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CN-122000312-A - Battery monomer, negative electrode material, preparation method of negative electrode material, battery device and power utilization device

CN122000312ACN 122000312 ACN122000312 ACN 122000312ACN-122000312-A

Abstract

The application provides a battery monomer, a negative electrode material, a method for preparing the negative electrode material, a battery device and an electric device. The battery unit comprises a negative electrode plate, wherein the negative electrode plate comprises a negative electrode material, the negative electrode material comprises a negative electrode active material, the negative electrode active material comprises secondary particles, the secondary particles comprise primary particles and one-dimensional carbon materials and/or two-dimensional carbon materials, the volume average particle size Dv50 of the secondary particles is 7-23 mu m, the volume average particle size Dv50 of the primary particles is 0.5-5 mu m, the primary particles comprise porous carbon materials, and silicon particles are distributed on the surfaces and/or in pore channels of the porous carbon materials. The battery monomer has high energy density, and simultaneously has good dynamic performance and stable cycle performance.

Inventors

  • WU KAI
  • SUN XIN
  • YUN LIANG

Assignees

  • 宁德时代新能源科技股份有限公司

Dates

Publication Date
20260508
Application Date
20241108

Claims (20)

  1. 1. The battery monomer comprises a negative electrode plate, wherein the negative electrode plate comprises a negative electrode material, the negative electrode material comprises a negative electrode active material, the negative electrode active material comprises secondary particles, the secondary particles comprise primary particles and one-dimensional carbon materials and/or two-dimensional carbon materials, the volume average particle size Dv50 of the secondary particles is 7-23 mu m, the volume average particle size Dv50 of the primary particles is 0.5-5 mu m, the primary particles comprise porous carbon materials, and silicon particles are distributed on the surfaces and/or in pore channels of the porous carbon materials.
  2. 2. The battery cell of claim 1, wherein one or more of the following: The secondary particles have a (Dv 90-Dv 10)/Dv 50 value of 0.8-1.9 or 1.1-1.8; the average pore diameter of the anode material is 2-10nm or 3.8-9nm; The pore volume of the anode material is 0.7-1.6cm 3 /g or 1.05-1.6cm 3 /g; The BET specific surface area of the anode material is 9-70m 2 /g or 9-20m 2 /g.
  3. 3. The battery cell according to claim 1 or 2, characterized by one or more of the following: the primary particles have a (Dv 90-Dv 10)/Dv 50 value of 3.4-5; the BET specific surface area of the porous carbon material is 800-2000m 2 /g or 1000-2000m 2 /g; the average pore diameter of the porous carbon material is 0.8-5nm; The pore volume of the porous carbon material is 0.3-1.05cm 3 /g or 0.6-1.05cm 3 /g.
  4. 4. The battery cell according to any one of claim 1 to 3, wherein, When the secondary particles include one-dimensional carbon material, the one-dimensional carbon material is entangled with the primary particles, or, When the secondary particles include a one-dimensional carbon material and a two-dimensional carbon material, the one-dimensional carbon material is entangled with the primary particles and/or the two-dimensional carbon material.
  5. 5. The battery cell according to any one of claims 1 to 4, wherein, The one-dimensional carbon material comprises one or more of carbon nano tubes, carbon nano fibers, linear carbon and carbon nano rods, and/or, The two-dimensional carbon material includes graphene.
  6. 6. The battery cell of claim 5, wherein one or more of the following: The mass content of silicon element in the anode material is 30% -60%; The two-dimensional carbon material comprises graphene, wherein the average diameter of a lamellar of the graphene is 3-8 mu m; The two-dimensional carbon material comprises graphene, wherein the average number of sheets of the graphene is 1-8; the one-dimensional carbon material comprises carbon nanotubes, and the length-diameter ratio of the carbon nanotubes is 3000-10000; The surface of the primary particles is also coated with a coating layer, and the coating layer contains carbon; The average thickness of the primary particle surface coating layer is more than 0 and less than or equal to 5nm.
  7. 7. The battery cell according to any one of claims 1 to 6, wherein a mass ratio of the primary particles to the two-dimensional carbon material is 1 (0.1-0.5), and/or, The mass ratio of the primary particles to the one-dimensional carbon material is 1 (0.001-0.015).
  8. 8. The battery cell according to any one of claims 1 to 7, the surface of the secondary particle is coated with a coating layer including carbon.
  9. 9. The battery cell according to claim 8, wherein the average thickness of the coating layer of the secondary particle surface is 2-10nm.
