WO2023124315A1 - 一种电化学装置和电子装置 - Google Patents

一种电化学装置和电子装置 Download PDF

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WO2023124315A1
WO2023124315A1 PCT/CN2022/121787 CN2022121787W WO2023124315A1 WO 2023124315 A1 WO2023124315 A1 WO 2023124315A1 CN 2022121787 W CN2022121787 W CN 2022121787W WO 2023124315 A1 WO2023124315 A1 WO 2023124315A1
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silicon
electrochemical device
composite material
negative electrode
carbon composite
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PCT/CN2022/121787
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English (en)
French (fr)
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李亮
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东莞新能源科技有限公司
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Publication of WO2023124315A1 publication Critical patent/WO2023124315A1/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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • 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
    • H01M4/362—Composites
    • 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
    • H01M4/386—Silicon or alloys based on silicon
    • 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 electrochemical technology, in particular to an electrochemical device and an electronic device.
  • Lithium-ion batteries have the advantages of high energy storage density, high open circuit voltage, low self-discharge rate, long cycle life, and good safety. They are widely used in various fields such as portable electric energy storage, electronic equipment, and electric vehicles. In the process of rapid development of lithium-ion batteries, higher requirements are put forward for the comprehensive performance of lithium-ion batteries, such as high energy density and good cycle performance at the same time.
  • Silicon materials have a high gram capacity (up to 4200mAh/g), and being used as negative electrode active materials for lithium-ion batteries can significantly increase the energy density of lithium-ion batteries.
  • the silicon material will have a large volume expansion, specifically, its volume can increase to 300% to 400% of the original volume, so the problem of cracking or pulverization of the silicon material is prone to occur, and then This leads to pulverization of the negative electrode material layer in the negative electrode sheet, affects the formation of the solid electrolyte interface (SEI) film, and reduces the cycle performance of the lithium-ion battery.
  • SEI solid electrolyte interface
  • the purpose of the present application is to provide an electrochemical device and an electronic device to improve the cycle performance of the electrochemical device.
  • the first aspect of the present application provides an electrochemical device, which includes a negative electrode sheet, the negative electrode sheet includes a negative electrode material layer, the negative electrode material layer includes a silicon-carbon composite material, and the silicon-carbon composite material includes porous carbon Skeleton and silicon material, the average particle size of the silicon-carbon composite material is a ⁇ m, satisfying 3 ⁇ a ⁇ 15, the porosity of the negative electrode material layer is b%, and the electrochemical device satisfies 0.15 ⁇ a/b ⁇ 1 .
  • the porous carbon skeleton has a porous structure, which can provide expansion space for the silicon material in the silicon-carbon composite material to buffer the expansion stress generated during the expansion process, and at the same time regulate the average particle size of the silicon-carbon composite material and the average particle size of the silicon-carbon composite material
  • the ratio to the porosity of the negative electrode material layer is within the above range, which can not only provide enough space for the volume expansion of the silicon material in the silicon-carbon composite material, but also make the particles of the silicon-carbon composite material have good electrical contact. , thereby improving the cycle performance and expansion performance of the electrochemical device, and enabling the electrochemical device to have good rate performance.
  • the porosity b% of the negative electrode material layer satisfies 15 ⁇ b ⁇ 35.
  • the compacted density of the negative electrode material layer is 1.2 g/cm 3 to 1.8 g/cm 3 .
  • the mass percentage of carbon in the silicon-carbon composite material is d%, which satisfies 15 ⁇ d ⁇ 75, and the silicon-carbon composite material
  • the mass percentage of silicon is e%, satisfying 15 ⁇ e ⁇ 75
  • the mass percentage of oxygen in the silicon-carbon composite material is 0.3% to 10%.
  • the pore volume of the porous carbon framework is 0.5ml/g to 2.0ml/g, based on the pore volume of the porous carbon framework, the pore volume percentage of micropores and mesopores is 70% to 90%.
  • the porous carbon skeleton has a large number of micropores and mesopores.
  • the silicon material in the silicon-carbon composite material is distributed in the micropore and mesopore structure, which provides expansion space for the silicon material in the silicon-carbon composite material and can buffer the expansion process. The expansion stress, thereby improving the cycle performance and expansion performance of the electrochemical device.
  • the electrochemical device includes an electrolyte, the electrolyte includes ethylene carbonate, based on the total mass of the electrolyte, the mass percentage of the ethylene carbonate is f%, Satisfy 5 ⁇ f ⁇ 30.
  • the electrochemical device satisfies 0.2 ⁇ a/f ⁇ 2.
  • a/f the value of a/f within the above range, it is beneficial to form a synergistic effect between the silicon-carbon composite material and ethylene carbonate in the electrolyte to improve the cycle performance, expansion performance and rate performance of the electrochemical device.
  • the electrolytic solution includes propylene carbonate, and based on the total mass of the electrolytic solution, the mass percentage of the propylene carbonate is g%, satisfying 5 ⁇ g ⁇ 40.
  • the preparation method of the silicon-carbon composite material includes the following steps: (1) placing the porous carbon skeleton in a silane atmosphere to perform the first deposition reaction, wherein the pore volume of the porous carbon skeleton 0.5ml/g to 2.0ml/g, based on the pore volume of the porous carbon skeleton, the pore volume percentage of micropores and mesopores is 70% to 90%; the volume percentage of silane in the silane atmosphere is 1% to 30%, the temperature of the first deposition reaction is 400°C to 600°C, and the time is 1h to 12h; (2) Then carry out the second deposition reaction in an oxygen atmosphere to obtain a silicon-carbon composite material, wherein, in the oxygen atmosphere The volume percentage of oxygen is 1% to 30%, the temperature of the second deposition reaction is 400°C to 800°C, and the time is 1h to 12h.
  • the silicon-carbon composite material prepared by the preparation method provided by this application can not only take advantage of the high specific capacity of the silicon material to improve the specific capacity of the electrochemical device, but also
  • the porous carbon framework provides enough space for the volume expansion of silicon materials to relieve the expansion stress caused by volume expansion, which is beneficial to improve the cycle performance and expansion performance of electrochemical devices.
  • a second aspect of the present application provides an electronic device, which includes the electrochemical device in any one of the foregoing embodiments.
  • the electrochemical device provided by the application has good cycle performance, expansion performance and rate performance, so the electronic device provided by the application has a long service life.
  • the application provides an electrochemical device and an electronic device.
  • the electrochemical device includes a negative electrode sheet, the negative electrode sheet includes a negative electrode material layer, the negative electrode material layer includes a silicon-carbon composite material, and the silicon-carbon composite material includes a porous carbon skeleton and a silicon material.
  • the average particle size of the carbon composite material is a ⁇ m, which satisfies 3 ⁇ a ⁇ 15, the porosity of the negative electrode material layer is b%, and the electrochemical device satisfies 0.15 ⁇ a/b ⁇ 1.
  • the porous carbon skeleton has a porous structure, which can provide expansion space for the silicon material in the silicon-carbon composite material to buffer the expansion stress generated during the expansion process, and at the same time regulate the average particle size of the silicon-carbon composite material and the average particle size of the silicon-carbon composite material
  • the ratio to the porosity of the negative electrode material layer is within the above range, which can not only provide enough space for the volume expansion of the silicon material in the silicon-carbon composite material, but also make the particles of the silicon-carbon composite material have good electrical contact. , thereby improving the cycle performance and expansion performance of the electrochemical device, and enabling the electrochemical device to have good rate performance.
  • the lithium-ion battery is used as an example of the electrochemical device to explain the present application, but the electrochemical device of the present application is not limited to the lithium-ion battery.
  • the first aspect of the present application provides an electrochemical device, which includes a negative electrode sheet, the negative electrode sheet includes a negative electrode material layer, the negative electrode material layer includes a silicon-carbon composite material, the silicon-carbon composite material includes a porous carbon skeleton and a silicon material, silicon
  • the average particle size of the carbon composite material is a ⁇ m, satisfying 3 ⁇ a ⁇ 15, preferably 6 ⁇ a ⁇ 12, the porosity of the negative electrode material layer is b%, and the electrochemical device satisfies 0.15 ⁇ a/b ⁇ 1, preferably 0.3 ⁇ a /b ⁇ 1.
  • the average particle size of the silicon-carbon composite material can be 3 ⁇ m, 4 ⁇ m, 5 ⁇ m, 6 ⁇ m, 7 ⁇ m, 8 ⁇ m, 9 ⁇ m, 10 ⁇ m, 11 ⁇ m, 12 ⁇ m, 13 ⁇ m, 14 ⁇ m, 15 ⁇ m or any range in between, and the value of a/b can be 0.15, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1 or any range therebetween.
  • the inventors of the present application found that when the average particle size of the silicon-carbon composite material is too small (for example, less than 3 ⁇ m), the specific surface area of the silicon-carbon composite material increases, and side reactions with the electrolyte are likely to occur, thereby affecting the cycle performance of the electrochemical device .
  • the average particle size of the silicon-carbon composite material is too large (for example, greater than 15 ⁇ m), it is difficult to provide enough space for the volume expansion of the silicon material in the silicon-carbon composite material, and it is impossible to effectively buffer the expansion stress generated during the expansion process, thereby affecting electrical properties. Cycling performance and rate performance of chemical devices.
  • the porous carbon skeleton has a porous structure, which can provide expansion space for the silicon material in the silicon-carbon composite material to buffer the expansion stress generated during the expansion process.
  • the porosity of the negative electrode material layer is b%, satisfying 15 ⁇ b ⁇ 35, preferably 18 ⁇ b ⁇ 30, for example, the porosity of the negative electrode material layer can be 15%, 20% , 25%, 30%, 35%, or any range therebetween.
  • the porosity of the negative electrode material layer is too small (for example, less than 15%), it cannot provide enough space for the volume expansion of the silicon material in the silicon-carbon composite material, which will affect the cycle performance and expansion performance of the electrochemical device.
  • the porosity of the negative electrode material layer is too large (for example greater than 35%), the electrical contact between particles of the silicon-carbon composite material will be reduced, which will affect the rate performance of the electrochemical device.
  • the porosity of the negative electrode material layer refers to the percentage of the volume of pores in the negative electrode material layer to the volume of the negative electrode material layer.
  • the compacted density of the negative electrode material layer is 1.2 g/cm 3 to 1.8 g/cm 3 , preferably 1.4 g/cm 3 to 1.8 g/cm 3 .
  • the compacted density of the negative electrode material layer can be 1.2g/cm 3 , 1.3g/cm 3 , 1.4g/cm 3 , 1.5g/cm 3 , 1.6g/cm 3 , 1.7g/cm 3 , 1.8g/cm 3 , 1.8g/cm 3 cm 3 or any range in between.
  • the compaction density of the negative electrode material layer is too small (for example, less than 1.2g/cm 3 ), the porosity of the negative electrode material layer increases, and the electrical contact between the particles of the silicon-carbon composite material decreases, which will affect the electrochemical device. rate performance.
  • the compacted density of the negative electrode material layer is too large (for example, greater than 1.8g/cm 3 ), the porosity of the negative electrode material layer decreases, and it cannot provide enough space for the volume expansion of the silicon material to release the expansion stress generated during the expansion process. , will affect the cycle performance and expansion performance of the electrochemical device.
  • By adjusting the compaction density of the negative electrode material layer within the above range it is beneficial to improve the cycle performance and expansion performance of the electrochemical device, and to make the electrochemical device have good rate performance.
  • the mass percentage of carbon in the silicon-carbon composite material is d%, which satisfies 15 ⁇ d ⁇ 75, preferably 40 ⁇ d ⁇ 75, and the silicon-carbon composite
  • the mass percentage of silicon in the material is e%, which satisfies 15 ⁇ e ⁇ 75, preferably 40 ⁇ e ⁇ 75
  • the mass percentage of oxygen in the silicon-carbon composite material is 0.3% to 10%, preferably 1% to 6%.
  • the mass percentage of carbon in the silicon-carbon composite material can be 15%, 20%, 30%, 40%, 50%, 60%, 70%, 75%, or any range therebetween.
