶化，各项性能均较实施例1有所下降；实施例7中，硅的颗粒较小，团聚现象加重，容量保持率下降；实施例8中，硅的颗粒较大，同样会导致动力学恶化，各项性能下降。
实施例9和10表明本申请的方案适用于不同类型的官能团。
对比例1中，碳基原料和硅基原料表面未进行表面处理，混合后团聚严重，导致容量保持率较各实施例有严重的下降，大大降低了电池的倍率性能。
以上所述实施例的各技术特征可以进行任意的组合，为使描述简洁，未对上述实施例中的各个技术特征所有可能的组合都进行描述，然而，只要这些技术特征的组合不存在矛盾，都应当认为是本说明书记载的范围。
以上所述实施例仅表达了本申请的几种实施方式，其描述较为具体和详细，但并不能因此而理解为对专利范围的限制。应当指出的是，对于本领域的普通技术人员来说，在不脱离本申请构思的前提下，还可以做出若干变形和改进，这些都属于本申请的保护范围。因此，本申请的保护范围应以所附权利要求为准。

Claims (15)

  1. 一种负极活性材料，包括碳基材料和硅基材料，所述碳基材料的表面存在第一官能团，所述硅基材料的表面存在第二官能团，所述第一官能团携带有与所述第二官能团相反的电荷。
  2. 根据权利要求1所述的负极活性材料，其特征在于，所述第一官能团携带的电荷为正电荷，所述第二官能团携带的电荷为负电荷。
  3. 根据权利要求1～2任一项所述的负极活性材料，其特征在于，所述第一官能团包括氨基、酰胺基、氰基以及硼酸基中的一种或多种。
  4. 根据权利要求1～3任一项所述的负极活性材料，其特征在于，所述第二官能团包括羧基、磺酸基、羟基以及卤素基中的一种或多种。
  5. 根据权利要求1～4任一项所述的负极活性材料，其特征在于，所述硅基材料在所述负极活性材料中的质量百分含量为1％～99％；可选地，所述硅基材料在所述负极活性材料中的质量百分含量为25％～85％。
  6. 根据权利要求1～5任一项所述的负极活性材料，其特征在于，所述碳基材料在所述负极活性材料中的质量百分含量为1％～99％；可选地，所述碳基材料在所述负极活性材料中的质量百分含量为15％～75％。
  7. 根据权利要求1～6任一项所述的负极活性材料，其特征在于，所述碳基材料包括小尺寸颗粒和大尺寸颗粒，所述小尺寸颗粒的D50粒径为0.2μm～9.9μm，所述大尺寸颗粒的D50粒径为10μm～100μm。
  8. 根据权利要求7所述的负极活性材料，其特征在于，所述小尺寸颗粒在所述负极活性材料中的质量百分含量为1％～99％，所述大尺寸颗粒在所述负极活性材料中的质量百分含量为1％～99％；可选地，所述小尺寸颗粒在所述负极活性材料中的质量百分含量为5％～75％，所述大尺寸颗粒在所述负极活性材料中的质量百分含量为25％～95％。
  9. 根据权利要求1～8任一项所述的负极活性材料，其特征在于，所述硅基材料的D50粒径为0.2μm～100μm；可选地，所述硅基材料的D50粒径为0.2μm～30μm。
  10. 根据权利要求1～9任一项所述的负极活性材料，其特征在于，所述负极活性材料满足以下(1)～(2)中的至少一个条件：
    (1)所述碳基材料的稳定水分散液的浓度为0.1mg/mL～100mg/mL；
    (2)所述硅基材料的稳定水分散液的浓度为0.1mg/mL～100mg/mL；
    其中，所述稳定水分散液是指采用水作为溶剂、配置后静置2h以上不出现沉淀的分散液经固液分离后得到的液相。
  11. 根据权利要求1～10任一项所述的负极活性材料的制备方法，包括以下步骤：
    将碳基原料、第一表面活性剂和溶剂混合，制备第一分散液，静止2h以上后进行固液分离，保留液相，得到第一稳定分散液；对所述第一稳定分散液进行离心分离处理，得到第一沉淀；所述第一沉淀经洗涤、干燥得到所述碳基材料；
    将硅基原料、第二表面活性剂和溶剂混合，制备第二分散液，静止2h以上后进行固液分离，保留液相，得到第二稳定分散液；对所述第二稳定分散液进行离心分离处理，得到第二沉淀；所述第二沉淀经洗涤、干燥得到所述硅基材料；
    将所述碳基材料和所述硅基材料混合，制备所述负极活性材料；
    其中，所述第一表面活性剂和所述第二表面活性剂在溶剂中分别携带有相反的电荷。
