# US 12,009,515 B2 · Negative electrode active material for lithium secondary battery and preparation method thereof

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,009,515 B2
- Document ID: US12009515B2
- Status: Granted
- Kind: B2
- Application number: 16/764,641
- Filed: 2018-11-22
- Published: 2020-12-24
- Granted: 2024-06-11
- Earliest claimed: 2017-11-24
- Assignees: LG Energy Solution, Ltd.
- Applicants: LG Chem, Ltd.
- Inventors: Yong Ju Lee; Rae Hwan Jo; Su Min Lee; Dong Hyuk Kim; Se Mi Park
- Web page: https://patentgrep.com/patent/US12009515B2

## CPC

- 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)
- C01B 33/113: Silicon oxides; Hydrates thereof {(preparing monoxide by reduction of siliceous material C01B33/182)}
- C01B 33/22: Magnesium silicates
- C01B 33/32: Alkali metal silicates ({C01B33/24} , C01B33/26 take precedence)
- 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 4/366: {as layered products}
- 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
- C01P 2002/02: Amorphous compounds
- C01P 2004/80: Particles consisting of a mixture of two or more inorganic phases
- C01P 2006/40: Electric properties
- H01M 2004/027: {Negative electrodes}
- Y02E 60/10: Energy storage using batteries
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A negative electrode active material for a lithium secondary battery, which includes a silicon-based particle represented by M-SiOx, wherein M is Li, Mg, Ca, Al, or Ti, and 0≤x<2, wherein the M-SiOx includes an amorphous phase at 20 wt % to 70 wt % based upon a total weight of the M-SiOx, thereby exhibiting excellent initial efficiency and lifespan characteristics, and a preparation method thereof.

## Claims

### Claim 1

A negative electrode active material for a lithium secondary battery, comprising:
a silicon-based particle represented by M-SiOx, wherein the M is Mg, and O≤x<2; and
a carbon coating layer on a surface of the silicon-based particle;
wherein the M-SiOx, comprises a crystalline phase and an amorphous phase,
wherein the amorphous phase is present in an amount of 37 wt % to 52 wt % based upon a total weight of the M-SiOx,
wherein the silicon-based particle comprises the M in an amount of 10 wt % to 20 wt % based on a total weight of the M SiOx, and
wherein the carbon coating layer is included in an amount of 4 wt % to 5 wt % based on a total weight of the negative electrode active material.

### Claim 2 (depends on 1)

The negative electrode active material of claim 1, wherein the crystalline phase comprises one or more selected from the group consisting of a Si phase, a SiO2 phase, a metal oxide phase, and a metal silicate phase.

### Claim 3 (depends on 1)

A negative electrode for a lithium secondary battery comprising the negative electrode active material according to claim 1.

### Claim 4 (depends on 3)

A lithium secondary battery comprising the negative electrode according to claim 3.

### Claim 5 (depends on 1)

A method of preparing the negative electrode active material according to claim 1, the method comprising:
vacuum-heating a powder mixture of Si and SiO2 to form SiOx vapor,
wherein 0≤x<2;
vacuum-heating a metal M to form M vapor, wherein the M is Mg;
mixing the SiOx vapor and the M vapor to form a mixture;
solid-phase condensing the mixture of SiOx vapor and the M vapor to form the M-SiOx; and forming the carbon coating layer on the surface of the M-SiOx after solid-phase condensing the mixture of SiOx vapor and the M vapor,
wherein the solid-phase condensing process comprises a step of controlling a temperature to adjust an amorphous phase content of the M-SiOx to a range of 37 wt % to 52 wt % based upon a total weight of the M-SiOx,
wherein the silicon-based particle comprises M present in an amount of 10 wt % to 20 wt % based on a total weight of the silicon-based particle, and
wherein the carbon coating layer is included in an amount of 4 wt % to 5 wt % based on a total weight of the negative electrode active material.

### Claim 6 (depends on 5)

The method of claim 5, wherein the temperature in the solid-phase condensing process is controlled in a range of 340° C. to 810° C.

### Claim 7 (depends on 5)

The method of claim 5, wherein the temperature in the solid-phase condensing process is controlled in a range of 400° C. to 750° C.

### Claim 8 (depends on 5)

The method of claim 5, wherein the carbon coating layer is formed by carbonizing a carbon precursor.