  10. 10. A negative electrode material comprises a negative electrode active material, wherein the negative electrode active material comprises secondary particles, the secondary particles comprise primary particles and one-dimensional carbon materials and/or two-dimensional carbon materials, the volume average particle diameter Dv50 of the secondary particles is 7-23 mu m, the volume average particle diameter Dv50 of the primary particles is 0.5-5 mu m, the primary particles comprise porous carbon materials, and silicon particles are distributed on the surfaces and/or in pore channels of the porous carbon materials.
  11. 11. The anode material according to claim 10, characterized by one or more of the following: The secondary particles have a (Dv 90-Dv 10)/Dv 50 value of 0.8-1.9 or 1.1-1.8; the average pore diameter of the anode material is 2-10nm or 3.8-9nm; The pore volume of the anode material is 0.7-1.6cm 3 /g or 1.05-1.6cm 3 /g; The BET specific surface area of the anode material is 9-70m 2 /g or 9-20m 2 /g.
  12. 12. The anode material according to claim 10 or 11, characterized by one or more of the following: the primary particles have a (Dv 90-Dv 10)/Dv 50 value of 3.4-5; the BET specific surface area of the porous carbon material is 800-2000m 2 /g or 1000-2000m 2 /g; the average pore diameter of the porous carbon material is 0.8-5nm; The pore volume of the porous carbon material is 0.3-1.05cm 3 /g or 0.6-1.05cm 3 /g.
  13. 13. The negative electrode material according to any one of claims 10 to 12, wherein, When the secondary particles include one-dimensional carbon material, the one-dimensional carbon material is entangled with the primary particles, or, When the secondary particles include a one-dimensional carbon material and a two-dimensional carbon material, the one-dimensional carbon material is entangled with the primary particles and/or the two-dimensional carbon material.
  14. 14. The negative electrode material according to any one of claims 10 to 13, wherein, The one-dimensional carbon material comprises one or more of carbon nano tubes, carbon nano fibers, linear carbon and carbon nano rods, and/or, The two-dimensional carbon material includes graphene.
  15. 15. The anode material according to any one of claims 10 to 14, characterized by one or more of the following: The mass content of silicon element in the anode material is 30% -60%; The two-dimensional carbon material comprises graphene, wherein the average diameter of a lamellar of the graphene is 3-8 mu m; The two-dimensional carbon material comprises graphene, wherein the average number of sheets of the graphene is 1-8; the one-dimensional carbon material comprises carbon nanotubes, and the length-diameter ratio of the carbon nanotubes is 3000-10000; The surface of the primary particles is also coated with a coating layer, and the coating layer contains carbon; The average thickness of the primary particle surface coating layer is more than 0 and less than or equal to 5nm.
  16. 16. The negative electrode material according to any one of claims 10 to 15, wherein a mass ratio of the primary particles to the two-dimensional carbon material is 1 (0.1-0.5), and/or, The mass ratio of the primary particles to the one-dimensional carbon material is 1 (0.001-0.015).
  17. 17. The anode material according to any one of claims 10 to 16, the surface of the secondary particles is coated with a coating layer, the coating layer including carbon.
  18. 18. The negative electrode material according to claim 17, wherein an average thickness of the coating layer on the surface of the secondary particles is 2-10nm.
  19. 19. A method of preparing a negative electrode material comprising the steps of: Mixing primary particles, a one-dimensional carbon material and/or a two-dimensional carbon material with a solvent, granulating, and roasting for the first time to obtain a negative electrode material, wherein the primary particles comprise porous carbon materials and silicon particles distributed on the surface and/or in pore channels of the porous carbon materials, the negative electrode material comprises a negative electrode active material, the negative electrode active material comprises secondary particles, the volume average particle diameter Dv50 of the secondary particles is 7-23 mu m, and the volume average particle diameter Dv50 of the primary particles is 0.5-5 mu m.
  20. 20. The method of claim 19, wherein one or more of the following: the mass ratio of the primary particles to the two-dimensional carbon material is 1 (0.1-0.5); the mass ratio of the primary particles to the one-dimensional carbon material is 1 (0.001-0.015); the temperature of the mixing is 70-90 ℃; The temperature of the first roasting is 400-650 ℃; The time of the first roasting is 4-9h; the first calcination is carried out in an inert atmosphere; the anode material is an anode material according to any one of claims 10 to 18.