  • the mass percentage content of silicon can be 15%, 20%, 30%, 40%, 50%, 60%, 70%, 75% or any range therebetween, and the mass percentage content of oxygen in the silicon-carbon composite material can be 0.3%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or any range therebetween. It can be understood that there may be a small amount (less than 0.1% by mass) of impurities in the silicon-carbon composite material. For the convenience of discussion, this application ignores the impurities, that is, the mass of silicon, carbon and oxygen in the silicon-carbon composite material The sum of the percentages is 100%.
  • the inventors of the present application have found that when the mass percentage of carbon in the silicon-carbon composite material is too low (for example, less than 15%), it cannot provide enough expansion space for the silicon material in the silicon-carbon composite material, thereby affecting the electrochemical performance.
  • the cycle performance and expansion performance of the device When the mass percentage of carbon in the silicon-carbon composite material is too high (for example, higher than 75%), the mass percentage of silicon is low at this time, and the high gram capacity advantage of the silicon material in the silicon-carbon composite material cannot be effectively utilized. , will affect the specific capacity of the battery.
  • By adjusting the mass percentage of carbon in the silicon-carbon composite material within the above range it is beneficial to improve the cycle performance and expansion performance of the electrochemical device, and to make the electrochemical device have a higher specific capacity.
  • the mass percentage of silicon in the silicon-carbon composite material is too low (for example, less than 15%), it will affect the first-cycle reversible capacity of the electrochemical device, and the high gram capacity of the silicon material in the silicon-carbon composite material cannot be effectively utilized. Advantages will affect the specific capacity of the battery.
  • the mass percent content of silicon in the silicon-carbon composite material is too high (for example, higher than 75%), the mass percent content of carbon is low at this time, which cannot provide enough expansion space for the silicon material in the silicon-carbon composite material , which will affect the cycle performance and expansion performance of the electrochemical device; in addition, too high a mass percentage of silicon is not conducive to the transmission of lithium ions and electrons, thereby affecting the rate performance of the electrochemical device.
  • Oxygen in the silicon-carbon composite material will form an inert layer with lithium ions on the surface of the silicon-carbon composite material, which can improve the expansion performance of the silicon material in the silicon-carbon composite material, thereby improving the cycle performance and expansion performance of the electrochemical device.
  • the mass percentage of oxygen in the silicon-carbon composite material is too high (for example, higher than 10%)
  • the formed inert layer will affect the transport of lithium ions, thereby affecting the rate performance and first cycle coulombic efficiency of the electrochemical device.
  • the silicon-carbon composite material satisfies 0.5 ⁇ d/e ⁇ 5, preferably 0.8 ⁇ d/e ⁇ 3.
  • the value of d/e can be 0.5, 1, 2, 3, 4, 5 or any range in between.
  • the pore volume of the porous carbon skeleton is 0.5ml/g to 2.0ml/g, preferably 0.8ml/g to 2.0ml/g, based on the pore volume of the porous carbon skeleton, micropores and mesopores
  • the pore volume percentage of the pores is 70% to 90%, preferably 80% to 90%.
  • the pore volume of the porous carbon skeleton can be 0.5ml/g, 0.6ml/g, 0.7ml/g, 0.8ml/g, 0.9ml/g, 1.0ml/g, 1.1ml/g, 1.2ml/g, 1.3ml/g, 1.5ml/g, 1.8ml/g, 2.0ml/g or any range in between, the pore volume percentage of micropores and mesopores is 70%, 75%, 80%, 85%, 90% or any range in between.
  • the porous carbon skeleton has a large number of micropores and mesopores.
  • the silicon material in the silicon-carbon composite material is distributed in the micropore and mesopore structure, which provides expansion space for the silicon material in the silicon-carbon composite material and can buffer the expansion process.
  • the expansion stress thereby improving the cycle performance and expansion performance of the electrochemical device.
  • the pore volume percentage of micropores and mesopores refers to the percentage of the ratio of the sum of the pore volumes of micropores and mesopores to the pore volume of the porous carbon framework. Pores between 2nm and 50nm.
  • the electrochemical device includes an electrolyte, and the electrolyte includes ethylene carbonate (EC), based on the total mass of the electrolyte, the mass percentage of ethylene carbonate is f%, satisfying 5 ⁇ f ⁇ 30, preferably 10 ⁇ f ⁇ 30.
  • the mass percentage of EC may be 5%, 10%, 15%, 20%, 25%, 30% or any range therebetween.
  • the mass percentage of EC is too high (for example, higher than 30%), the viscosity of the electrolyte increases, which is not conducive to the transmission of lithium ions, the conductivity of the electrolyte decreases, and EC will intercalate with lithium ions into the silicon-carbon composite. In the material, the reversible capacity is reduced, thereby affecting the rate performance, cycle performance and capacity of the electrochemical device.
  • the mass percentage of EC within the above range, it is beneficial to improve the cycle performance and rate performance of the electrochemical device.
  • the electrochemical device satisfies 0.2 ⁇ a/f ⁇ 2, preferably 0.2 ⁇ a/f ⁇ 1.5.
  • the value of a/f can be 0.2, 0.4, 0.6, 0.8, 1, 1.2, 1.5, 2 or any range therebetween.
  • the value of a/f is too small (for example, less than 0.2), that is, the average particle size of the silicon-carbon composite material is small or the mass percentage of EC is high, the rate performance of the electrochemical device will be affected.
  • a/f When the value of a/f is too large (such as greater than 2), that is, the average particle size of the silicon-carbon composite material is large or the mass percentage of EC is low, it will affect the cycle performance, expansion performance and rate of the electrochemical device. performance.
  • a/f By adjusting the value of a/f within the above range, it is beneficial to form a synergistic effect between the silicon-carbon composite material and the EC in the electrolyte to improve the cycle performance, expansion performance and rate performance of the electrochemical device.
  • the electrolyte includes propylene carbonate (PC), based on the total mass of the electrolyte, the mass percentage of propylene carbonate is g%, satisfying 5 ⁇ g ⁇ 40, preferably 10 ⁇ g ⁇ 30.
  • the mass percentage of PC can be 5%, 10%, 20%, 30%, 40% or any range therebetween.
  • the preparation method of the silicon-carbon composite material comprises the following steps: (1) placing the porous carbon skeleton in a silane atmosphere for the first deposition reaction, wherein the porous carbon skeleton has a pore volume of 0.5ml/ g to 2.0ml/g, based on the pore volume of the porous carbon skeleton, the pore volume percentage of micropores and mesopores is 70% to 90%; the volume percentage of silane in a silane atmosphere is 1% to 30%, the first deposition reaction The temperature is from 400°C to 600°C, and the time is from 1h to 12h; (2) performing a second deposition reaction in an oxygen atmosphere to obtain a silicon-carbon composite material, wherein the volume percentage of oxygen in the oxygen atmosphere is 1% to 30%.
  • the temperature of the secondary deposition reaction is 400°C to 800°C, and the time is 1h to 12h.
  • the silicon material is embedded in the micropores and mesopores of the porous carbon framework, which can not only take advantage of the high gram capacity of the silicon material to improve the specific capacity of the electrochemical device, but also the porous carbon framework It provides enough space for the volume expansion of the silicon material to relieve the expansion stress caused by the volume expansion, which is beneficial to improve the cycle performance and expansion performance of the electrochemical device.
  • the above-mentioned siloxane atmosphere and oxygen atmosphere further include an inert gas, and the inert gas may include but not limited to at least one of nitrogen, argon or helium.
  • the average particle size of the silicon-carbon composite material can be adjusted by adjusting the average particle size of the porous carbon skeleton.
  • increasing the average particle size of the porous carbon skeleton increases the average particle size of the silicon-carbon composite material; decreasing the average particle size of the porous carbon skeleton reduces the average particle size of the silicon-carbon composite material.
  • the present application has no particular limitation on the average particle size of the porous carbon skeleton, as long as the average particle size of the aforementioned silicon-carbon composite material can be met, for example, the average particle size of the porous carbon skeleton is 1 ⁇ m to 20 ⁇ m.
  • the temperature and time of the first deposition reaction and the second deposition reaction generally affect the performance of the silicon-carbon composite material.
  • increasing the temperature of the first deposition reaction can increase the degree of crystallization of the silicon material, which is beneficial to improving the first-cycle Coulombic efficiency of the electrochemical device, but it will affect its expansion performance;
  • increasing the temperature of the second deposition reaction can increase the degree of silicon crystallization.
  • the thickness of the passivation layer on the surface of the material can be improved, thereby improving the processing stability of the silicon-carbon composite material; prolonging the time of the first deposition reaction is conducive to increasing the silicon content of the silicon-carbon composite material and improving the specific capacity of the electrochemical device.
  • a high silicon content will affect the expansion performance of the electrochemical device; prolonging the time of the second deposition reaction can increase the thickness of the passivation layer on the surface of the silicon material and improve the processing stability of the silicon-carbon composite material; reducing the temperature of the first deposition reaction will Reducing the degree of crystallization of the silicon material will affect the performance of the Coulombic efficiency of the first cycle of the electrochemical device; reducing the temperature of the second deposition reaction is not conducive to the formation of a stable passivation layer on the surface of the silicon material; shortening the time of the first deposition reaction, the silicon content will be corresponding Reducing, an appropriate amount of silicon content is conducive to improving the cycle performance and expansion performance of the electrochemical device; shortening the time of the second deposition reaction will affect the thickness of the stable passivation layer formed on the surface of the silicon material.
  • the porous carbon skeleton may include but not limited to at least one of natural graphite, artificial graphite, mesophase microcarbon spheres, hard carbon or soft carbon
  • the silicon material may include but not limited to crystalline silicon or amorphous silicon. at least one.
  • the negative electrode sheet also includes a negative electrode collector.
  • This application has no special restrictions on the negative electrode collector, as long as the purpose of this application can be achieved.
  • it can include but is not limited to copper foil, copper alloy foil, nickel foil, stainless steel Foil, titanium foil, nickel foam, copper foam or composite current collector, etc.
  • the negative electrode material layer may be provided on one surface or both surfaces along the thickness direction of the negative electrode current collector. It should be noted that the "surface" here may be the entire area of the negative electrode collector, or a partial area of the negative electrode collector.
  • This application is not particularly limited, as long as the purpose of this application can be achieved.
  • there is no particular limitation on the thickness of the current collector of the negative electrode as long as the purpose of the present application can be achieved, for example, the thickness is 4 ⁇ m to 12 ⁇ m.
  • the anode material layer may include other anode active materials known in the art in addition to the above-mentioned silicon-carbon composite material, for example, may include but not limited to natural graphite, artificial graphite, mesophase microcarbon spheres, hard Carbon, soft carbon, silicon, silicon-carbon composite, Li-Sn alloy, Li-Sn-O alloy, Sn, SnO, SnO 2 , lithiated TiO 2 -Li 4 Ti 5 O 12 or Li with spinel structure - at least one of Al alloys.
  • the negative electrode material layer may also include a negative electrode conductive agent.
  • This application has no special restrictions on the negative electrode conductive agent, as long as the purpose of this application can be achieved, for example, it may include but not limited to carbon-based materials, metal-based materials or at least one of conductive polymers.
  • the above-mentioned carbon-based material is at least one selected from natural graphite, artificial graphite, conductive carbon black, acetylene black, Ketjen black or carbon fiber.
  • the above-mentioned metal-based material may include but not limited to metal powder and/or metal fiber, specifically, the metal may include but not limited to at least one of copper, nickel, aluminum or silver.
  • the conductive polymer may include, but is not limited to, at least one of polyphenylene derivatives, polyaniline, polythiophene, polyacetylene, or polypyrrole.
  • the negative electrode material layer may also include a negative electrode binder.
  • the present application has no special restrictions on the negative electrode binder, as long as the purpose of the application can be achieved, for example, it may include but not limited to polyvinyl alcohol, carboxymethyl Cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, At least one of polyvinylidene fluoride, polyethylene, polypropylene, polyacrylic acid, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin or nylon.
  • the negative electrode sheet may further include a conductive layer located between the negative electrode current collector and the negative electrode material layer.
