# US 12,002,946 B2 · Non-aqueous electrolyte secondary battery

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- Number: US 12,002,946 B2
- Document ID: US12002946B2
- Status: Granted
- Kind: B2
- Application number: 17/265,263
- Filed: 2019-08-02
- Published: 2021-10-07
- Granted: 2024-06-04
- Earliest claimed: 2018-08-07
- Assignees: Panasonic Holdings Corporation; Panasonic Energy Co., Ltd.
- Applicants: Panasonic Corporation; SANYO Electric Co., Ltd.
- Inventors: Shunsuke Nambuya; Yuto Horiuchi; Shimpei Yamagami
- Web page: https://patentgrep.com/patent/US12002946B2

## CPC

- H01M 4/364: {as mixtures}
- 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 4/131: Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
- H01M 4/134: Electrodes based on metals, Si or alloys
- H01M 4/386: {Silicon or alloys based on silicon}
- H01M 4/5825: {Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines}
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M 10/0566: Liquid materials
- 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
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A nonaqueous electrolyte secondary battery includes a positive electrode, a negative electrode, and an electrolyte liquid. The negative electrode includes a negative electrode mixture layer containing a first negative electrode active material and a negative electrode collector to which the negative electrode mixture layer is adhered. The first negative electrode active material contains a first lithium silicate phase containing lithium, silicon, and oxygen and first silicon particles dispersed in the first lithium silicate phase. An atomic ratio A1:O/Si of the oxygen to the silicon in the first lithium silicate phase satisfies a relationship of 2<A1≤3. At a surface side of the negative electrode, an existence ratio of the first negative electrode active material in the negative electrode mixture layer is high as compared to that at a negative electrode collector side of the negative electrode.

## Claims

### Claim 1

A nonaqueous electrolyte secondary battery comprising: a positive electrode; a negative electrode; and an electrolyte liquid,
wherein the negative electrode includes a negative electrode mixture layer containing a first negative electrode active material and a negative electrode collector to which the negative electrode mixture layer is adhered, the first negative electrode active material contains a first lithium silicate phase containing lithium, silicon, and oxygen and first silicon particles dispersed in the first lithium silicate phase,
an atomic ratio A1:O/Si of the oxygen to the silicon in the first lithium silicate phase satisfies a relationship of 2<A1≤3, and
in a thickness direction from an outer surface of the negative electrode mixture layer to an inner surface of the negative electrode mixture layer contacting the negative electrode current collector, an existence ratio of the first negative electrode active material in the outer surface of the negative electrode mixture layer is higher as compared to that at the inner surface.

### Claim 2 (depends on 1)

The nonaqueous electrolyte secondary battery according to claim 1,
wherein, when a ½ region of the negative electrode mixture layer from the outer surface is regarded as a first region, and a ½ region of the negative electrode mixture layer from the inner surface is regarded as a second region,
a content M1A of the first negative electrode active material in the first region and a content M1B of the first negative electrode active material in the second region satisfy a relationship of 0≤M1B/M1A<1.

### Claim 3 (depends on 2)

The nonaqueous electrolyte secondary battery according to claim 2,
wherein the second region of the negative electrode mixture layer contains at least a second negative electrode active material,
the second negative electrode active material contains a second lithium silicate phase containing lithium, silicon, and oxygen and second silicon particles dispersed in the second lithium silicate phase, and
an atomic ratio A2:O/Si of the oxygen to the silicon in the second lithium silicate phase satisfies a relationship of 3<A2≤4.

### Claim 4 (depends on 3)

The nonaqueous electrolyte secondary battery according to claim 3,
wherein the first region and the second region each contain the first negative electrode active material and the second active material, and
a mass ratio MA of the first negative electrode active material to the total of the first negative electrode active material and the second negative electrode active material in the first region is high as compared to a mass ratio MB of the first negative electrode active material to the total of the first negative electrode active material and the second negative electrode active material in the second region.

### Claim 5 (depends on 4)

The nonaqueous electrolyte secondary battery according to claim 4,
wherein the first lithium silicate phase has a composition represented by a formula: Li2SixO2x+1, and the x satisfies a relationship of 1≤x≤2, and
the second lithium silicate phase has a composition represented by a formula: Li2SiyO2y+1, and they satisfies a relationship of ½≤y<1.

### Claim 6 (depends on 5)

The nonaqueous electrolyte secondary battery according to claim 5,
wherein the mass ratio MA is 0.65 to 0.71, and
the mass ratio MB is 0.50 to 0.61.

### Claim 7 (depends on 2)

The nonaqueous electrolyte secondary battery according to claim 2,
wherein, before a first charge, the second region of the negative electrode mixture layer contains at least a precursor of the second negative electrode active material,
the precursor of the second negative electrode active material has a composition represented by a formula: SiOz, and
the z satisfies a relationship of 0.5≤z≤1.5.

### Claim 8 (depends on 1)

The nonaqueous electrolyte secondary battery according to claim 1,
wherein the first silicon particles in the first negative electrode active material has a content of 50 to 80 percent by mass.