  12. 根据权利要求11所述的制备方法，其特征在于，所述制备方法满足以下(1)～(5)中的一个或多个条件：
    (1)所述碳基原料包括人造石墨、天然石墨、软炭以及硬炭中的一种或多种；
    (2)所述硅基原料包括Si以及SiO x(0<x<2)中的一种或多种；
    (3)所述第一表面活性剂和第二表面活性剂分别独立地选自以下的一种或多种：十二胺、十六酰胺、十二腈、乙氧基硼酸双甘油酯、胆酸钠、十二烷基苯磺酸钠、癸炔二醇以及十六烷基溴；
    (4)所述第一表面活性剂的用量为所述碳基原料质量的0.1％～40％；
    (5)所述第二表面活性剂的用量为所述硅基原料质量的0.1％～40％。
  13. 一种二次电池，包括正极极片、负极极片和隔离膜，所述隔离膜设置于所述正极极片和所述负极极片之间；
    其中，所述负极极片包括负极集流体和设置于所述负极集流体至少一个表面的负极活性材料层，所述负极活性材料层包括权利要求1～10任一项所述的负极活性材料。
  14. 一种二次电池的制备方法，包括以下步骤：
    提供正极集流体，在所述正极集流体表面涂覆正极浆料，干燥、压制，得到正极极片；
    提供负极集流体，在所述负极集流体表面涂覆负极浆料，干燥、压制，得到负极极片；其中，所述负极浆料包括权利要求1～10任一项所述的负极活性材料；可选地， 所述负极浆料的固含量为30％～70％；
    将所述正极极片、隔离膜以及所述负极极片进行层叠或卷绕，制备所述二次电池。
  15. 一种用电装置，包括权利要求13所述的二次电池或权利要求14所述的制备方法制得的二次电池。
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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20140130578A (ko) * 2013-05-01 2014-11-11 한국과학기술원 나노섬유와 그래핀의 복합체를 이용한 리튬-이온 이차전지용 음극활물질 및 그 제조 방법
CN104868095A (zh) * 2014-02-25 2015-08-26 江门市荣炭电子材料有限公司 碳硅复合电极材料及其制备方法
CN106415894A (zh) * 2014-01-30 2017-02-15 罗伯特·博世有限公司 缩合的硅-碳-复合材料
CN110571425A (zh) * 2019-09-24 2019-12-13 中国科学院化学研究所 一种低膨胀率硅碳复合材料及其制备方法
CN112164780A (zh) * 2020-09-29 2021-01-01 Oppo广东移动通信有限公司 硅基负极材料及其制备方法、及相关产品
CN112889165A (zh) * 2018-11-22 2021-06-01 国立大学法人信州大学 二次电池用负极活性物质及其制造方法和二次电池

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20140130578A (ko) * 2013-05-01 2014-11-11 한국과학기술원 나노섬유와 그래핀의 복합체를 이용한 리튬-이온 이차전지용 음극활물질 및 그 제조 방법
CN106415894A (zh) * 2014-01-30 2017-02-15 罗伯特·博世有限公司 缩合的硅-碳-复合材料
CN104868095A (zh) * 2014-02-25 2015-08-26 江门市荣炭电子材料有限公司 碳硅复合电极材料及其制备方法
CN112889165A (zh) * 2018-11-22 2021-06-01 国立大学法人信州大学 二次电池用负极活性物质及其制造方法和二次电池
CN110571425A (zh) * 2019-09-24 2019-12-13 中国科学院化学研究所 一种低膨胀率硅碳复合材料及其制备方法
CN112164780A (zh) * 2020-09-29 2021-01-01 Oppo广东移动通信有限公司 硅基负极材料及其制备方法、及相关产品

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