  • the present application has no particular limitation on the composition of the conductive layer, which may be a commonly used conductive layer in the field, and the conductive layer may include but not limited to the above-mentioned negative electrode conductive agent and the above-mentioned negative electrode binder.
  • the electrolyte solution of this application also includes lithium salts and other non-aqueous solvents.
  • This application has no special restrictions on lithium salts, as long as the purpose of this application can be achieved, for example, it can include but not limited to LiPF 6 , LiBF 4 , LiAsF 6 , LiClO 4. LiB(C 6 H 5 ) 4 , LiCH 3 SO 3 , LiCF 3 SO 3 , LiN(SO 2 CF 3 ) 2 , LiC(SO 2 CF 3 ) 3 , LiSiF 6 , LiBOB or lithium difluoroborate at least one.
  • the lithium salt comprises LiPF 6 .
  • the present application has no special restrictions on other non-aqueous solvents, as long as the purpose of the present application can be achieved, for example, it may include but not limited to at least one of carbonate compounds, carboxylate compounds, ether compounds or other organic solvents.
  • the above-mentioned carbonate compound may include but not limited to at least one of chain carbonate compound, cyclic carbonate compound or fluorocarbonate compound.
  • Above-mentioned chain carbonate compound can include but not limited to dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethylene propyl carbonate (EPC) or at least one of methyl ethyl carbonate (MEC).
  • the aforementioned cyclic carbonate may include, but is not limited to, at least one of butylene carbonate (BC) or vinylethylene carbonate (VEC).
  • Fluorocarbonate compounds may include, but are not limited to, fluoroethylene carbonate (FEC), 1,2-difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate Ethylene carbonate, 1,1,2,2-tetrafluoroethylene carbonate, 1-fluoro-2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2- At least one of difluoro-1-methylethylene carbonate, 1,1,2-trifluoro-2-methylethylene carbonate, or trifluoromethylethylene carbonate.
  • FEC fluoroethylene carbonate
  • 1,2-difluoroethylene carbonate 1,1-difluoroethylene carbonate
  • 1,1,2,2-tetrafluoroethylene carbonate 1,1,2,2-te
  • carboxylate compounds may include but are not limited to methyl formate, methyl acetate, ethyl acetate, n-propyl acetate, tert-butyl acetate, methyl propionate, ethyl propionate, propyl propionate, ⁇ -butyl At least one of lactone, decanolactone, valerolactone or caprolactone.
  • the aforementioned ether compounds may include, but are not limited to, dibutyl ether, tetraglyme, diglyme, 1,2-dimethoxyethane, 1,2-diethoxyethane, 1- At least one of ethoxy-1-methoxyethane, 2-methyltetrahydrofuran or tetrahydrofuran.
  • the above-mentioned other organic solvents may include but not limited to dimethyl sulfoxide, 1,2-dioxolane, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, N-methyl-2- At least one of pyrrolidone, dimethylformamide, acetonitrile, trimethyl phosphate, triethyl phosphate or trioctyl phosphate.
  • the above-mentioned other non-aqueous solvents have a mass percentage of 17% to 83%, such as 17%, 17.5%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 82.5%, 83%, or any range therebetween.
  • the electrochemical device of the present application may also include a positive pole piece.
  • the present application has no special limitation on the positive pole piece, as long as the purpose of the application can be achieved.
  • the positive pole piece usually includes a positive electrode current collector and a positive electrode material layer.
  • the positive electrode material layer may be provided on one surface in the thickness direction of the positive electrode current collector, or on both surfaces in the thickness direction of the positive electrode current collector. It should be noted that the "surface” here may refer to the entire area of the positive electrode collector or a partial area of the positive electrode collector. This application is not particularly limited, as long as the purpose of this application can be achieved.
  • the positive electrode current collector is not particularly limited, as long as the purpose of the present application can be achieved, for example, it may include but not limited to aluminum foil, aluminum alloy foil, or a composite current collector.
  • the thickness of the positive electrode collector there is no particular limitation on the thickness of the positive electrode collector, as long as the purpose of the present application can be achieved, for example, the thickness is 8 ⁇ m to 12 ⁇ m.
  • the positive electrode material layer includes the positive electrode active material, and the present application has no special limitation on the positive electrode active material, as long as the purpose of the application can be achieved, for example, at least one of the composite oxides of lithium or transition metal elements can be included .
  • the present application has no particular limitation on the above transition metal elements, as long as the purpose of the present application can be achieved, for example, at least one of nickel, manganese, cobalt or iron may be included.
  • the positive electrode active material may include at least one of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminate, lithium iron phosphate, lithium-rich manganese-based materials, lithium cobalt oxide, lithium manganate, lithium manganese iron phosphate, or lithium titanate. kind.
  • the positive electrode material layer may also include a positive electrode conductive agent, and the present application has no special restrictions on the positive electrode conductive agent, as long as the purpose of the application can be achieved, for example, it may include but not limited to conductive carbon black (Super P), carbon At least one of nanotubes (CNTs), carbon fibers, acetylene black, flake graphite, Ketjen black, graphene, metal materials or conductive polymers.
  • the positive electrode conductive agent includes conductive carbon black and carbon nanotubes.
  • the aforementioned carbon nanotubes may include, but are not limited to, single-walled carbon nanotubes and/or multi-walled carbon nanotubes.
  • the aforementioned carbon fibers may include, but are not limited to, vapor grown carbon fibers (VGCF) and/or carbon nanofibers.
  • the above metal material may include but not limited to metal powder and/or metal fiber, specifically, the metal may include but not limited to at least one of copper, nickel, aluminum or silver.
  • the aforementioned conductive polymer may include but not limited to at least one of polyphenylene derivatives, polyaniline, polythiophene, polyacetylene or polypyrrole.
  • the positive electrode material layer may also include a positive electrode binder. This application has no special restrictions on the positive electrode binder, as long as the purpose of this application can be achieved. For example, it may include but not limited to fluorine-containing resin, polypropylene resin, At least one of fiber type adhesive, rubber type adhesive or polyimide type adhesive.
  • the positive electrode sheet may further include a conductive layer located between the positive electrode current collector and the positive electrode material layer.
  • the present application has no particular limitation on the composition of the conductive layer, which may be a commonly used conductive layer in the field, for example, may include but not limited to the above-mentioned positive electrode conductive agent and the above-mentioned positive electrode binder.
  • the electrochemical device of the present application may also include a separator, and the present application has no particular limitation on the separator, as long as the purpose of the present application can be achieved.
  • the above-mentioned isolation film may include a substrate layer and a surface treatment layer.
  • the present application has no special limitation on the material of the substrate layer, for example, it may include but not limited to polyethylene, polypropylene, polytetrafluoroethylene-based polyolefin, polyester film (such as polyethylene terephthalate), cellulose, polyimide, polyamide, spandex, aramid; the type of substrate layer may include but not limited to woven film, non-woven film, At least one of microporous membrane, composite membrane, separator paper, rolling membrane or spun membrane, the material of the substrate layer is preferably polyethylene or polypropylene, which have a good effect on preventing short circuit and can be shut off effect improves the stability of the electrochemical device.
  • the separator of the present application may have a porous structure, and the pore size is not particularly limited as long as the purpose of the present application can be achieved, for example, the pore size may be 0.01 ⁇ m to 1 ⁇ m.
  • the thickness of the isolation film is not particularly limited, as long as the purpose of the present application can be achieved, for example, the thickness may be 5 ⁇ m to 500 ⁇ m.
  • At least one surface of the substrate layer is provided with a surface treatment layer.
  • the application has no special limitation on the surface treatment layer. It can be a polymer layer or an inorganic layer, or a layer made of a mixed polymer and an inorganic material. formed layer.
  • the inorganic material layer may include but not limited to inorganic particles and inorganic material layer binder, and the present application has no special limitation on inorganic particles, for example, may include but not limited to aluminum oxide, silicon oxide, magnesium oxide, titanium oxide, hafnium dioxide, At least one of tin oxide, cerium oxide, nickel oxide, zinc oxide, calcium oxide, zirconium oxide, yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide or barium sulfate.
  • the present application has no particular limitation on the inorganic layer binder, for example, it may include but not limited to polyvinylidene fluoride, copolymer of vinylidene fluoride-hexafluoropropylene, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, At least one of polyacrylate, polyvinylpyrrolidone, polyvinyl ether, polymethylmethacrylate, polytetrafluoroethylene or polyhexafluoropropylene.
  • polyvinylidene fluoride copolymer of vinylidene fluoride-hexafluoropropylene
  • polyamide polyacrylonitrile
  • polyacrylate polyacrylic acid
  • Polymers are contained in the polymer layer, and the present application has no special limitation on polymers, and the materials of polymers may include but not limited to polyamide, polyacrylonitrile, acrylate polymer, polyacrylic acid, polyacrylate, polyvinylpyrrolidine At least one of ketone, polyvinyl ether, polyvinylidene fluoride or poly(vinylidene fluoride-hexafluoropropylene).
  • electrochemical device of the present application is not particularly limited, and it may include any device that undergoes an electrochemical reaction.
  • electrochemical devices may include, but are not limited to, lithium-ion batteries.
  • the preparation process of electrochemical devices is well known to those skilled in the art, and the present application is not particularly limited.
  • it may include but not limited to the following steps: stack the positive electrode sheet, separator and negative electrode sheet in sequence, and as required Winding, folding and other operations to obtain the electrode assembly with a winding structure, put the electrode assembly into the packaging bag, inject the electrolyte into the packaging bag and seal it, and obtain an electrochemical device; or, put the positive electrode sheet, separator and negative electrode
  • the pole pieces are stacked in order, and then the four corners of the entire laminated structure are fixed with adhesive tape to obtain the electrode assembly of the laminated structure.
  • the electrode assembly is placed in the packaging bag, and the electrolyte is injected into the packaging bag and sealed to obtain an electrochemical device.
  • overcurrent prevention elements, guide plates, etc. can also be placed in the packaging bag as needed, so as to prevent pressure rise and overcharge and discharge inside the electrochemical device.
  • a second aspect of the present application provides an electronic device, which includes the electrochemical device in any one of the foregoing embodiments.
  • the electrochemical device provided by the application has good cycle performance, expansion performance and rate performance, so the electronic device provided by the application has a long service life.
  • the electronic device of the present application is not particularly limited, and it may be used in any electronic device known in the prior art.
  • electronic devices may include, but are not limited to, notebook computers, pen-based computers, mobile computers, e-book players, cellular phones, portable fax machines, portable copiers, portable printers, headsets, VCRs, LCD TVs, portable cleaners, portable CD players, mini discs, transceivers, electronic organizers, calculators, memory cards, portable tape recorders, radios, backup power supplies, motors, cars, motorcycles, power-assisted bicycles, bicycles, Lighting appliances, toys, game consoles, clocks, electric tools, flashlights, cameras, large household storage batteries and lithium-ion capacitors, etc.
  • the average particle size of the composite material is defined as follows to test and characterize the average particle size of the silicon-carbon composite material in the negative electrode sheet: in conjunction with the scanning electron microscope test method, use the scanning electron microscope (ZEISS Sigma-02-33) equipment in the back-scattering mode In the lower case (0.1KV to 30KV), at a magnification of 100K, the particles with the lightest color in terms of color contrast are the particles corresponding to the silicon-carbon composite material, and the value of the longest distance between two points existing in each of the above particles is taken as For the particle size of the particles, count the particle sizes of all silicon-carbon composite materials at the 100K magnification, and calculate the average value based on the particle sizes of all silicon-carbon composite materials to obtain the average particle size of the silicon-carbon composite material.
  • the test equipment is a fully automatic true density tester (AccuPycII1340), and the test gas is helium.
  • Pore volume of porous carbon framework, pore volume percentage test of micropores and mesopores
  • Pore volume test of porous carbon framework The pore volume of porous carbon framework was measured by nitrogen adsorption-desorption method. At a constant temperature and low temperature -196°C (77K), the adsorption amount of nitrogen on the surface of the porous carbon skeleton was measured at different relative pressures, and the nitrogen adsorption amount when the relative pressure P 0 /P was close to 1 (P 0 /P>0.99) was regarded as
  • P 0 refers to normal pressure
  • P refers to the pressure of the gas when the nitrogen gas is desorbed.
