Negative electrode material and non-aqueous electrolyte secondary battery

• US 11,196,040 B2
• Filed: 11/17/2017
• Issued: 12/07/2021
• Est. Priority Date: 11/30/2016
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Inventors: Uchiyama, Yohei, Yamamoto, Taisuke, Akira, Tatsuya, Yamamoto, Norihisa, Minami, Hiroshi
• Primary Examiner(s): Laios, Maria
• Assistant Examiner(s): Hornsby, Bartholomew A
• Application Number:
  US16/464,817
• Publication Number:
  US 20190319261A1
• Time in Patent Office: 1,481 Days
• CPC Class Codes: H01M 2004/027 Negative electrodes
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/364 as mixtures
• CPC Class Codes: H01M 4/366 as layered products
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 4/5825 Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
• CPC Class Codes: H01M 4/625 Carbon or graphite
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Disclosed is a negative electrode material including: a lithium silicate phase that contains a lithium silicate; and silicon particles that are dispersed in the lithium silicate phase, wherein the silicon particles have a crystallite size of 10 nm or more, and the lithium silicate has a composition represented by the following formula: Li₂Si₂O₅.(x−2)SiO₂, where 2<x≤18 is satisfied.

Claims

1. A negative electrode active material comprising:

a lithium silicate phase; and

silicon particles that are dispersed in the lithium silicate phase,

wherein the silicon particles have a crystallite size of 10 nm or more,

the lithium silicate phase has a composition represented by the following formula;

Li₂Si₂O₅⋅

(x−

2)SiO₂, where 2<

x≤

18 is satisfied, and

wherein the negative electrode active material is a particulate material.

2. The negative electrode active material in accordance with claim 1,

wherein 2.1≤

x≤

18 is satisfied.

3. The negative electrode active material in accordance with claim 1,

wherein 3≤

x≤

8 is satisfied.

4. The negative electrode active material in accordance with claim 1,

wherein the lithium silicate phase and the silicon particles form the particulate material, and the particulate material that has an average particle size of 1 to 25 μ

m.

5. The negative electrode active material in accordance with claim 4, comprising

a conductive material that covers at least a portion of a surface of the particulate material.

6. The negative electrode active material in accordance with claim 1,

wherein the silicon particles have an average particle size of 500 nm or less.

7. The negative electrode active material in accordance with claim 6,

wherein the silicon particles have an average particle size of 200 nm or less.

8. A non-aqueous electrolyte secondary battery comprising:

a negative electrode that includes the negative electrode active material in accordance with claim 1 and a binder;

a positive electrode that is capable of electrochemically absorbing and desorbing lithium; and

a non-aqueous electrolyte.