Negative electrode active material for electrical device, and electrical device including the same

Patent metadata

Field	Value
Publication number	US-10651465-B2
Application number	US-201616309416-A
Country	US
Kind code	B2
Filing date	Jun 16, 2016
Priority date	Jun 16, 2016
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

A negative electrode active material including a silicon-containing alloy having a ternary alloy composition expressed by Si—Sn—Ti and including a structure in which an a-Si phase containing amorphous or low-crystalline silicon formed by dissolving tin in a crystal structure of silicon is dispersed in a parent phase of a silicide phase including TiSi2, wherein when a peak intensity of a Si—O bond peak that is observed at a position where an interatomic distance in a radial wave function observed by XAFS is 0.13 nm is S(1) and a peak intensity of a Si—Si bond peak that is observed at a position where the interatomic distance is 0.2 nm is S(2), a relation of S(2)>S(1) is satisfied is used for an electrical device. When used, the negative electrode active material achieves both cycle durability and charging-discharging efficiency for an electrical device such as a lithium ion secondary battery.

First claim

The invention claimed is:

1. A negative electrode active material for an electrical device, comprising:
a silicon-containing alloy including a structure in which a phase mainly containing amorphous or low-crystalline silicon formed by dissolving tin in a crystal structure of silicon is dispersed in a parent phase of a silicide phase including TiSi 2 , and having a composition expressed by:
Si x Sn y Ti z A a

wherein A represents an inevitable impurity, x, y, z, and a represent values in mass %, and 0<x<100, 0<y<100, 0<z<100, and 0≤a<0.5, and x+y+z+a=100 are satisfied, and wherein, when a peak intensity of a Si—O bond peak that is observed at a position where an interatomic distance in a radial wave function observed by XAFS is 0.13 nm is S(1) and a peak intensity of a Si—Si bond peak that is observed at a position where the interatomic distance is 0.2 nm is S(2), a relation of S(2)>S(1) is satisfied.

2. The negative electrode active material for an electrical device according to claim 1 , wherein a peak intensity ratio of S(1) to S(2) that is expressed by S(1)/S(2) is less than 0.5.

3. The negative electrode active material for an electrical device according to claim 1 , wherein when a peak intensity of a Si—Ti bond peak that is observed at a position where the interatomic distance in the radial wave function observed by XAFS is 0.28 nm is S(3), a relation of S(2)>S(3)>S(1) is further satisfied.

4. The negative electrode active material for an electrical device according to claim 3 , wherein a peak intensity ratio of S(3) to S(2) that is expressed by S(3)/S(2) is more than 0.31.

5. A negative electrode for an electrical device, comprising the negative electrode active material for an electrical device according to claim 1 .

6. An electrical device comprising the negative electrode for an electrical device according to claim 5 .

Assignees

• Nissan Motor

Inventors

• Yoshioka Youichi
• Chiba Nobutaka
• Watanabe Manabu
• Arai Masaya

Classifications

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• C01P2002/80

  defined by measured data other than those specified in group C01P2002/70 · CPC title

• H01M4/386 Primary

  Silicon or alloys based on silicon · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• C22C28/00 Primary

  Alloys based on a metal not provided for in groups C22C5/00 - C22C27/00 · CPC title