  • the silicon-carbon composite material is heated and burned in a high-frequency furnace under oxygen-enriched conditions to oxidize carbon into carbon dioxide. After treatment, it enters the corresponding absorption pool to absorb the corresponding infrared radiation and convert it into a corresponding signal by the detector. This signal is sampled by the computer, and converted into a value proportional to the carbon dioxide concentration after linear correction, and then the value of the entire analysis process is accumulated. After the analysis, the accumulated value is divided by the weight value in the computer, and then multiplied by the correction coefficient , subtracting the blank, the mass percentage of carbon in the sample can be obtained.
  • Use high-frequency infrared carbon and sulfur analyzer (Shanghai Dekai HCS-140) to test.
  • ICP inductively coupled plasma
  • ma is the mass of the negative electrode material layer, unit: g;
  • Va is the volume of the negative electrode material layer, unit: cm 3 , where the volume Va is the product of the area Sa of the negative electrode material layer and the thickness of the negative electrode material layer.
  • test temperature is changed to 45°C, and the number of cycles at which the capacity retention rate decays to 80% is recorded as the number of cycles of the lithium-ion battery at 45°C, the rest of the test steps are the same as at 25°C.
  • first-cycle coulombic efficiency first-cycle charge capacity/first-cycle discharge capacity ⁇ 100%.
  • the positive electrode active material lithium cobaltate (LiCoO 2 ), the positive electrode conductive agent acetylene black, and the positive electrode binder polyvinylidene fluoride were mixed according to the mass ratio of 95:2.5:2.5, N-methylpyrrolidone (NMP) was added, and the Stir evenly under the action of a vacuum mixer to obtain positive electrode slurry, wherein the solid content of the positive electrode slurry is 70 wt%.
  • the positive electrode slurry was uniformly coated on one surface of a positive electrode current collector aluminum foil with a thickness of 12 ⁇ m, and dried to obtain a positive electrode sheet coated with a positive electrode material layer with a thickness of 110 ⁇ m on one side. Repeat the above steps on the other surface of the aluminum foil to obtain a positive electrode sheet coated with a positive electrode material layer on both sides. Then, after cold pressing and cutting, a positive electrode sheet with a specification of 74mm ⁇ 851mm was obtained.
  • porous carbon skeleton placed in a silane atmosphere for the first deposition reaction, wherein the porous carbon skeleton has a pore volume of 1ml/g, an average particle size of 3 ⁇ m, and a pore volume percentage of micropores and mesoporous pores of 80%;
  • the volume percentage of silane in the silane atmosphere is 20%, the rest is nitrogen, the temperature of the first deposition reaction is 500°C, and the time is 6h;
  • the average particle size of the silicon-carbon composite material is 3 ⁇ m.
  • Graphite, the silicon-carbon composite material prepared above, the negative electrode conductive agent conductive carbon black, the negative electrode binder polyacrylic acid, and the thickener sodium carboxymethyl cellulose are mixed according to the mass ratio of 86.5:10:2:0.8:0.7 , adding deionized water, stirring evenly under the action of a vacuum mixer to obtain negative electrode slurry, wherein the solid content of the negative electrode slurry is 75wt%.
  • the negative electrode slurry was uniformly coated on one surface of the negative electrode current collector copper foil, and dried to obtain a negative electrode sheet coated with a negative electrode material layer with a thickness of 130 ⁇ m on one side. Repeat the above steps on the other surface of the copper foil to obtain a negative electrode sheet coated with a negative electrode material layer on both sides. Then, after cold pressing and cutting, a negative electrode sheet with a size of 76mm ⁇ 867mm was obtained.
  • a polyethylene film (provided by Celgard) with a thickness of 7 ⁇ m was used.
  • the positive electrode sheet, separator, and negative electrode sheet prepared above in order so that the separator is placed between the positive electrode sheet and the negative electrode sheet to play the role of isolation, and the electrode assembly is obtained by winding.
  • Put the electrode assembly in an aluminum-plastic film packaging bag inject electrolyte after drying, and obtain a lithium-ion battery through processes such as vacuum packaging, standing, chemical formation, degassing, and edge trimming.
  • Embodiment 4-1 and Embodiment 4-2 are identical to Embodiment 4-1 and Embodiment 4-2.
  • Example 1-1 to Example 1-6, Comparative Example 1-1 and Comparative Example 1-2 From Example 1-1 to Example 1-6, Comparative Example 1-1 and Comparative Example 1-2, it can be seen that when the ratio of the average particle diameter of the silicon-carbon composite material to the porosity of the negative electrode material layer, and the silicon-carbon The average particle size of the composite material is within the scope of the present application, and the obtained electrochemical device has better cycle performance, expansion performance and rate performance.
  • the porosity of the negative electrode material layer usually affects the performance of the electrochemical device. When the porosity of the negative electrode material layer is within the scope of this application, the obtained electrochemical device has better cycle performance, expansion performance and rate performance.
