# US 12,183,919 B2 · Silicon-oxygen composite negative electrode material and method for preparation thereof and lithium-ion battery

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- Number: US 12,183,919 B2
- Document ID: US12183919B2
- Status: Granted
- Kind: B2
- Application number: 17/420,570
- Filed: 2020-10-28
- Published: 2022-04-14
- Granted: 2024-12-31
- Earliest claimed: 2019-10-30
- Assignees: Btr New Material Group Co., Ltd.
- Applicants: Btr New Material Group Co., Ltd.
- Inventors: Chunlei Pang; Lijuan Qu; Zhiqiang Deng; Jianguo Ren; Xueqin He
- Web page: https://patentgrep.com/patent/US12183919B2

## CPC

- C01B 33/113: Silicon oxides; Hydrates thereof {(preparing monoxide by reduction of siliceous material C01B33/182)}
- H01M 4/48: of inorganic oxides or hydroxides
- C01B 33/18: Preparation of finely divided silica neither in sol nor in gel form; After-treatment thereof (preparation of aerogels by dehydrating gels C01B33/158; treatment to enhance the pigmenting or filling properties C09C)
- H01M 4/0471: {involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis}
- H01M 4/131: Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
- H01M 4/1391: of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
- H01M 4/362: {Composites}
- H01M 4/366: {as layered products}
- H01M 4/483: {for non-aqueous cells (H01M4/485 takes precedence)}
- H01M 4/485: of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence)
- H01M 4/625: {Carbon or graphite}
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M 2004/021: {Physical characteristics, e.g. porosity, surface area}
- H01M 2004/027: {Negative electrodes}
- Y02E 60/10: Energy storage using batteries
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

The present application provides a silicon-oxygen composite negative electrode material and method for preparation thereof and lithium-ion battery. The silicon-oxygen composite negative electrode material comprises a silicon-oxygen composite negative electrode material comprising SiOx, non-Li2Si2O5 lithium-containing compound, and Li2Si2O5; said Li2Si2O5 is coated on the surface of the non-Li2Si2O5 lithium-containing compound; 0≤x≤1.2. The preparation method comprises: mixing a first silicon source with a reducing lithium source and roasting, to obtain a composite material containing a non-Li2Si2O5 lithium-containing compound; the composite material containing the non-Li2Si2O5 lithium-containing compound is fused with a second silicon source and then subjected to heat treatment to obtain a silicon-oxygen composite negative electrode material. The silicon-oxygen composite anode material provided by the present application is coated with Li2Si2O5, solving the problem in the prior art of a negative electrode material producing strong alkaline or easily soluble by-products in water after pre-lithiation and affecting subsequent processing.

## Claims

### Claim 1

A silicon-oxygen composite negative electrode material, comprising SiOx, a non-Li2Si2O5 lithium-containing compound and Li2Si2O5, wherein the Li2Si2O5 covers a surface of the non-Li2Si2O5 lithium-containing compound, wherein 0≤x≤1.2, and the silicon-oxygen composite negative electrode material has a pH value of 7<pH<11, and the Li2Si2O5 has a thickness of 100 nm to 5000 nm.

### Claim 2 (depends on 1)

The silicon-oxygen composite negative electrode material according to claim 1, wherein the silicon-oxygen composite negative electrode material satisfies at least one of following definitions a to e:
a. the non-Li2Si2O5 lithium-containing compound comprises at least one of an oxide of lithium, a halide of lithium, a hydroxide of lithium, a lithium-containing alloy, a carbonate of lithium, a silicate of lithium and an acetate of lithium;
b. a content by mass percent of an oxygen element in the SiOx gradually decreases from a surface of SiOx particles to an interior of the particles;
c. the SiOx is located inside the non-Li2Si2O5 lithium-containing compound;
d. a mass ratio of the SiOx to the non-Li2Si2O5 lithium-containing compound is 1:1.5 to 1:4.3; and
e. the silicon-oxygen composite negative electrode material has an average particle size of 4 μm to 10 μm.

### Claim 3 (depends on 2)

The silicon-oxygen composite negative electrode material according to claim 2, wherein the silicon-oxygen composite negative electrode material satisfies at least one of following definitions a to c:
a. a carbon layer is further formed on a surface of the silicon-oxygen composite negative electrode material;
b. a carbon layer is further formed on a surface of the silicon-oxygen composite negative electrode material, wherein the carbon layer has a thickness of 10 nm to 2000 nm; and
c. a carbon layer is further formed on a surface of the silicon-oxygen composite negative electrode material, wherein the carbon layer has a coating rate of 60% to 100%.