Description

Battery monomer, negative electrode material, preparation method of negative electrode material, battery device and power utilization device Technical Field The application relates to the technical field of batteries, in particular to a battery monomer, a negative electrode material, a method for preparing the negative electrode material, a battery device and an electric device. Background In recent years, as the application range of the battery is wider and wider, the battery is widely applied to energy storage power supply systems such as hydraulic power, firepower, wind power, solar power stations and the like, and a plurality of fields such as electric tools, electric bicycles, electric motorcycles, electric automobiles, military equipment, aerospace and the like. As batteries have been greatly developed, higher demands are also being made on energy density, cycle performance, and kinetic performance. Disclosure of Invention The present application has been made in view of the above problems, and an object thereof is to provide a battery cell, a negative electrode material, a method for producing a negative electrode material, a battery device, and an electric device. The battery monomer has high energy density, and simultaneously has good dynamic performance and stable cycle performance. In order to achieve the above object, a first aspect of the present application provides a battery cell, comprising a negative electrode sheet, the negative electrode sheet comprising a negative electrode material, the negative electrode material comprising a negative electrode active material, the negative electrode active material comprising secondary particles, the secondary particles comprising primary particles, and one-dimensional carbon material and/or two-dimensional carbon material, the volume average particle diameter Dv50 of the secondary particles being 7-23 μm, the volume average particle diameter Dv50 of the primary particles being 0.5-5 μm, the primary particles comprising porous carbon material, and silicon particles being distributed on the surface and/or in pores of the porous carbon material. The application shortens the solid phase mass transfer distance of lithium ions by adopting primary particles with a certain particle size on the premise of keeping the particle size of secondary particles of the anode material, improves the energy density of the battery monomer by adopting the porous carbon material surface and/or silicon particles in pore channels in the primary particles, and simultaneously provides space for the volume expansion of silicon by adopting the two-dimensional carbon material and/or the one-dimensional carbon material, stabilizes the material structure, improves the material conductivity, reduces the DCR of the battery monomer, thereby improving the energy density, the dynamic performance and the cycle stability of the battery monomer. In any embodiment, the secondary particles have a (Dv 90-Dv 10)/Dv 50 value of 0.8 to 1.9 or 1.1 to 1.8. Therefore, the uniformity of the particle size of the secondary particles is improved, and the tap density of the anode material is improved, so that the dynamic performance and the energy density of the battery cell are improved. In any embodiment, the average pore size of the negative electrode material is 2 to 10nm or 3.8 to 9nm. Therefore, the method is beneficial to improving the deposition amount of silicon and the transmission of lithium ions, and simultaneously controlling the expansion degree caused by silicon, so that the energy density, the dynamic performance and the cycling stability of the battery cell are improved. In any embodiment, the pore volume of the negative electrode material is 0.7-1.6cm 3/g or 1.05-1.6cm 3/g. Therefore, the method is beneficial to improving the deposition amount of silicon and the transmission of lithium ions, controlling the expansion degree caused by silicon, and improving the energy density, the dynamic performance and the cycling stability of the battery monomer. In any embodiment, the negative electrode material has a BET specific surface area of 9 to 70m 2/g or 9 to 20m 2/g. Thus, the BET specific surface area of the anode material affects the pore volume and average pore diameter of the anode material, thereby improving the energy density, dynamic performance and cycle stability of the battery cell. In any embodiment, the primary particles have a (Dv 90-Dv 10)/Dv 50 value of 3.4-5. Therefore, the primary particles have uniform particle size, the solid phase mass transfer distance of lithium ions is shortened, and the primary particles expose more reactive sites, so that the DCR of the battery monomer is reduced, and the dynamic performance of the battery monomer is improved. In any embodiment, the porous carbon material has a BET specific surface area of 800-2000m 2/g or 1000-2000m 2/g. In any embodiment, the porous carbon material has an average pore size of 0.8 to 5nm. In any embodiment, the poro