# US 10,312,507 B2 · Negative-electrode active material for non-aqueous electrolyte secondary battery, and non-aqueous electrolyte secondary battery

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- Number: US 10,312,507 B2
- Document ID: US10312507B2
- Status: Granted
- Kind: B2
- Application number: 15/524,030
- Filed: 2016-01-18
- Published: 2017-11-16
- Granted: 2019-06-04
- Earliest claimed: 2015-01-28
- Assignees: Sanyo Electric Co., Ltd.
- Applicants: Sanyo Electric Co., Ltd.
- Inventors: Tatsuya Akira; Yoshio Kato; Hiroshi Minami; Taizou Sunano
- Web page: https://patentgrep.com/patent/US10312507B2

## CPC

- H01M 4/364: {as mixtures}
- C01B 33/32: Alkali metal silicates ({C01B33/24} , C01B33/26 take precedence)
- 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 4/625: {Carbon or graphite}
- H01M 4/366: {as layered products}
- 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}
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

The initial charge/discharge efficiency and cycle characteristics of a non-aqueous electrolyte secondary battery that contains a silicon material as a negative-electrode active material are improved. A negative-electrode active material particle (10) according to an embodiment includes a lithium silicate phase (11) represented by Li2zSiO(2+z) {0<z<2} and silicon particles (12) dispersed in the lithium silicate phase (11). A lithium silicate constituting the lithium silicate phase has a crystallite size of 40 nm or less. The crystallite size is calculated using the Scherrer equation from the half-width of a diffraction peak of a (111) plane of the lithium silicate in an XRD pattern obtained by XRD measurement of the negative-electrode active material particle 10.

## Claims

### Claim 1

A negative-electrode active material for a non-aqueous electrolyte secondary battery, comprising:
a lithium silicate phase represented by Li2z,SiO(2+z) {0<z <2} and
silicon particles dispersed in the lithium silicate phase,
wherein a lithium silicate constituting the lithium silicate phase has a crystallite size of 40 nm or less when calculated using a Scherrer equation from a half-width of a diffraction peak of a (111) plane of the lithium silicate in an XRD pattern obtained by XRD measurement,
wherein the negative-electrode active material for the non-aqueous electrolyte secondary battery after charging and discharging contains no Li4SiO4.

### Claim 2 (depends on 1)

The negative-electrode active material for a non-aqueous electrolyte secondary battery according to claim 1, wherein the Si (111) plane has a higher diffraction peak intensity than a (111) plane of the lithium silicate in the XRD pattern obtained by XRD measurement.

### Claim 3 (depends on 1)

The negative-electrode active material for a non-aqueous electrolyte secondary battery according to claim 1, wherein no diffraction peak of SiO2 is observed at 2θ=25 degrees in the XRD pattern.

### Claim 4 (depends on 2)

The negative-electrode active material for a non-aqueous electrolyte secondary battery according to claim 2, wherein no diffraction peak of SiO2 is observed at 2θ=25 degrees in the XRD pattern.

### Claim 5 (depends on 1)

The negative-electrode active material for a non-aqueous electrolyte secondary battery according to claim 1, wherein the lithium silicate phase is composed mainly of Li2Si2O5, and a diffraction peak of a (111) plane of the Li2Si2O5 in the XRD pattern has a half-width of 0.09 degrees or more.

### Claim 6 (depends on 2)

The negative-electrode active material for a non-aqueous electrolyte secondary battery according to claim 2, wherein the lithium silicate phase is composed mainly of Li2Si2O5, and a diffraction peak of a (111) plane of the Li2Si2O5 in the XRD pattern has a half-width of 0.09 degrees or more.

### Claim 7 (depends on 3)

The negative-electrode active material for a non-aqueous electrolyte secondary battery according to claim 3, wherein the lithium silicate phase is composed mainly of Li2Si2O5, and a diffraction peak of a (111) plane of the Li2Si2O5 in the XRD pattern has a half-width of 0.09 degrees or more.

### Claim 8 (depends on 4)

The negative-electrode active material for a non-aqueous electrolyte secondary battery according to claim 4, wherein the lithium silicate phase is composed mainly of Li2Si2O5, and a diffraction peak of a (111) plane of the Li2Si2O5 in the XRD pattern has a half-width of 0.09 degrees or more.

### Claim 9 (depends on 1)

The negative-electrode active material for a non-aqueous electrolyte secondary battery according to claim 1, wherein the diffraction peak of the (111) plane of a lithium silicate in the XRD pattern obtained by XRD measurement has a half-width of 0.05 degrees or more.

### Claim 10 (depends on 1)

The negative-electrode active material for a non-aqueous electrolyte secondary battery according to claim 1, wherein the lithium silicate phase is composed mainly of Li2SiO3, and a diffraction peak of a (111) plane of the Li2SiO3 in the XRD pattern has a half-width of 0.10 degrees or more.

### Claim 11 (depends on 1)

The negative-electrode active material for a non-aqueous electrolyte secondary battery according to claim 1, wherein the lithium silicate phase and the silicon particles constitute a base particle, and the base particle is covered with an electrically conductive layer.

### Claim 12 (depends on 1)

A non-aqueous electrolyte secondary battery comprising: a negative electrode containing the negative-electrode active material for a non-aqueous electrolyte secondary battery according to claim 1; a positive electrode; and a non-aqueous electrolyte.

### Claim 13 (depends on 7)

A non-aqueous electrolyte secondary battery comprising: a negative electrode containing the negative-electrode active material for a non-aqueous electrolyte secondary battery according to claim 7; a positive electrode; and a non-aqueous electrolyte.