### Claim 4 (depends on 1)

The silicon-oxygen composite negative electrode material according to claim 1, wherein the silicon-oxygen composite negative electrode material satisfies at least one of following definitions a to c:
a. a carbon layer is further formed on a surface of the silicon-oxygen composite negative electrode material;
b. a carbon layer is further formed on a surface of the silicon-oxygen composite negative electrode material, wherein the carbon layer has a thickness of 10 nm to 2000 nm; and
c. a carbon layer is further formed on a surface of the silicon-oxygen composite negative electrode material, wherein the carbon layer has a coating rate of 60% to 100%.

### Claim 5

A lithium-ion battery, comprising a composite negative electrode material, wherein the composite negative electrode material comprises SiOx, a non-Li2Si2O5 lithium-containing compound and Li2Si2O5, wherein the Li2Si2O5 covers a surface of the non-Li2Si2O5 lithium-containing compound, wherein 0≤x≤1.2, wherein the silicon-oxygen composite negative electrode material has a pH value of 7<pH<11, and the Li2Si2O5 has a thickness of 100 nm to 5000 nm; or
wherein the composite negative electrode material is prepared by a method for preparing a silicon-oxygen composite negative electrode material, comprising steps of:
mixing a first silicon source SiOy with a reductive lithium source and roasting a mixture, so as to obtain a composite material, wherein the composite material comprises a non-Li2Si2O5 lithium-containing compound, wherein 0<y<2; and
fusing the composite material with a second silicon source and then performing a heat treatment, so as to obtain the silicon-oxygen composite negative electrode material, wherein the silicon-oxygen composite negative electrode material comprises SiOx, the non-Li2Si2O5 lithium-containing compound and Li2Si2O5, wherein the Li2Si2O5 covers a surface of the non-Li2Si2O5 lithium-containing compound, wherein 0≤x≤1.2, wherein the silicon-oxygen composite negative electrode material has a pH value of 7<pH<11, and the Li2Si2O5 has a thickness of 100 nm to 5000 nm.

### Claim 6

A method for preparing a silicon-oxygen composite negative electrode material, comprising steps of:
mixing a first silicon source SiOy with a reductive lithium source and roasting a mixture, so as to obtain a composite material, wherein the composite material comprises a non-Li2Si2O5 lithium-containing compound, wherein 0<y<2; and
fusing the composite material with a second silicon source and then performing a heat treatment, so as to obtain the silicon-oxygen composite negative electrode material, wherein the silicon-oxygen composite negative electrode material comprises SiOx, the non-Li2Si2O5 lithium-containing compound and Li2Si2O5, wherein the Li2Si2O5 covers a surface of the non-Li2Si2O5 lithium-containing compound, wherein 0≤x≤1.2, wherein the silicon-oxygen composite negative electrode material has a pH value of 7<pH<11, and the Li2Si2O5 has a thickness of 100 nm to 5000 nm.

### Claim 7 (depends on 6)

The method according to claim 6, wherein the silicon-oxygen composite negative electrode material satisfies at least one of following definitions a to d:
a. a content by mass percent of an oxygen element in the SiOx gradually decreases from a surface of SiOx particles to an interior of the particles;
b. the SiOx is located inside the non-Li2Si2O5 lithium-containing compound;
c. a mass ratio of the SiOx to the non-Li2Si2O5 lithium-containing compound is 1:1.5 to 1:4.3; and
d. the silicon-oxygen composite negative electrode material has an average particle size of 4 μm to 10 μm.

### Claim 8 (depends on 7)

The method according to claim 7, wherein the method satisfies at least one of following definitions a to e:
a. the reductive lithium source comprises at least one of lithium hydride, lithium alkyl, lithium metal, lithium aluminum hydride, lithium amide, and lithium borohydride;
b. the first silicon source is SiO;
c. a mass ratio of the first silicon source to the reductive lithium source is 1:0.03 to 1:0.4;
d. the first silicon source has a particle size D10 greater than 1.0 μm and Dmax less than 50 μm; and
e. the non-Li2Si2O5 lithium-containing compound comprises at least one of an oxide of lithium, a halide of lithium, a hydroxide of lithium, a lithium-containing alloy, a carbonate of lithium, a silicate of lithium and an acetate of lithium.

### Claim 9 (depends on 7)

The method according to claim 7, further comprising:
cooling and sieving the composite material obtained by the roasting so that the composite material has an average particle size of 2 μm to 9 μm.

### Claim 10 (depends on 7)

The method according to claim 7, wherein the method satisfies at least one of following definitions a to c:
a. the second silicon source comprises silicon dioxide;
b. the second silicon source comprises nanoscale silicon dioxide; and
c. a mass ratio of the composite material to the second silicon source is 1:0.1 to 1:3.

### Claim 11 (depends on 6)

The method according to claim 6, wherein the method satisfies at least one of following definitions a to e:
a. the reductive lithium source comprises at least one of lithium hydride, lithium alkyl, lithium metal, lithium aluminum hydride, lithium amide, and lithium borohydride;
b. the first silicon source is SiO;
c. a mass ratio of the first silicon source to the reductive lithium source is 1:0.03 to 1:0.4;
d. the first silicon source has a particle size D10 greater than 1.0 μm and Dmax less than 50 μm; and
e. the non-Li2Si2O5 lithium-containing compound comprises at least one of an oxide of lithium, a halide of lithium, a hydroxide of lithium, a lithium-containing alloy, a carbonate of lithium, a silicate of lithium and an acetate of lithium.

