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EP-4738462-A1 - ANODE MATERIAL AND BATTERY

EP4738462A1EP 4738462 A1EP4738462 A1EP 4738462A1EP-4738462-A1

Abstract

The technical field relates to anode materials, an anode material and a battery being provided. The anode material includes a matrix material and a silicon material, and at least some of the silicon material is present in the matrix material, where the silicon material involves a first phase and a second phase, where the anode material is measured by a precession electron diffraction method that: based on a region with the silicon material present, a region with the silicon material in the first phase present has an area proportion A of A ≥70%, and a region with the silicon material in the second phase present has an area proportion B of 0<B≤30%. The anode material have low expansion, high capacity and excellent cycle performance.

Inventors

  • CHEN, XI
  • PANG, Chunlei
  • HE, Peng
  • Ren, Jianguo
  • HUANG, Youyuan
  • HE, XUEQIN

Assignees

  • BTR New Material Group Co., Ltd.

Dates

Publication Date
20260506
Application Date
20250923

Claims (15)

  1. An anode material, characterized in that the anode material comprises a matrix material and a silicon material, and at least some of the silicon material is present in the matrix material, wherein the silicon material involves a first phase and a second phase, wherein the anode material is measured by a precession electron diffraction method that: based on a region with the silicon material present, a region with the silicon material in the first phase present has an area proportion A of A ≥70%, and a region with the silicon material in the second phase present has an area proportion B of 0<B≤30%.
  2. The anode material according to claim 1, characterized in that the matrix material has pores, and at least some of the silicon material is present in the pores of the matrix material.
  3. The anode material according to claim 2, characterized in that an anode material with the silicon material removed satisfies at least one of the following features: (1) the anode material with the silicon material removed has micropores, wherein the micropores have a pore volume proportion of ≥80%; (2) the anode material with the silicon material removed has mesopores, wherein the mesopores have a pore volume proportion of ≤20%; (3) the anode material with the silicon material removed has macropores, wherein the macropores have a pore volume proportion of ≤1%; (4) the anode material with the silicon material removed has a total pore volume of 0.4 cm 3 /g to 1.5 cm 3 /g; (5) the anode material with the silicon material removed has a specific surface area of 200 m 2 /g to 3000 m 2 /g; and (6) in the anode material with the silicon material removed, pores with a pore size of 5 nm or less have a pore volume proportion of ≥90%.
  4. The anode material according to claim 1, characterized in that the matrix material comprises a carbon matrix, and the carbon matrix comprises one or more of artificial graphite, natural graphite, amorphous carbon, activated carbon, mesocarbon microbeads, carbon nanotubes, carbon nanofibers, and graphene.
  5. The anode material according to claim 1, characterized in that the matrix material comprises a non-carbon matrix, and the non-carbon matrix comprises at least one of a metal oxide, a silicide, a silicate, a phosphate, a titanate, and an aluminum borate.
  6. The anode material according to any one of claims 1 to 5, characterized in that in an XRD pattern of the anode material, the anode material has a diffraction peak at 28.4°±0.5°, and the silicon material has a grain size c of ≤1 nm.
  7. The anode material according to any one of claims 1 to 5, characterized in that the anode material satisfies at least one of the following features: (1) the anode material has a total pore volume of 0.001 cm 3 /g to 0.1 cm 3 /g; (2) the pores of the anode material have a mean pore size of 0.4 nm to 50 nm; (3) the anode material contains micropores, wherein the micropores have a pore volume proportion of ≤10%; (4) the anode material contains mesopores, wherein the mesopores have a pore volume proportion of ≥80%; (5) the anode material contains macropores, wherein the macropores have a pore volume proportion of ≤20%; and (6) the anode material contains micropores and mesopores, wherein a ratio of a pore volume of the micropores and a pore volume of the mesopores is (1 to 50):(50 to 99).
  8. The anode material according to any one of claims 1 to 5, characterized in that an anode slurry prepared from the anode material has an average gas production of ≤1 mL/g for 1 day at 25°C.
  9. The anode material according to any one of claims 1 to 5, characterized in that the anode material satisfies at least one of the following features: (1) the anode material has a median particle size D 50 of 5 µm to 20 µm; and (2) the anode material has a particle size distribution satisfying 0.9≤(D 90 -D 10 )/D 50 ≤5;(3) the anode material has a specific surface area of 0.5 m 2 /g to 10 m 2 /g.
  10. The anode material according to any one of claims 1 to 5, characterized in that the anode material has a compaction density of 0.8 g/cm 3 to 1.3 g/cm 3 .
  11. The anode material according to any one of claims 1 to 5, characterized in that the anode material has a tap density of 0.5 g/cm 3 to 1.5 g/cm 3 .
  12. The anode material according to any one of claims 1 to 5, characterized in that the anode material has a powder conductivity of 0.1 S/cm to 2 S/cm under a pressure of 20 kN.
  13. The anode material according to any one of claims 1 to 5, characterized in that the anode material contains silicon element accounting for a mass percentage of 20% to 60%.
  14. The anode material according to any one of claims 1 to 5, characterized in that the anode material has a specific surface area of 0.5 m 2 /g to 10 m 2 /g.
  15. A battery, characterized in that the battery comprises the anode material according to any one of claims 1 to 14.