  • the compaction density of the negative electrode material layer will also affect the porosity of the negative electrode material layer, thereby affecting the performance of the electrochemical device. From Example 1-3, Example 2-1 to Example 2-6, it can be seen that when the compacted density of the negative electrode material layer is within the scope of the application, the porosity of the negative electrode material layer obtained is also within the scope of the application. Within the range, the electrochemical device has good cycle performance, expansion performance and rate performance at the same time.
  • the content of carbon and silicon in the silicon-carbon composite directly affects the performance of the electrochemical device. It can be seen from Examples 2-3, 3-1 to 3-7 that when carbon, oxygen and If the mass percentage of silicon is within the range of the present application, the obtained electrochemical device has good cycle performance, expansion performance and rate performance, and high first-cycle reversible capacity.
  • the content of the organic solvent component in the electrolyte and the relationship between the solvent and the negative electrode active material usually affect the performance of the electrochemical device, as can be seen from Example 3-3, Example 4-1 and Example 4-2,
  • the obtained electrochemical device has good cycle performance, expansion performance and rate performance at the same time.
  • Example 4-3 to Example 4-7 it can be seen that when the electrolyte contains both EC and PC, and the mass percentages of EC and PC are within the scope of the present application, the obtained electrochemical device has good Excellent cycle performance, expansion performance and rate performance.
  • Example 3-3, Example 4-1 to Example 4-7 it can be seen that when the value of a/f is within the scope of the present application, the obtained electrochemical device has good cycle performance, expansion performance and rate performance.
  • the porous carbon skeleton used in the preparation of silicon-carbon composite materials directly affects the performance of silicon-carbon composite materials, and then affects the performance of electrochemical devices. From Example 4-5, Example 5-1 to Example 5-5, it can be seen that when the pore volume of the porous carbon skeleton, the pore volume percentage of micropores and mesopores are within the scope of the application, the obtained electrochemical The device has better cycle performance, expansion performance and rate performance.

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Abstract

本申请提供了一种电化学装置和电子装置，电化学装置包括负极极片，负极极片包括负极材料层，负极材料层包括硅碳复合材料，硅碳复合材料包括多孔碳骨架和硅材料，硅碳复合材料的Dv50为aμm，满足3≤a≤15，负极材料层的孔隙率为b％，电化学装置满足0.15≤a/b≤1。本申请提供的电化学装置具有良好的循环性能、膨胀性能和倍率性能。

Description

一种电化学装置和电子装置
本申请要求于2021年12月31日提交中国专利局、申请号为202111658562.1、发明名称为“一种电化学装置和电子装置”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及电化学技术领域，特别是涉及一种电化学装置和电子装置。
背景技术
锂离子电池具有储能密度大、开路电压高、自放电率低、循环寿命长、安全性好等优点，广泛应用于便携式电能储存、电子设备、电动汽车等各个领域。在锂离子电池飞速发展的过程中也对锂离子电池的综合性能提出更高的要求，例如同时具有较高的能量密度和良好的循环性能等。
硅材料具有高的克容量(可达4200mAh/g)，用作锂离子电池的负极活性材料能够显著提升锂离子电池的能量密度。但是，在锂离子脱嵌过程中，硅材料会产生较大的体积膨胀，具体地，其体积可增加至原先体积的300％至400％，因此容易出现硅材料破裂或粉化的问题，进而导致负极极片中的负极材料层出现粉化问题，并影响固体电解质界面(SEI)膜的形成，降低锂离子电池的循环性能。
发明内容
本申请的目的在于提供一种电化学装置和电子装置，以改善电化学装置的循环性能。
本申请的第一方面提供了一种电化学装置，其包括负极极片，所述负极极片包括负极材料层，所述负极材料层包括硅碳复合材料，所述硅碳复合材料包括多孔碳骨架和硅材料，所述硅碳复合材料的平均粒径为aμm，满足3≤a≤15，所述负极材料层的孔隙率为b％，所述电化学装置满足0.15≤a/b≤1。多孔碳骨架具有多孔结构，可以为硅碳复合材料中的硅材料提供膨胀空间以缓冲膨胀过程中产生的膨胀应力，同时通过调控硅碳复合材料的平均粒径和硅碳复合材料的平均粒径与负极材料层的孔隙率的比值在上述范围内，不仅能够为硅碳复合材料中的硅材料的体积膨胀提供足够的空间，而且使得硅碳复合材料的颗粒与颗粒之间具有良好的电接触，从而提高电化学装置的循环性能和膨胀性能，以及使电化学装置具有良好的倍率性能。
在本申请的一些实施方案中，所述负极材料层的孔隙率b％满足15≤b≤35。通过调控 负极材料层的孔隙率在上述范围内，有利于提高电化学装置的循环性能和膨胀性能，以及使电化学装置具有良好的倍率性能。
在本申请的一些实施方案中，所述负极材料层的压实密度为1.2g/cm 3至1.8g/cm 3。通过调控负极材料层的压实密度在上述范围内，有利于提高电化学装置的循环性能和膨胀性能，以及使电化学装置具有良好的倍率性能。
在本申请的一些实施方案中，基于所述硅碳复合材料的质量，所述硅碳复合材料中碳的质量百分含量为d％，满足15≤d≤75，所述硅碳复合材料中硅的质量百分含量为e％，满足15≤e≤75，所述硅碳复合材料中氧的质量百分含量为0.3％至10％。通过调控硅碳复合材料中碳、硅和氧的质量百分含量在上述范围内，有利于提高电化学装置的循环性能和膨胀性能，以及使电化学装置具有良好的倍率性能，较高的比容量、首圈可逆容量和首圈库伦效率。
在本申请的一些实施方案中，所述多孔碳骨架的孔体积为0.5ml/g至2.0ml/g，基于所述多孔碳骨架的孔体积，微孔和介孔的孔体积百分比为70％至90％。多孔碳骨架具有大量的微孔和介孔，硅碳复合材料中硅材料分布在微孔和介孔的孔结构内，为硅碳复合材料中的硅材料提供膨胀空间，能够缓冲膨胀过程中产生的膨胀应力，从而改善电化学装置的循环性能和膨胀性能。
在本申请的一些实施方案中，所述电化学装置包括电解液，所述电解液包括碳酸乙烯酯，基于所述电解液的总质量，所述碳酸乙烯酯的质量百分含量为f％，满足5≤f≤30。通过调控碳酸乙烯酯的质量百分含量在上述范围内，有利于提高电化学装置的循环性能和倍率性能。
在本申请的一些实施方案中，所述电化学装置满足0.2≤a/f≤2。通过调控a/f的值在上述范围内，有利于硅碳复合材料与电解液中的碳酸乙烯酯形成协同作用，以改善电化学装置的循环性能、膨胀性能和倍率性能。
在本申请的一些实施方案中，所述电解液包括碳酸丙烯酯，基于所述电解液的总质量，所述碳酸丙烯酯的质量百分含量为g％，满足5≤g≤40。通过调控碳酸丙烯酯的质量百分含量在上述范围内，有利于提高电化学装置的循环性能和倍率性能。
在本申请的一些实施方案中，所述硅碳复合材料的制备方法包括以下步骤：(1)将多孔碳骨架置于硅烷气氛中进行第一沉积反应，其中，所述多孔碳骨架的孔体积为0.5ml/g至2.0ml/g，基于所述多孔碳骨架的孔体积，微孔和介孔的孔体积百分比为70％至90％； 所述硅烷气氛中硅烷的体积百分比为1％至30％，所述第一沉积反应的温度为400℃至600℃、时间为1h至12h；(2)然后在氧气气氛中进行第二沉积反应得到硅碳复合材料，其中，所述氧气气氛中氧气的体积百分比为1％至30％，所述第二沉积反应的温度为400℃至800℃、时间为1h至12h。本申请提供的制备方法制得的硅碳复合材料，硅材料嵌入到多孔碳骨架的微孔和介孔中，不仅能够发挥硅材料高比容量的优势，以提高电化学装置的比容量，而且多孔碳骨架为硅材料的体积膨胀提供了足够的空间以缓解体积膨胀产生的膨胀应力，有利于改善电化学装置的循环性能和膨胀性能。
本申请的第二方面提供了一种电子装置，其包括前述任一实施方案中的电化学装置。本申请提供的电化学装置具有良好的循环性能、膨胀性能和倍率性能，从而本申请提供的电子装置具有较长的使用寿命。
本申请提供一种电化学装置和电子装置，电化学装置包括负极极片，负极极片包括负极材料层，负极材料层包括硅碳复合材料，硅碳复合材料包括多孔碳骨架和硅材料，硅碳复合材料的平均粒径为aμm，满足3≤a≤15，负极材料层的孔隙率为b％，电化学装置满足0.15≤a/b≤1。多孔碳骨架具有多孔结构，可以为硅碳复合材料中的硅材料提供膨胀空间以缓冲膨胀过程中产生的膨胀应力，同时通过调控硅碳复合材料的平均粒径和硅碳复合材料的平均粒径与负极材料层的孔隙率的比值在上述范围内，不仅能够为硅碳复合材料中的硅材料的体积膨胀提供足够的空间，而且使得硅碳复合材料的颗粒与颗粒之间具有良好的电接触，从而提高电化学装置的循环性能和膨胀性能，以及使电化学装置具有良好的倍率性能。
当然，实施本申请的任一实施方案并不一定需要同时达到以上所述的所有优点。
具体实施方式
为使本申请的目的、技术方案、及优点更加清楚明白，对本申请进一步详细说明。显然，所描述的实施例仅仅是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
需要说明的是，本申请的具体实施方案中，以锂离子电池作为电化学装置的例子来解释本申请，但是本申请的电化学装置并不仅限于锂离子电池。
本申请的第一方面提供了一种电化学装置，其包括负极极片，负极极片包括负极材料层，负极材料层包括硅碳复合材料，硅碳复合材料包括多孔碳骨架和硅材料，硅碳复合材 料的平均粒径为aμm，满足3≤a≤15，优选6≤a≤12，负极材料层的孔隙率为b％，电化学装置满足0.15≤a/b≤1，优选0.3≤a/b≤1。例如，硅碳复合材料的平均粒径可以为3μm、4μm、5μm、6μm、7μm、8μm、9μm、10μm、11μm、12μm、13μm、14μm、15μm或为其间的任意范围，a/b的值可以为0.15、0.2、0.3、0.4、0.5、0.6、0.7、0.8、0.9、1或为其间的任意范围。