### Claim 12 (depends on 11)

The method according to claim 11, wherein the method satisfies at least one of following definitions a to c:
a. the roasting is performed in a non-oxidizing atmosphere, wherein the non-oxidizing atmosphere comprises at least one of hydrogen, nitrogen, helium, neon, argon, krypton, and xenon;
b. the roasting is performed at a temperature of 300° C. to 1000° C.; and
c. the roasting is performed for a duration of 1 h to 8 h.

### Claim 13 (depends on 6)

The method according to claim 6, further comprising:
cooling and sieving the composite material obtained by the roasting so that the composite material has an average particle size of 2 μm to 9 μm.

### Claim 14 (depends on 6)

The method according to claim 6, wherein the method satisfies at least one of following definitions a to c:
a. the second silicon source comprises silicon dioxide;
b. the second silicon source comprises nanoscale silicon dioxide; and
c. a mass ratio of the composite material to the second silicon source is 1:0.1 to 1:3.

### Claim 15 (depends on 14)

The method according to claim 14, wherein the method satisfies at least one of following definitions a to c:
a. the heat treatment is performed at a temperature of 300° C. to 600° C.;
b. the heat treatment is performed at a heating rate less than 2° C./min; and
c. the heat treatment is performed for a duration of 0.5 h to 4 h.

### Claim 16 (depends on 6)

The method according to claim 6, further comprising, before the mixing a first silicon source SiOy with a reductive lithium source,
heating and gasifying raw materials of an oxide of silicon in a protective atmosphere or in vacuum, so as to produce a gas of the oxide of silicon, and cooling and shaping a resultant to obtain particles of the first silicon source SiOy, wherein 0<y<2.

### Claim 17 (depends on 16)

The method according to claim 16, wherein the method satisfies at least one of following definitions a to d:
a. the raw materials of the oxide of silicon comprise Si and SiO2;
b. the heating is performed at a temperature of 900° C. to 1300° C.;
c. the shaping comprises at least one of crushing, ball milling and classification; and
d. the particles of the first silicon source SiOy have a D10 greater than 1.0 μm and a Dmax less than 50 μm.

### Claim 18 (depends on 6)

The method according to claim 6, further comprising:
coating, using carbon, a material to be coated by carbon, wherein the material to be coated by carbon comprises at least one of the first silicon source and the silicon-oxygen composite negative electrode material.

### Claim 19 (depends on 18)

The method according to claim 18, wherein the method satisfies at least one of following definitions a to c:
a. the coating using carbon comprises at least one of gas-phase carbon coating and solid-phase carbon coating;
b. the coating using carbon comprises at least one of gas-phase carbon coating and solid-phase carbon coating, wherein the gas-phase carbon coating is performed at a condition where the material to be coated by carbon is heated up to 600° C. to 1000° C. in a presence of a protective atmosphere, an organic carbon source gas is introduced, a temperature is maintained for 0.5 h to 10 h and then a resultant is cooled, wherein the organic carbon source gas comprises a hydrocarbon, and the hydrocarbon comprises at least one of methane, ethylene, acetylene, and benzene; and
c. the coating using carbon comprises at least one of gas-phase carbon coating and solid-phase carbon coating, wherein the solid-phase carbon coating is performed at a condition where the material to be coated by carbon is fused with a carbon source for 0.5 h to 2 h and then an obtained carbon mixture is carbonized at 600° C. to 1000° C. for 2 h to 6 h and cooled, wherein the carbon source comprises at least one of polymers, saccharides, organic acids and asphalt.

### Claim 20 (depends on 6)

The method according to claim 6, comprising steps of:
mixing SiO with a reductive lithium source in a mass ratio of 1:0.03 to 1:0.4, roasting a mixture in a presence of a non-oxidizing atmosphere at a roasting temperature of 450° C. to 800° C. for a roasting duration of 1 h to 8 h, and then cooling and sieving a resultant, so as to obtain a composite material, wherein the composite material comprises a non-Li2Si2O5 lithium-containing compound; and
fusing the composite material with SiO2 in a mass ratio of 1:0.1 to 1:3 and then performing a heat treatment at 300° C. to 600° C. for a heat treatment duration of 0.5 h to 4 h, so as to obtain the silicon-oxygen composite negative electrode material, wherein the heat treatment is performed at a heating rate less than 2° C./min,
wherein the method further comprises coating, using carbon, at least one of the SiO and the silicon-oxygen composite negative electrode material, wherein the coating with carbon comprises at least one of gas-phase carbon coating and solid-phase carbon coating.