Description

TECHNICAL FIELD The present disclosure relates to the technical field of an anode material, in particular to an anode material and a battery. BACKGROUND Lithium-ion batteries have the advantages of high energy density, long service life, no environmental pollution, and the like, and have been widely applied in the field of 3C. With the development of the market, the lithium-ion battery is not only widely applied in mobile devices, such as smart phones and portable computers, but also in the field of large-scale devices, such as electric vehicles and electric tools. In order to improve energy density of the battery, the research and development of a silicon-based anode material become increasingly mature. The silicon-based material has a large volume expansion during charging and discharging, which tends to cause particles to pulverize and then spall from current collector. In addition, the volume of the silicon-based material varies repeatedly during electrochemical cycling, so that solid electrolyte membrane formed on surface of the silicon-based material is continuously damaged and regenerated, resulting in continuous consumption of lithium ions, which affects stability of the silicon-based material. The battery capacity is rapidly reduced during a long cycling. Therefore, there is an urgent problem to be solved at present, namely how to improve the volume expansion of the silicon-based anode material, and enhance structural stability and cycle stability of the anode material. SUMMARY In some embodiments, an anode material and a battery are provided, where volume expansion of the anode material is improved, and structural stability and cycle stability of the anode material are both enhanced. In a first aspect, an anode material is provided. The anode material includes a matrix material and a silicon material, and at least some of the silicon material is present in the matrix material, where the silicon material involves a first phase and a second phase; where the anode material is measured by a precession electron diffraction method that:based on a region with the silicon material present, a region with the silicon material in the first phase present has an area proportion A of A ≥70%, and a region with the silicon material in the second phase present has an area proportion B of 0<B≤30%. In some embodiments, the matrix material has pores, and at least some of the silicon material is present in the pores of the matrix material. In some embodiments, an anode material with the silicon material removed has micropores, where the micropores have a pore volume proportion of ≥80%. In some embodiments, an anode material with the silicon material removed has mesopores, where the mesopores have a pore volume proportion of ≤20%. In some embodiments, an anode material with the silicon material removed has macropores, where the macropores have a pore volume proportion of ≤1%. In some embodiments, the anode material with the silicon material removed has a total pore volume of 0.4 cm3/g to 1.5 cm3/g. In some embodiments, the anode material with the silicon material removed has a specific surface area of 200 m2/g to 3000 m2/g; In some embodiments, in the anode material with the silicon material removed, pores with a pore size of 5 nm or less have a pore volume proportion of ≥90%. In some embodiments, the matrix material includes a carbon matrix, and the carbon matrix includes one or more of artificial graphite, natural graphite, amorphous carbon, activated carbon, mesocarbon microbeads, carbon nanotubes, carbon nanofibers, and graphene. In some embodiments, the matrix material includes a non-carbon matrix, and the non-carbon matrix includes at least one of a metal oxide, a silicide, a silicate, a phosphate, a titanate, and an aluminum borate. In some embodiments, in an XRD pattern of the anode material, the anode material has a diffraction peak at 28.4°±0.5°, and the silicon material has a grain size c of ≤1 nm. In some embodiments, the anode material has a total pore volume of 0.001 cm3/g to 0.1 cm3/g. In some embodiments, the pores of the anode material have a mean pore size of 0.4 nm to 50 nm. In some embodiments, the anode material contains micropores, where the micropores have a pore volume proportion of ≤10%. In some embodiments, the anode material contains mesopores, where the mesopores have a pore volume proportion of ≥80%. In some embodiments, the anode material contains macropores, where the macropores have a pore volume proportion of ≤20%. In some embodiments, an anode slurry prepared from the anode material has an average gas production of ≤1 mL/g for 1 day at 25°C. In some embodiments, the anode material has a median particle size D50 of 5 µm to 20 µm. In some embodiments, the anode material has a particle size distribution satisfying 0.9≤(D90-D10)/D50≤5. In some embodiments, the anode material has a specific surface area of 0.5 m2/g to 10 m2/g. In some embodiments, the anode material has a compaction density