本申请的发明人发现，当硅碳复合材料的平均粒径过小(例如小于3μm)时，硅碳复合材料的比表面积增加，容易与电解液发生副反应，从而影响电化学装置的循环性能。当硅碳复合材料的平均粒径过大(例如大于15μm)时，难以为硅碳复合材料中的硅材料的体积膨胀提供足够的空间，无法有效缓冲膨胀过程中产生的膨胀应力，从而影响电化学装置的循环性能和倍率性能。当a/b的值过小(例如小于0.15)或过大(例如大于1)时，均不利于改善电化学装置的循环性能、膨胀性能和倍率性能。多孔碳骨架具有多孔结构，可以为硅碳复合材料中的硅材料提供膨胀空间以缓冲膨胀过程中产生的膨胀应力，同时通过调控硅碳复合材料的平均粒径和a/b的值在上述范围内，不仅为硅碳复合材料中的硅材料的体积膨胀提供足够的空间，充分发挥硅碳复合材料中硅材料具有的高克容量优势，而且使得硅碳复合材料的颗粒与颗粒之间具有良好的电接触，从而提高电化学装置的循环性能和膨胀性能(例如体积膨胀率)，以及使电化学装置具有良好的倍率性能。
在本申请的一些实施方案中，所述负极材料层的孔隙率为b％，满足15≤b≤35，优选18≤b≤30，例如，负极材料层的孔隙率可以为15％、20％、25％、30％、35％或为其间的任意范围。当负极材料层的孔隙率过小(例如小于15％)时，不能为硅碳复合材料中的硅材料的体积膨胀提供足够的空间，会影响电化学装置的循环性能和膨胀性能。当负极材料层的孔隙率过大(例如大于35％)时，硅碳复合材料的颗粒与颗粒之间的电接触减少，会影响电化学装置的倍率性能。通过调控负极材料层的孔隙率在上述范围内，不仅能够为硅碳复合材料中的硅材料的体积膨胀提供足够的空间，还使得硅碳复合材料的颗粒与颗粒之间具有良好的电接触，从而提高电化学装置的循环性能和膨胀性能，以及使电化学装置具有良好的倍率性能。负极材料层的孔隙率是指负极材料层中的孔隙的体积与负极材料层的体积的百分比。
在本申请的一些实施方案中，负极材料层的压实密度为1.2g/cm 3至1.8g/cm 3，优选1.4g/cm 3至1.8g/cm 3。例如，负极材料层的压实密度可以为1.2g/cm 3、1.3g/cm 3、1.4g/cm 3、1.5g/cm 3、1.6g/cm 3、1.7g/cm 3、1.8g/cm 3或为其间的任意范围。当负极材料层的压实密度 过小(例如小于1.2g/cm 3)时，负极材料层的孔隙率增大，硅碳复合材料的颗粒与颗粒之间的电接触减少，会影响电化学装置的倍率性能。当负极材料层的压实密度过大(例如大于1.8g/cm 3)时，负极材料层的孔隙率降低，则不能为硅材料的体积膨胀提供足够的空间以释放膨胀过程中产生的膨胀应力，会影响电化学装置的循环性能和膨胀性能。通过调控负极材料层的压实密度在上述范围内，有利于提高电化学装置的循环性能和膨胀性能，以及使电化学装置具有良好的倍率性能。
在本申请的一些实施方案中，基于硅碳复合材料的质量，硅碳复合材料中碳的质量百分含量为d％，满足15≤d≤75，优选为40≤d≤75，硅碳复合材料中硅的质量百分含量为e％，满足15≤e≤75，优选为40≤e≤75，硅碳复合材料中氧的质量百分含量为0.3％至10％，优选为1％至6％。例如，硅碳复合材料中碳的质量百分含量可以为15％、20％、30％、40％、50％、60％、70％、75％或为其间的任意范围，硅碳复合材料中硅的质量百分含量可以为15％、20％、30％、40％、50％、60％、70％、75％或为其间的任意范围，硅碳复合材料中氧的质量百分含量可以为0.3％、0.5％、1％、2％、3％、4％、5％、6％、7％、8％、9％、10％或为其间的任意范围。可以理解的是，硅碳复合材料中可能会存在少量(质量百分含量小于0.1％)的杂质，为了方便讨论，本申请对杂质忽略不计，即硅碳复合材料中硅、碳和氧的质量百分含量之和为100％。
本申请的发明人发现，当硅碳复合材料中碳的质量百分含量过低(例如低于15％)时，不能为硅碳复合材料中硅材料提供足够的膨胀空间，从而会影响电化学装置的循环性能和膨胀性能。当硅碳复合材料中碳的质量百分含量过高(例如高于75％)时，此时硅的质量百分含量较低，无法有效发挥硅碳复合材料中硅材料具有的高克容量优势，会影响电池的比容量。通过调控硅碳复合材料中碳的质量百分含量在上述范围内，有利于提高电化学装置的循环性能和膨胀性能，以及使电化学装置具有较高的比容量。
当硅碳复合材料中硅的质量百分含量过低(例如低于15％)时，会影响电化学装置的首圈可逆容量，也无法有效发挥硅碳复合材料中硅材料具有的高克容量优势，会影响电池的比容量。当硅碳复合材料中硅的质量百分含量过高(例如高于75％)时，此时碳的质量百分含量较低，则不能为硅碳复合材料中的硅材料提供足够的膨胀空间，从而会影响电化学装置的循环性能和膨胀性能；此外，硅的质量百分含量过高不利于锂离子和电子的传输，从而影响电化学装置的倍率性能。通过调控硅碳复合材料中硅的质量百分含量在上述范围内，有利于提高电化学装置的循环性能和膨胀性能，以及使电化学装置具有良好的倍率性 能、较高的首圈可逆容量和比容量。
硅碳复合材料中的氧会与锂离子在硅碳复合材料的表面形成惰性层，能够改善硅碳复合材料中硅材料的膨胀性能，进而可以改善电化学装置的循环性能和膨胀性能。但是，当硅碳复合材料中氧的质量百分含量过高(例如高于10％)时，形成的惰性层会影响锂离子的传输，进而影响电化学装置的倍率性能和首圈库伦效率。通过调控硅碳复合材料中氧的质量百分含量在上述范围内，有利于提高电化学装置的循环性能和膨胀性能，以及使电化学装置具有良好的倍率性能和较高的首圈库伦效率。
整体而言，通过调控硅碳复合材料中碳、硅和氧的质量百分含量在上述范围内，有利于提高电化学装置的循环性能和膨胀性能，以及使电化学装置具有良好的倍率性能，较高的比容量、首圈可逆容量和首圈库伦效率。
在本申请的一些实施方案中，硅碳复合材料满足0.5≤d/e≤5，优选0.8≤d/e≤3例如，d/e的值可以为0.5、1、2、3、4、5或为其间的任意范围。通过调控d/e的值在上述范围内，有利于提高电化学装置的循环性能和膨胀性能，以及使电化学装置具有良好的倍率性能。
在本申请的一些实施方案中，多孔碳骨架的孔体积为0.5ml/g至2.0ml/g，优选为0.8ml/g至2.0ml/g，基于多孔碳骨架的孔体积，微孔和介孔的孔体积百分比为70％至90％，优选为80％至90％。例如，多孔碳骨架的孔体积可以为0.5ml/g、0.6ml/g、0.7ml/g、0.8ml/g、0.9ml/g、1.0ml/g、1.1ml/g、1.2ml/g、1.3ml/g、1.5ml/g、1.8ml/g、2.0ml/g或为其间的任意范围，微孔和介孔的孔体积百分比为70％、75％、80％、85％、90％或为其间的任意范围。多孔碳骨架具有大量的微孔和介孔，硅碳复合材料中硅材料分布在微孔和介孔的孔结构内，为硅碳复合材料中的硅材料提供膨胀空间，能够缓冲膨胀过程中产生的膨胀应力，从而改善电化学装置的循环性能和膨胀性能。其中，微孔和介孔的孔体积百分比是指微孔和介孔的孔体积之和与多孔碳骨架的孔体积之比的百分数，微孔是指孔径小于2nm的孔，介孔是指孔径在2nm至50nm之间的孔。
在本申请的一些实施方案中，电化学装置包括电解液，电解液包括碳酸乙烯酯(EC)，基于电解液的总质量，碳酸乙烯酯的质量百分含量为f％，满足5≤f≤30，优选为10≤f≤30。例如，EC的质量百分含量可以为5％、10％、15％、20％、25％、30％或为其间的任意范围。在电解液中加入EC，由于EC具有较高的介电常数，有利于提高电化学装置的倍率性能，同时当EC渗透到硅碳复合材料的表面后，有利于在负极极片的表面形成稳定的SEI膜，从而有利于提高电化学装置的循环性能。但是当EC的质量百分含量过高(例如高于 30％)，电解液粘度增大，不利于锂离子的传输，电解液的电导率降低，而且EC会与锂离子一起嵌入到硅碳复合材料中，使得可逆容量降低，从而影响电化学装置的倍率性能、循环性能和容量。通过调控EC的质量百分含量在上述范围内，有利于提高电化学装置的循环性能和倍率性能。
在本申请的一些实施方案中，电化学装置满足0.2≤a/f≤2，优选为0.2≤a/f≤1.5。例如，a/f的值可以为0.2、0.4、0.6、0.8、1、1.2、1.5、2或为其间的任意范围。当a/f的值过小(例如小于0.2)时，也即硅碳复合材料的平均粒径较小或EC的质量百分含量较高，均会影响电化学装置的倍率性能。当a/f的值过大(例如大于2)时，也即硅碳复合材料的平均粒径较大或EC的质量百分含量较低，会影响电化学装置的循环性能、膨胀性能和倍率性能。通过调控a/f的值在上述范围内，有利于硅碳复合材料与电解液中的EC形成协同作用，以改善电化学装置的循环性能、膨胀性能和倍率性能。
在本申请的一些实施方案中，电解液包括碳酸丙烯酯(PC)，基于电解液的总质量，碳酸丙烯酯的质量百分含量为g％，满足5≤g≤40，优选为10≤g≤30。例如，PC的质量百分含量可以为5％、10％、20％、30％、40％或为其间的任意范围。在电解液中加入PC，由于PC具有较高的介电常数，有利于提高电化学装置的倍率性能，同时当PC渗透到硅碳复合材料的表面后，有利于在负极极片的表面形成稳定的SEI膜，从而有利于提高电化学装置的循环性能。但是当PC的质量百分含量过高(例如高于40％)，电解液粘度增大，不利于锂离子的传输，电解液的电导率降低，而且PC存在析出的风险，从而影响电化学装置的循环性能、膨胀性能和倍率性能。通过调控PC的质量百分含量在上述范围内，有利于提高电化学装置的循环性能和倍率性能。
在本申请的一些实施方案中，硅碳复合材料的制备方法包括以下步骤：(1)将多孔碳骨架置于硅烷气氛中进行第一沉积反应，其中，多孔碳骨架的孔体积为0.5ml/g至2.0ml/g，基于多孔碳骨架的孔体积，微孔和介孔的孔体积百分比为70％至90％；硅烷气氛中硅烷的体积百分比为1％至30％，第一沉积反应的温度为400℃至600℃、时间为1h至12h；(2)然后在氧气气氛中进行第二沉积反应得到硅碳复合材料，其中，氧气气氛中氧气的体积百分比为1％至30％，第二沉积反应的温度为400℃至800℃、时间为1h至12h。上述制备方法制得的硅碳复合材料，硅材料嵌入到多孔碳骨架的微孔和介孔中，不仅能够发挥硅材料高克容量的优势，以提高电化学装置的比容量，而且多孔碳骨架为硅材料的体积膨胀提供了足够的空间以缓解体积膨胀产生的膨胀应力，有利于改善电化学装置的循环性能和膨胀 性能。其中，上述硅氧烷气氛和氧气气氛中还包括惰性气体，惰性气体可以包括但不限于氮气、氩气或氦气中的至少一种。
在制备硅碳复合材料时，可以通过调整多孔碳骨架的平均粒径来调整硅碳复合材料的平均粒径。通常情况下，增大多孔碳骨架的平均粒径，硅碳复合材料的平均粒径增大；减小多孔碳骨架的平均粒径，硅碳复合材料的平均粒径减小。本申请对多孔碳骨架的平均粒径没有特别限制，只要能满足前述硅碳复合材料的平均粒径即可，例如，多孔碳骨架的平均粒径为1μm至20μm。
第一沉积反应和第二沉积反应的温度和时间通常会影响硅碳复合材料的性能。例如，升高第一沉积反应温度，可提高硅材料的晶化程度，有利于改善电化学装置的首圈库伦效率，但会影响其膨胀性能；升高第二沉积反应的温度，可提高硅材料表面的钝化层厚度，进而提高硅碳复合材料的加工稳定性；延长第一沉积反应的时间，有利于提高硅碳复合材料的硅含量，有利于改善电化学装置的比容量，而过高的硅含量会影响电化学装置的膨胀性能；延长第二沉积反应的时间，可提高硅材料表面的钝化层厚度，提高硅碳复合材料的加工稳定性；降低第一沉积反应温度，会降低硅材料的晶化程度，影响电化学装置首圈库伦效率的发挥；降低第二沉积反应的温度，不利于硅材料表面形成稳定的钝化层；缩短第一沉积反应的时间，硅含量相应降低，适量的硅含量有利于改善电化学装置的循环性能和膨胀性能；缩短第二沉积反应的时间，会影响硅材料表面形成稳定的钝化层的厚度。通过调控第一沉积反应的温度和时间、第二沉积反应的温度和时间在上述范围内，有利于提高硅碳复合材料的表面稳定性，有利于改善电化学装置的首圈库伦效率、循环性能和膨胀性能。示例性地，多孔碳骨架可以包括但不限于天然石墨、人造石墨、中间相微碳球、硬碳或软碳中的至少一种，硅材料可以包括但不限于晶体硅或无定形硅中的至少一种。
本申请中，负极极片还包括负极集流体，本申请对负极集流体没有特别限制，只要能够实现本申请目的即可，例如，可以包括但不限于铜箔、铜合金箔、镍箔、不锈钢箔、钛箔、泡沫镍、泡沫铜或复合集流体等。负极材料层可以设置在沿负极集流体厚度方向的一个表面或两个表面上。需要说明，这里的“表面”可以是负极集流体的全部区域，也可以是负极集流体的部分区域，本申请没有特别限制，只要能实现本申请目的即可。在本申请中，对负极的集流体的厚度没有特别限制，只要能够实现本申请目的即可，例如厚度为4μm至12μm。
在本申请中，负极材料层除了包括上述硅碳复合材料以外，还可以包括本领域已知的 其它负极活性材料，例如，可以包括但不限于天然石墨、人造石墨、中间相微碳球、硬碳、软碳、硅、硅-碳复合物、Li-Sn合金、Li-Sn-O合金、Sn、SnO、SnO 2、尖晶石结构的锂化TiO 2-Li 4Ti 5O 12或Li-Al合金中的至少一种。
在本申请中，负极材料层中还可以包括负极导电剂，本申请对负极导电剂没有特别限制，只要能够实现本申请目的即可，例如可以包括但不限于基于碳的材料、基于金属的材料或导电聚合物中的至少一种。上述基于碳的材料选自天然石墨、人造石墨、导电碳黑、乙炔黑、科琴黑或碳纤维中的至少一种。上述基于金属的材料可以包括但不限于金属粉和/或金属纤维，具体地，金属可以包括但不限于铜、镍、铝或银中的至少一种。导电聚合物可以包括但不限于聚亚苯基衍生物、聚苯胺、聚噻吩、聚乙炔或聚吡咯中的至少一种。
在本申请中，负极材料层中还可以包括负极粘结剂，本申请对负极粘结剂没有特别限制，只要能够实现本申请目的即可，例如可以包括但不限于聚乙烯醇、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、聚丙烯酸、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。
