Anode material, preparation method thereof, and lithium ion battery

Patent metadata

Field	Value
Publication number	US-2025006900-A1
Application number	US-202318546769-A
Country	US
Kind code	A1
Filing date	Feb 10, 2023
Priority date	Apr 22, 2022
Publication date	Jan 2, 2025
Grant date	—

Abstract

An anode material, a preparation method thereof, and a lithium ion battery provided. The anode material includes a core of a silicon-based material and a first coating layer coating on at least part of surface of the core of the silicon-based material, where first coating layer has an undulation y of 1≥y≥0.10, and the undulation y of the first coating layer is expressed by Formula (I):y=1-exp⁢(-(Rmax-Rmin)D⁢50×C)(I)where, Rmax is a maximum thickness (nm) of the first coating layer, Rmin is a minimum thickness (nm) of the first coating layer, D50 is a median particle size (μm) of the anode material, and C is a mass ratio (%) of the first coating layer in the anode material. The anode material of the present disclosure has properties of excellent conductivity, cycling performance, and rate performance, and can suppress occurrence of irreversible expansion.

First claim

1 . An anode material, comprising a core of a silicon-based material and a first coating layer coated on at least a surface of the core, wherein the first coating layer has an undulation y of 1≥y≥0.10, and the undulation y of the first coating layer is expressed by Formula (I):

y
=

1
-

exp
⁢

(

-

(

R
max

-

R
min

)

D
⁢
50

×
C

)

(
I
)

in Formula (I), R max is a maximum thickness (nm) of the first coating layer, R min is a minimum thickness (nm) of the first coating layer, D50 is a median particle size (μm) of the anode material, and C is a mass ratio (%) of the first coating layer in the anode material.

2 . The anode material of claim 1 , wherein the anode material comprises at least one of the following features (1) to (7):
(1) the core of the silicon-based material comprises crystalline silicon and silicide, and the silicide comprises at least one of SiO x , silicon dioxide, silicate, and silicon alloy, wherein 1.5≥x≥0.5; (2) the core of the silicon-based material comprises crystalline silicon and silicide, and the silicide comprises at least one of SiO x , silicon dioxide, silicate, and silicon alloy, wherein 1.5≥x≥0.5, and the crystalline silicon has a grain size D Si of 2.5 nm to 15 nm; (3) the core of the silicon-based material comprises crystalline silicon and silicide, and the silicide comprises at least one of SiO x , silicon dioxide, silicate, and silicon alloy, wherein 1.5≥x≥0.5, and a grain size of the crystalline silicon is D Si , a grain size of the silicate is D silicate , and D silicate /D Si =0.3 to 5.0; (4) the core of the silicon-based material comprises crystalline silicon and silicide, and the silicide comprises at least one of SiO x , silicon dioxide, silicate, and silicon alloy, wherein 1.5≥x≥0.5, and a grain size of the crystalline silicon is D Si , a grain size of the silicon alloy is D silicon alloy , and D silicon alloy /D Si =0 to 2.0; (5) the core of the silicon-based material comprises crystalline silicon and silicide, and the silicide comprises at least one of SiO x , silicon dioxide, silicate, and silicon alloy, wherein 1.5≥x≥0.5, and the silicon alloy comprises at least one of silicon-iron alloy, silicon-silver alloy, silicon-nickel alloy, silicon-cobalt alloy, silicon-manganese alloy, silicon-indium alloy, silicon-rhodium alloy, silicon-ruthenium alloy, silicon-iridium alloy, silicon-platinum alloy, silicon-titanium alloy, and silicon-molybdenum alloy; (6) the core of the silicon-based material comprises crystalline silicon and silicide, and the silicide comprises at least one of SiO x , silicon dioxide, silicate, and silicon alloy, wherein 1.5≥x≥0.5, and a cation of the silicate comprises a metal element; and (7) the core of the silicon-based material has a median particle size of 1 μm to 13 μm.

3 . The anode material of claim 1 , wherein the anode material comprises at least one of the following features (1) to (8):
(1) the first coating layer comprises a carbon layer, and a material of the carbon layer comprises at least one of amorphous carbon, graphite, soft carbon, and hard carbon; (2) the first coating layer comprises an organic polymer material layer, and a material of the organic polymer material layer comprises at least one of polyamine compound, polyester compound, and polyolefin compound; (3) a surface morphology of the first coating layer comprises at least one of petal shape, stripe shape, cone shape, and granular shape; (4) the first coating layer has a thickness of 10 nm to 500 nm; (5) the first coating layer has pores with a pore diameter of 10 nm to 60 nm; (6) the first coating layer has a porosity of 0.5% to 15%; (7) the core of the silicon-based material comprises a first dopant element, and the first dopant element comprises at least one of lithium, magnesium, sodium, copper, platinum, iron, manganese, cobalt, nickel, indium, silver, gold, titanium, molybdenum, aluminum, palladium, calcium, iridium, chromium, gallium, rhodium, and ruthenium; and (8) the first coating layer comprises a second dopant element, and the second dopant element comprises at least one of nitrogen, fluorine, phosphorus, sulfur, and boron.

4 . The anode material of claim 1 , wherein a second coating layer is further provided between the core of the silicon-based material and the first coating layer.

5 . The anode material of claim 4 , wherein the second coating layer comprises at least one of the following features ( 1 ) to ( 3 ):
(1) a material of the second coating layer comprises silicon alloy; (2) a material of the second coating layer comprises silicon alloy, and the silicon alloy comprises at least one of silicon-iron alloy, silicon-silver alloy, silicon-nickel alloy, silicon-cobalt alloy, silicon-manganese alloy, silicon-indium alloy, silicon-rhodium alloy, silicon-ruthenium alloy, silicon-iridium alloy, silicon-platinum alloy, silicon-titanium alloy, and silicon-molybdenum alloy; and (3) the second coating layer has a thickness of 0 nm to 10 nm but excluding 0 nm.

6 . The anode material of claim 1 , wherein the anode material comprises at least one of the following features (1) to (5):
(1) in a Raman spectrum of the anode material measured by a Raman spectroscopy, a ratio of a strongest peak intensity I 1 of the anode material at 1300 cm −1 to 1400 cm −1 to a strongest peak intensity I 2 of the anode material at 1550 cm −1 to 1650 cm −1 satisfying 0<I 1 /I 2 <3, and a ratio of a strongest peak intensity I 3 of the anode material at 480 cm −1 to 540 cm −1 to the strongest peak intensity I 1 of the anode material at 1300 cm −1 to 1400 cm −1 satisfying 1<I 3 /I 1 <4.5; (2) the anode material has a median particle size D50 of 1.5 μm to 15 μm; (3) the anode material has a carbon content of 0.5% to 10%; (4) the anode material has a powder conductivity of 0.1 S/m to 100 S/m; and (5) the anode material has a specific surface area of 0.8 m 2 /g to 10 m 2 /g.

7 . A preparation method of an anode material, comprising:
mixing an organic carbon source, a silicon-based material, and an organic solvent to obtain a precursor; and subj

Assignees

• Btr New Mat Group Co Ltd
• Dingyuan New Energy Tech Co Ltd
• Huizhou Btr New Material Tech Co Ltd

Inventors

• Xie Wei
• Pang Chunlei
• Deng Zhiqiang
• Ren Jianguo
• He Xueqin

Classifications

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• H01M4/626

  Metals · CPC title

• H01M4/48

  of inorganic oxides or hydroxides · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M2004/021

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