Anode material, preparation method thereof and battery

Patent metadata

Field	Value
Publication number	US-12451489-B2
Application number	US-202519206435-A
Country	US
Kind code	B2
Filing date	May 13, 2025
Priority date	Sep 30, 2024
Publication date	Oct 21, 2025
Grant date	Oct 21, 2025

Abstract

Anode material, preparation method thereof, and battery. Anode material includes graphite and carbon layer located on at least part of surface of graphite. Particle surface and particle section of anode material are respectively tested by Raman spectroscopy, peak area ratio of D characteristic peak within range of 1300 cm −1 to 1350 cm −1 to G characteristic peak within range of 1500 cm −1 to 1580 cm −1 is I D /I G , ratio of I D /I G measured on the particle surface is A, and ratio of I D /I G measured on particle section is B, and 1.22<A-B≤2.10. Particle surface of anode material is tested by adopting atomic force microscopy, 1 μm×1 μm test region is randomly selected on particle surface of anode material, arithmetic average value of height deviation absolute values relative to reference surface in test region is S nm, where 15 nm≤S≤60 nm. Anode material improves lithium-ion transport kinetics, initial Coulombic efficiency, and cycle performance.

First claim

What is claimed is:

1. An anode material for a lithium ion battery comprising graphite and a carbon layer located on at least part of a surface of the graphite; wherein the carbon layer comprises amorphous carbon, and a thickness of the carbon layer is 15 nm to 250 nm;
wherein, when a particle surface and a particle section of the anode material are respectively tested by Raman spectroscopy, a peak area ratio of D characteristic peak within a range of 1300 cm −1 to 1350 cm −1 to G characteristic peak within a range of 1500 cm −1 to 1580 cm −1 is I D /I G , a ratio of I D /I G measured on the particle surface of the anode material is A, and a ratio of I D /I G measured on the particle section of the anode material is B, where 1.70≤A≤3.00, 0.47≤B≤0.8, and 1.22<A-B≤2.10; and
wherein, when the particle surface of the anode material is tested by an atomic force microscopy, and a 1 μm×1 μm test region is randomly selected on the particle surface of the anode material, an arithmetic average value of height deviation absolute values relative to a reference surface in the test region is S nm, where 15 nm≤S≤60 nm, S=1/n Σ i=1 n |Z|, n≥5, n≥5, and Z is a height deviation value of any test point in the test region relative to the reference surface;
wherein a median particle size of the anode material is 4 μm to 25 μm, and a specific surface area of the anode material is ≤6 μm 2 /g.

2. The anode material for the lithium ion battery according to claim 1 , wherein the anode material satisfies at least one of following features:
1) the graphite comprises at least one of artificial graphite, natural graphite and microcrystalline graphite;
2) a fixed carbon content of the graphite is ≥95%.

3. The anode material for the lithium ion battery according to claim 1 , wherein a tap density of the anode material is in a range of 0.75 g/cm 3 to 1.3 g/cm 3 .

4. The anode material for the lithium ion battery according to claim 1 , wherein an oil absorption value of the anode material is in a range of 38 mL/100 g to 48 mL/100 g.

5. A lithium ion battery comprising the anode material for the lithium ion battery according to claim 1 .

6. A method for preparing the anode material for the lithium ion battery according to claim 1 , comprising following steps:
dispersing a coating agent with an active group and a reaction regulator in an aqueous solution, and performing a pre-polymerization reaction to obtain a pre-polymerization solution, wherein a polymerization degree of a polymer in the pre-polymerization solution is 3 to 30;
adding graphite into the pre-polymerization solution for liquid phase coating, and performing solid-liquid separation to obtain a precursor, wherein a solid-liquid ratio of the graphite to the pre-polymerization solution is 1:(1.3 to 3.5), and a mass ratio of the graphite to the coating agent is 100:(4 to 30); and
carbonizing the precursor to obtain an anode material.

7. The method for preparing the anode material for the lithium ion battery according to claim 6 , wherein the method satisfies at least one of following features:
(1) the active group comprises at least one of a carbon-carbon double bond, a carboxyl group, a hydroxyl group and an amine group;
(2) the reaction regulator comprises at least one of a redox agent and a pH regulator;
(3) the reaction regulator comprises a redox agent, and a mass ratio of the redox agent to the coating agent is 1:(0.7 to 2.0);
(4) the pre-polymerization reaction is performed for 1 h to 4 h;
(5) the liquid phase coating is performed for 4 h to 24 h; and
(6) the coating agent with the active group comprises at least one of styrene, fluorostyrene, bromostyrene, aminostyrene, phenylacetic acid, phenylpropionic acid, aniline, phenylenediamine, acrylic acid, methyl acrylate, ethyl acrylate, phenyl acrylate, benzyl acrylate, acrylamide, methylacrylamide, ethylacrylamide, phenylacrylamide, maleic acid, maleic anhydride, maleic diamine, citric acid, mesaconic acid, itaconic acid, itaconic anhydride, sulfamic acid, ammonium sulfamate, benzoic acid, ammonium benzoate, and p-fluorobenzoic acid.

8. The method for preparing the anode material for the lithium ion battery according to claim 6 , wherein the method satisfies at least one of the following features:
(1) a temperature of the carbonization treatment is 1000° C. to 2300° C.;
(2) a heat preservation time of the carbonization treatment is 0.5 h to 6 h; and
(3) the carbonization treatment is performed under a protective atmosphere.

Assignees

• Btr New Mat Group Co Ltd

Inventors

• Dong Hang
• Zhang Daofu
• Zhou Haihui
• He Peng
• Ren Jianguo
• Huang Youyuan
• He Xueqin

Classifications

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M4/0471

  involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis · CPC title

• H01M4/625

  Carbon or graphite · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title