任选地，负极极片还可以包括导电层，导电层位于负极集流体和负极材料层之间。本申请对导电层的组成没有特别限制，可以是本领域常用的导电层，导电层可以包括但不限于上述负极导电剂和上述负极粘结剂。
本申请的电解液还包括锂盐和其它非水溶剂，本申请对锂盐没有特别限制，只要能实现本申请的目的即可，例如可以包括但不限于LiPF 6、LiBF 4、LiAsF 6、LiClO 4、LiB(C 6H 5) 4、LiCH 3SO 3、LiCF 3SO 3、LiN(SO 2CF 3) 2、LiC(SO 2CF 3) 3、LiSiF 6、LiBOB或者二氟硼酸锂中的至少一种。优选地，锂盐包括LiPF 6。
本申请对其它非水溶剂没有特别限制，只要能实现本申请的目的即可，例如可以包括但不限于碳酸酯化合物、羧酸酯化合物、醚化合物或其它有机溶剂中的至少一种。上述碳酸酯化合物可以包括但不限于链状碳酸酯化合物、环状碳酸酯化合物或氟代碳酸酯化合物中的至少一种。上述链状碳酸酯化合物可以包括但不限于碳酸二甲酯(DMC)、碳酸二乙酯(DEC)、碳酸二丙酯(DPC)、碳酸甲丙酯(MPC)、碳酸乙丙酯(EPC)或碳酸甲乙酯(MEC)中的至少一种。上述环状碳酸酯可以包括但不限于碳酸亚丁酯(BC)或碳酸乙烯基亚乙酯(VEC)中的至少一种。氟代碳酸酯化合物可以包括但不限于氟代碳酸乙烯酯(FEC)、碳酸1,2-二氟亚乙酯、碳酸1,1-二氟亚乙酯、碳酸1,1,2-三氟亚乙酯、碳酸1,1,2,2- 四氟亚乙酯、碳酸1-氟-2-甲基亚乙酯、碳酸1-氟-1-甲基亚乙酯、碳酸1,2-二氟-1-甲基亚乙酯、碳酸1,1,2-三氟-2-甲基亚乙酯或碳酸三氟甲基亚乙酯中的至少一种。上述羧酸酯化合物可以包括但不限于甲酸甲酯、乙酸甲酯、乙酸乙酯、乙酸正丙酯、乙酸叔丁酯、丙酸甲酯、丙酸乙酯、丙酸丙酯、γ-丁内酯、癸内酯、戊内酯或己内酯中的至少一种。上述醚化合物可以包括但不限于二丁醚、四甘醇二甲醚、二甘醇二甲醚、1,2-二甲氧基乙烷、1,2-二乙氧基乙烷、1-乙氧基-1-甲氧基乙烷、2-甲基四氢呋喃或四氢呋喃中的至少一种。上述其它有机溶剂可以包括但不限于二甲亚砜、1,2-二氧戊环、环丁砜、甲基环丁砜、1,3-二甲基-2-咪唑烷酮、N-甲基-2-吡咯烷酮、二甲基甲酰胺、乙腈、磷酸三甲酯、磷酸三乙酯或磷酸三辛酯中的至少一种。基于电解液的总质量，上述其它非水溶剂的质量百分含量为17％至83％，例如可以17％、17.5％、20％、30％、40％、50％、60％、70％、80％、82.5％、83％或为其间的任意范围。
本申请的电化学装置还可以包括正极极片，本申请对正极极片没有特别限制，只要能实现本申请的目的即可，例如正极极片通常包括正极集流体和正极材料层。正极材料层可以设置于正极集流体厚度方向上的一个表面上，也可以设置于正极集流体厚度方向上的两个表面上。需要说明，这里的“表面”可以是正极集流体的全部区域，也可以是正极集流体的部分区域，本申请没有特别限制，只要能实现本申请目的即可。在本申请中，正极集流体没有特别限制，只要能够实现本申请目的即可，例如可以包括但不限于铝箔、铝合金箔或复合集流体等。在本申请中，对正极集流体的厚度没有特别限制，只要能够实现本申请目的即可，例如厚度为8μm至12μm。
在本申请中，正极材料层中包括正极活性材料，本申请对正极活性材料没有特别限制，只要能够实现本申请目的即可，例如可以包括锂或过渡金属元素的复合氧化物中的至少一种。本申请对上述过渡金属元素没有特别限制，只要能实现本申请的目的即可，例如可以包括镍、锰、钴或铁中的至少一种。具体的，正极活性材料可以包括镍钴锰酸锂、镍钴铝酸锂、磷酸铁锂、富锂锰基材料、钴酸锂、锰酸锂、磷酸锰铁锂或钛酸锂中的至少一种。
在本申请中，正极材料层中还可以包括正极导电剂，本申请对正极导电剂没有特别限制，只要能够实现本申请目的即可，例如可以包括但不限于导电炭黑(Super P)、碳纳米管(CNTs)、碳纤维、乙炔黑、鳞片石墨、科琴黑、石墨烯、金属材料或导电聚合物中的至少一种，优选地，正极导电剂包括导电炭黑和碳纳米管。上述碳纳米管可以包括但不限于单壁碳纳米管和/或多壁碳纳米管。上述碳纤维可以包括但不限于气相生长碳纤维(VGCF) 和/或纳米碳纤维。上述金属材料可以包括但不限于金属粉和/或金属纤维，具体地，金属可以包括但不限于铜、镍、铝或银中的至少一种。上述导电聚合物可以包括但不限于聚亚苯基衍生物、聚苯胺、聚噻吩、聚乙炔或聚吡咯中的至少一种。在本申请中，正极材料层还可以包括正极粘结剂，本申请对正极粘结剂没有特别限制，只要能够实现本申请目的即可，例如可以包括但不限于含氟树脂、聚丙烯树脂、纤维型粘结剂、橡胶型粘结剂或聚酰亚胺型粘结剂中的至少一种。
任选地，正极极片还可以包括导电层，导电层位于正极集流体和正极材料层之间。本申请对导电层的组成没有特别限制，可以是本领域常用的导电层，例如可以包括但不限于上述正极导电剂和上述正极粘结剂。
本申请的电化学装置还可以包括隔离膜，本申请对隔离膜没有特别限制，只要能够实现本申请目的即可。上述隔离膜可以包括基材层和表面处理层，本申请对基材层的材料没有特别限制，例如可以包括但不限于聚乙烯、聚丙烯、聚四氟乙烯为主的聚烯烃、聚酯膜(例如聚对苯二甲酸二乙酯)、纤维素、聚酰亚胺、聚酰胺、氨纶、芳纶中的至少一种；基材层的类型可以包括但不限于织造膜、非织造膜、微孔膜、复合膜、隔膜纸、碾压膜或纺丝膜中的至少一种，基材层的材料优选为聚乙烯或聚丙烯，它们对防止短路具有良好的作用，并可以通过关断效应改善电化学装置的稳定性。本申请的隔离膜可以具有多孔结构，孔径的尺寸没有特别限制，只要能实现本申请的目的即可，例如，孔径的尺寸可以为0.01μm至1μm。在本申请中，隔离膜的厚度没有特别限制，只要能实现本申请的目的即可，例如厚度可以为5μm至500μm。
在本申请中，上述基材层的至少一个表面上设置有表面处理层，本申请对表面处理层没有特别限制，可以是聚合物层或无机物层，也可以是混合聚合物与无机物所形成的层。无机物层可以包括但不限于无机颗粒和无机物层粘结剂，本申请对无机颗粒没有特别限制，例如，可以包括但不限于氧化铝、氧化硅、氧化镁、氧化钛、二氧化铪、氧化锡、二氧化铈、氧化镍、氧化锌、氧化钙、氧化锆、氧化钇、碳化硅、勃姆石、氢氧化铝、氢氧化镁、氢氧化钙或硫酸钡中的至少一种。本申请对无机物层粘结剂没有特别限制，例如，可以包括但不限于聚偏氟乙烯、偏氟乙烯-六氟丙烯的共聚物、聚酰胺、聚丙烯腈、聚丙烯酸酯、聚丙烯酸、聚丙烯酸盐、聚乙烯呲咯烷酮、聚乙烯醚、聚甲基丙烯酸甲酯、聚四氟乙烯或聚六氟丙烯中的至少一种。聚合物层中包含聚合物，本申请对聚合物没有特别限制，聚合物的材料可以包括但不限于聚酰胺、聚丙烯腈、丙烯酸酯聚合物、聚丙烯酸、聚丙烯酸盐、聚乙烯呲咯烷酮、聚乙烯醚、聚偏氟乙烯或聚(偏氟乙烯-六氟丙烯)中的至少一种。
本申请的电化学装置没有特别限制，其可以包括发生电化学反应的任何装置。在一些实施方案中，电化学装置可以包括但不限于锂离子电池。
电化学装置的制备过程为本领域技术人员所熟知的，本申请没有特别的限制，例如，可以包括但不限于以下步骤：将正极极片、隔离膜和负极极片按顺序堆叠，并根据需要将其卷绕、折叠等操作得到卷绕结构的电极组件，将电极组件放入包装袋内，将电解液注入包装袋并封口，得到电化学装置；或者，将正极极片、隔离膜和负极极片按顺序堆叠，然后用胶带将整个叠片结构的四个角固定好得到叠片结构的电极组件，将电极组件置入包装袋内，将电解液注入包装袋并封口，得到电化学装置。此外，也可以根据需要将防过电流元件、导板等置于包装袋中，从而防止电化学装置内部的压力上升、过充放电。
本申请的第二方面提供了一种电子装置，其包括前述任一实施方案中的电化学装置。本申请提供的电化学装置具有良好的循环性能、膨胀性能和倍率性能，从而本申请提供的电子装置具有较长的使用寿命。
本申请的电子装置没有特别限定，其可以是用于现有技术中已知的任何电子装置。在一些实施例中，电子装置可以包括，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、家庭用大型蓄电池和锂离子电容器等。
实施例
以下，举出实施例及对比例来对本申请的实施方案进行更具体地说明。各种的试验及评价按照下述的方法进行。另外，只要无特别说明，“份”、“％”为质量基准。
测试方法和设备：
平均粒径测试：
此处特别需要指出的是：在负极极片中，由于所述硅碳复合材料和石墨、粘结剂、分散剂与导电剂材料混合使用，为便于较准确表征负极极片中所述硅碳复合材料的平均粒径，作以下定义来测试表征负极极片中所述硅碳复合材料的平均粒径：结合扫描电镜测试方法，使用扫描电镜(ZEISS Sigma-02-33)设备在背散模式下(0.1KV至30KV)，在100K的倍率下，在颜色的对比度上颜色最浅的颗粒为硅碳复合材料对应的颗粒，以上述各个颗粒中 存在的两点之间最长距离的数值作为该颗粒的粒径，统计该100K倍率下所有硅碳复合材料的粒径，并根据所有硅碳复合材料的粒径计算得出平均值，得到硅碳复合材料的平均粒径。
孔隙率测试：
采用气体置换法测试负极材料层的孔隙率，孔隙率＝(V-V0)/V×100％，孔体积为V-V0，其中，V0为被测样品的真实体积，V为被测样品的总体积。测试设备为全自动真密度测试仪(AccuPycⅡ1340)，测试气体为氦气。
多孔碳骨架的孔体积、微孔和介孔的孔体积百分比测试：
多孔碳骨架的孔体积测试：利用氮气吸脱附法测量多孔碳骨架的孔体积。在恒温低温-196℃(77K)下，测定不同相对压力时氮气在多孔碳骨架表面的吸附量，将相对压力P 0/P接近1(P 0/P＞0.99)时的氮气吸附量看作饱和吸附量Vs，取氮气饱和吸附量冷凝后的体积作为多孔碳骨架的孔体积：V 1＝Vs×0.001547。其中，P 0是指常压，P是指氮气脱附出来时气体的压力。
微孔和介孔的孔体积百分比计算：称取2g硅碳复合材料的粉末样品装入全自动比表面积及孔隙度分析仪(TriStar II 3020)的测试样品管中，200℃脱气120min后，利用氮气吸脱附法测得多孔碳骨架的氮气吸脱附等温线，采用非线性密度泛函理论(NLDFT理论)计算得到多孔碳骨架内的孔径分布，以孔径为x轴、孔体积为y轴作图得到孔径分布曲线，取孔径x＞0nm范围内孔径分布曲线下覆盖的面积Sa与分布曲线下覆盖的总面积S的比值：a＝Sa/S×100％作为多孔碳骨架内的微孔和介孔的孔体积百分比。
碳的质量百分含量的测试：
将硅碳复合材料在富氧条件下由高频炉高温加热燃烧使碳氧化成二氧化碳，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，即可获得样品中碳的质量百分含量。利用高频红外碳硫分析仪(上海徳凯HCS-140)进行测试。
硅的质量百分含量的测试：
取硅碳复合材料5g，置于聚四氟乙烯(PTFE)材质的烧杯中，缓慢加入10ml浓硝酸和2ml氢氟酸，加热到220℃，使硅碳复合材料完全溶解得到样品溶液，然后摇动样品溶 液，缓慢倒入单层滤纸的漏斗中，并冲洗烧杯与滤渣三次，水温在20℃±5℃，定容至100ml，摇匀，使用电感耦合等离子体(ICP)设备(PE 7000DV)，测试溶液中硅的质量为x，则粉末中硅的质量百分含量y＝x/5×100％。
压实密度测试：
负极材料层的压实密度Pa通过公式：Pa＝ma/Va计算得出。式中，ma为负极材料层的质量，单位：g；Va为负极材料层的体积，单位：cm 3，其中，体积Va是负极材料层的面积Sa与负极材料层的厚度之积。
循环性能测试：
将锂离子电池在测试温度为25℃下，以0.7C恒流充电到4.4V，以4.4V恒压充电到0.025C，静置5min后，以0.5C恒流放电到3.0V，此为一个循环，并测试锂离子电池的容量记为初始容量，然后进行多次循环，以每一次循环得到的容量与初始容量相比得到容量保持率和容量衰减曲线。以容量保持率衰减为90％的圈数记为锂离子电池在25℃下的循环圈数。
除了将测试温度更改为45℃，以容量保持率衰减为80％的圈数记为锂离子电池在45℃下的循环圈数，其余与25℃下测试步骤相同。
膨胀性能测试：
在测试温度为25℃下，用螺旋千分尺测试锂离子电池在50％荷电状态(SOC)下的厚度，记为H0，然后按照循环性能测试中的步骤循环至500圈时，测试锂离子电池在100％SOC下的厚度，记为H1。25℃循环膨胀率＝(H1-H0)/H0×100％。
将测试温度更改为45℃，其余与25℃下测试步骤相同，则可计算得到45℃循环膨胀率。
倍率性能测试：
在测试温度为25℃下，将锂离子电池以0.2C恒流放电到3.0V，静置5min，以0.5C恒流充电到4.45V，以4.45V恒压充电到0.05C后静置5min，调整放电倍率，分别以0.2C和2.0C进行放电测试，得到对应的放电容量，2.0C与0.2C下放电容量的比值百分数作为衡量倍率性能依据。
首圈可逆容量测试：
在测试温度为25℃下，将锂离子电池以0.2C恒流放电到3.0V，静置5min，以0.5C恒流充电到4.45V，以4.45V恒压充电到0.05C后静置5min，测试得到的充电容量即为首圈可逆容量。
首圈库伦效率测试：
在测试温度为25℃下，将锂离子电池以0.2C恒流放电到3.0V，静置5min，以0.5C恒流充电到4.45V，以4.45V恒压充电到0.05C后静置5min，测试锂离子电池的首圈充电容量和首圈放电容量，根据以下公式计算首圈库伦效率：首圈库伦效率＝首圈充电容量/首圈放电容量×100％。
实施例1-1
<正极极片的制备>
将正极活性材料钴酸锂(LiCoO 2)、正极导电剂乙炔黑、正极粘结剂聚偏二氟乙烯按照质量比为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，其中正极浆料的固含量为70wt％。将正极浆料均匀涂覆于厚度为12μm的正极集流体铝箔的一个表面上，烘干，得到单面涂覆有厚度为110μm正极材料层的正极极片。在铝箔的另一个表面上重复以上步骤，即得到双面涂覆有正极材料层的正极极片。然后经过冷压、裁切后得到规格为74mm×851mm正极极片。
<硅碳复合材料的制备>
(1)将多孔碳骨架置于硅烷气氛中进行第一沉积反应，其中，多孔碳骨架的孔体积为1ml/g、平均粒径为3μm，微孔和介孔的孔体积百分比为80％；硅烷气氛中硅烷的体积百分比为20％，其余为氮气，第一沉积反应的温度为500℃、时间为6h；
(2)然后在氧气气氛中进行第二沉积反应，对第一沉积反应中得到的物质进行钝化处理，通过氧气将第一沉积反应中暴露出来的硅进行氧化，得到硅碳复合材料，其中，氧气气氛中氧气的体积百分比为20％，其余为氮气，第二沉积反应的温度为500℃、时间为5h。
其中，硅碳复合材料的平均粒径为3μm。
<负极极片的制备>
将石墨、上述制备得到的硅碳复合材料、负极导电剂导电炭黑、负极粘结剂聚丙烯酸、增稠剂羧甲基纤维素钠按照质量比为86.5:10:2:0.8:0.7进行混合，加入去离子水，在真空搅拌机作用下搅拌均匀，获得负极浆料，其中负极浆料的固含量为75wt％。将负极浆料均匀涂覆于负极集流体铜箔的一个表面上，烘干，得到单面涂覆有厚度为130μm负极材料层的负极极片。在铜箔的另一个表面上重复以上步骤，即得到双面涂覆有负极材料层的负极极片。然后经过冷压、裁切后得到规格为76mm×867mm负极极片。
<电解液的制备>
在含水量<10ppm的氩气气氛手套箱中，将一定量的EC和DEC混合均匀得到有机溶剂，然后向有机溶剂中加入锂盐LiPF 6并混合均匀，得到电解液。其中，基于电解液的总质量，锂盐的质量百分含量为12.5％，EC的质量百分含量为25％，其余为DEC。
<隔离膜的制备>
采用厚度为7μm的聚乙烯薄膜(Celgard公司提供)。
<锂离子电池的制备>
将上述制备得到的正极极片、隔离膜、负极极片按顺序叠好，使隔离膜处于正极极片和负极极片中间以起到隔离的作用，卷绕得到电极组件。将电极组件置于铝塑膜包装袋中，干燥后注入电解液，经过真空封装、静置、化成、脱气、切边等工序得到锂离子电池。
实施例1-2至实施例1-6
除了调整多孔碳骨架的平均粒径使硅碳复合材料的平均粒径和负极材料层的孔隙率如表1所示以外，其余与实施例1-1相同。
实施例2-1至实施例2-6
除了调整多孔碳骨架的平均粒径使负极材料层的压实密度和孔隙率如表2所示以外，其余与实施例1-3相同。
实施例3-1至实施例3-7
除了调整第一沉积反应和第二沉积反应中的参数使硅碳复合材料中碳和硅的质量百分含量如表3所示以外，其余与实施例2-3相同。
实施例4-1和实施例4-2
除了按照表4所示调整EC的质量百分含量，以及硅碳复合材料的平均粒径以外，其余与实施例3-3相同。
实施例4-3和实施例4-7
除了在<电解液的制备>中制备有机溶剂时还加入PC，并按照表4所示调整EC和PC的质量百分含量，以及硅碳复合材料的平均粒径以外，其余与实施例3-3相同。
实施例5-1至实施例5-5
除了调整采用如表5所示的多孔碳骨架制备硅碳复合材料以外，其余与实施例4-5相同。
对比例1-1至对比例1-2
除了调整多孔碳的平均粒径使硅碳复合材料的平均粒径和负极材料层的孔隙率如表1所示以外，其余与实施例1-1相同。
各实施例和对比例的制备参数及性能测试如表1至表5所示。
表1
Figure PCTCN2022121787-appb-000001
从实施例1-1至实施例1-6、对比例1-1和对比例1-2可以看出，当硅碳复合材料的平均粒径和负极材料层的孔隙率的比值，以及硅碳复合材料的平均粒径同时在本申请的范围内，得到的电化学装置同时具有更好的循环性能、膨胀性能和倍率性能。此外，负极材料层的孔隙率通常会影响电化学装置的性能，当负极材料层的孔隙率在本申请的范围内，得到的电化学装置同时具有更好的循环性能、膨胀性能和倍率性能。
表2
Figure PCTCN2022121787-appb-000002
负极材料层的压实密度也会影响负极材料层的孔隙率，进而影响电化学装置的性能。从实施例1-3、实施例2-1至实施例2-6可以看出，当负极材料层的压实密度在本申请的范 围内，得到的负极材料层的孔隙率也在本申请的范围内，电化学装置同时具有良好的循环性能、膨胀性能和倍率性能。
表3
Figure PCTCN2022121787-appb-000003
硅碳复合材料中碳和硅的含量直接影响电化学装置的性能，从实施例2-3、实施例3-1至实施例3-7可以看出，当硅碳复合材料中碳、氧和硅的质量百分含量在本申请的范围内，得到的电化学装置同时具有良好的循环性能、膨胀性能和倍率性能，以及较高的首圈可逆容量。
表4
Figure PCTCN2022121787-appb-000004
注：表4中的“/”表示不存在对应的参数或物质。
电解液中有机溶剂组分的含量以及溶剂和负极活性材料之间的关系通常会影响电化学装置的性能，从实施例3-3、实施例4-1和实施例4-2可以看出，当电解液中包含EC且 EC的质量百分含量在本申请的范围内，得到的电化学装置同时具有良好的循环性能、膨胀性能和倍率性能。从实施例4-3至实施例4-7可以看出，当电解液中同时包含EC和PC，且EC和PC的质量百分含量在本申请的范围内，得到的电化学装置同时具有良好的循环性能、膨胀性能和倍率性能。从实施例3-3、实施例4-1至实施例4-7可以看出，当a/f的值在本申请的范围内，得到的电化学装置同时具有良好的循环性能、膨胀性能和倍率性能。
表5
Figure PCTCN2022121787-appb-000005
制备硅碳复合材料所采用的多孔碳骨架直接影响硅碳复合材料的性能，进而影响电化学装置的性能。从实施例4-5、实施例5-1至实施例5-5可以看出，当多孔碳骨架的孔体积、微孔和介孔的孔体积百分比在本申请的范围内，得到的电化学装置具有更好的循环性能、膨胀性能和倍率性能。
需要说明的是，在本文中，诸如第一和第二等之类的关系术语仅仅用来将一个实体或操作与另一个实体或操作区分开来，而不一定要求或者暗示这些实体或操作之间存在任何这种实际的关系或者顺序。而且，术语“包括”、“包含”或者其任何其它变体意在涵盖非排他性的包含，从而使得包括一系列要素的过程、方法、物品或者设备不仅包括那些要素，而且还包括没有明确列出的其它要素，或者是还包括为这种过程、方法、物品或者设备所固有的要素。
本说明书中的各个实施方案均采用相关的方式描述，各个实施方案之间相同相似的部分互相参见即可，每个实施方案重点说明的都是与其它实施例的不同之处。
以上所述仅为本申请的较佳实施例，并不用以限制本申请，凡在本申请的精神和原则之内，所做的任何修改、等同替换、改进等，均应包含在本申请保护的范围之内。

Claims (11)

  1. 一种电化学装置，其包括负极极片，所述负极极片包括负极材料层，所述负极材料层包括硅碳复合材料，所述硅碳复合材料包括多孔碳骨架和硅材料，所述硅碳复合材料的平均粒径为aμm，满足3≤a≤15，所述负极材料层的孔隙率为b％，所述电化学装置满足0.15≤a/b≤1。
  2. 根据权利要求1所述的电化学装置，其中，所述负极材料层的孔隙率b％满足15≤b≤35。
  3. 根据权利要求1所述的电化学装置，其中，所述负极材料层的压实密度为1.2g/cm 3至1.8g/cm 3。
  4. 根据权利要求1所述的电化学装置，其中，基于所述硅碳复合材料的质量，所述硅碳复合材料中碳的质量百分含量为d％，满足15≤d≤75，所述硅碳复合材料中硅的质量百分含量为e％，满足15≤e≤75，所述硅碳复合材料中氧的质量百分含量为0.3％至10％。
  5. 根据权利要求1所述的电化学装置，其中，所述多孔碳骨架的孔体积为0.5ml/g至2.0ml/g，基于所述多孔碳骨架的孔体积，微孔和介孔的孔体积百分比为70％至90％。
  6. 根据权利要求1所述的电化学装置，其包括电解液，所述电解液包括碳酸乙烯酯，基于所述电解液的总质量，所述碳酸乙烯酯的质量百分含量为f％，满足5≤f≤30。
  7. 根据权利要求6所述的电化学装置，其满足0.2≤a/f≤2。
  8. 根据权利要求6所述的电化学装置，其中，所述电解液包括碳酸丙烯酯，基于所述电解液的总质量，所述碳酸丙烯酯的质量百分含量为g％，满足5≤g≤40。
  9. 根据权利要求1至8中任一项所述的电化学装置，其中，所述硅碳复合材料的制备方法包括以下步骤：
    (1)将多孔碳骨架置于硅烷气氛中进行第一沉积反应，其中，所述多孔碳骨架的孔体积为0.5ml/g至2.0ml/g，基于所述多孔碳骨架的孔体积，微孔和介孔的孔体积百分比为70％至90％；所述硅烷气氛中硅烷的体积百分比为1％至30％，所述第一沉积反应的温度为400℃至600℃、时间为1h至12h；
    (2)然后在氧气气氛中进行第二沉积反应得到硅碳复合材料，其中，所述氧气气氛中氧气的体积百分比为1％至30％，所述第二沉积反应的温度为400℃至800℃、时间为1h至12h。
  10. 根据权利要求1至9中任一项所述的电化学装置，其中所述电化学装置满足如下中 的至少一者：
    (1)所述a满足：6≤a≤15；
    (2)所述a/b满足：0.3≤a/b≤1；
    (3)所述b满足：18≤b≤30；
    (4)所述负极材料层的压实密度为1.4g/cm 3至1.8g/cm 3；
    (5)所述d满足：40≤d≤75；
    (6)所述e满足：40≤e≤75；
    (7)所述d/e满足：0.8≤d/e≤3；
    (8)所述硅碳复合材料中氧的质量百分含量为1％至6％；
    (9)所述多孔碳骨架的孔体积为0.8ml/g至2.0ml/g；
    (10)所述多孔碳骨架的微孔和介孔的孔体积百分比为80％至90％；
    (11)所述f满足：10≤f≤30；
    (12)所述a/f满足：0.2≤a/f≤1.5；
    (13)所述g满足：10≤g≤30。
  11. 一种电子装置，其包括权利要求1至10中任一项所述的电化学装置。
PCT/CN2022/121787 2021-12-31 2022-09-27 一种电化学装置和电子装置 WO2023124315A1 (zh)

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CN114420998A (zh) * 2021-12-31 2022-04-29 东莞新能源科技有限公司 一种电化学装置和电子装置
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106450161A (zh) * 2015-08-07 2017-02-22 Oci有限公司 二次电池用负极及其制备方法
CN206059513U (zh) * 2016-06-14 2017-03-29 奈克松有限公司 用于金属离子电池的电极
CN113169308A (zh) * 2018-11-08 2021-07-23 奈克松有限公司 用于金属离子电池的电活性材料
US20210313617A1 (en) * 2020-04-03 2021-10-07 Sila Nanotechnologies Inc. Lithium-ion battery with anode comprising blend of intercalation-type anode material and conversion-type anode material
US11174167B1 (en) * 2020-08-18 2021-11-16 Group14 Technologies, Inc. Silicon carbon composites comprising ultra low Z
CN114051663A (zh) * 2021-03-16 2022-02-15 宁德新能源科技有限公司 负极材料及其制备方法、电化学装置及电子装置
CN114420998A (zh) * 2021-12-31 2022-04-29 东莞新能源科技有限公司 一种电化学装置和电子装置

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106450161A (zh) * 2015-08-07 2017-02-22 Oci有限公司 二次电池用负极及其制备方法
CN206059513U (zh) * 2016-06-14 2017-03-29 奈克松有限公司 用于金属离子电池的电极
CN113169308A (zh) * 2018-11-08 2021-07-23 奈克松有限公司 用于金属离子电池的电活性材料
US20210313617A1 (en) * 2020-04-03 2021-10-07 Sila Nanotechnologies Inc. Lithium-ion battery with anode comprising blend of intercalation-type anode material and conversion-type anode material
US11174167B1 (en) * 2020-08-18 2021-11-16 Group14 Technologies, Inc. Silicon carbon composites comprising ultra low Z
CN114051663A (zh) * 2021-03-16 2022-02-15 宁德新能源科技有限公司 负极材料及其制备方法、电化学装置及电子装置
CN114420998A (zh) * 2021-12-31 2022-04-29 东莞新能源科技有限公司 一种电化学装置和电子装置

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