Active substance

Patent metadata

Field	Value
Publication number	US-9774032-B2
Application number	US-201414492558-A
Country	US
Kind code	B2
Filing date	Sep 22, 2014
Priority date	Sep 24, 2013
Publication date	Sep 26, 2017
Grant date	Sep 26, 2017

Abstract

According to one embodiment, there is provided an active substance. The active substance includes secondary particles and a carbon material phase formed on at least a part of a surface of each of the secondary particles. Each of the secondary particles is constructed by aggregated primary particles of an active material. The primary particles of the active material includes a niobium composite oxide represented by Li x M (1−y) Nb y Nb 2 O (7+δ) , wherein M is at least one selected from the group consisting of Ti and Zr, and x, y, and δ respectively satisfy 0≦x≦6, 0≦y≦1, and −1≦δ≦1. The secondary particles have a compression fracture strength of 10 MPa or more.

First claim

What is claimed is:

1. A negative electrode including an active substance, comprising:
secondary particles each of which is constructed by aggregated primary particles of an active material, the primary particles of the active material comprising a niobium composite oxide represented by Li x M (1−y) Nb y Nb 2 O (7+δ) , wherein M is at least one selected from the group consisting of Ti and Zr, and x, y, and δ respectively satisfy 0≦x≦6, 0≦y≦1, and −1≦δ≦1, the secondary particles having a compression fracture strength of 10 MPa or more and 200 MPa or less, an average particle diameter of the primary particles being in a range of 1 nm to 10 μm, and an average particle diameter of the secondary particles being in a range of 1 μm to 100 μm; and
a carbon material phase formed on at least a part of a surface of each of the secondary particles, a carbon content in the active substance being in a range of 0.1% by mass to 10% by mass based on a mass of the active substance.

2. The negative electrode according to claim 1 , wherein a carbon concentration in a central part of the active substance is lower than a carbon concentration in a surrounding part of the active substance.

3. The negative electrode according to claim 1 , wherein
the niobium composite oxide comprises at least one further element selected from boron and phosphorus; and
a content of the further element is in a range of 0.03% by mass to 3% by mass.

4. The negative electrode according to claim 1 , wherein a crystal structure of the niobium composite oxide belongs to a monoclinic system.

5. The negative electrode according to claim 1 , wherein a crystal structure of the niobium composite oxide belongs to a space group C2/m or P12/m1.

6. The negative electrode according to claim 1 , wherein the compression fracture strength is from 30 MPa to 200 MPa.

7. The negative electrode according to claim 1 , wherein the carbon content in the active substance is in a range of 1% by mass to 3% by mass based on the mass of the active substance.

8. The negative electrode according to claim 1 , wherein the average particle diameter of the secondary particles is in a range of 3 μm to 30 μm.

9. The negative electrode according to claim 1 , wherein the average particle diameter of the primary particles is in a range of 10 nm to 1 μm.

10. The negative electrode according to claim 1 , wherein the secondary particles have a specific surface area of 5 m 2 /g to 50 m 2 /g, the specific surface area being measured by the BET method.

11. An nonaqueous electrolyte battery comprising:
a positive electrode;
the negative electrode according to claim 1 ; and
a nonaqueous electrolyte.

12. A battery pack comprising the nonaqueous electrolyte battery according to claim 11 .

13. An automobile comprising the battery pack according to claim 12 .

14. A battery pack comprising a plurality of nonaqueous electrolyte batteries, each of the plurality of nonaqueous electrolyte batteries comprising: a positive electrode; the negative electrode according to claim 1 ; and a nonaqueous electrolyte, wherein
the plurality of nonaqueous electrolyte batteries are electrically connected to each other; and
the battery pack further comprises a protective circuit which can detect a voltage of each of the plurality of nonaqueous electrolyte batteries.

Assignees

• Toshiba Kk

Inventors

• Inagaki Hiroki
• Harada Yasuhiro
• Yoshida Yorikazu
• Ise Kazuki
• Takami Norio

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• C01P2006/12

  Surface area · CPC title

• Y02P70/54

  Cross-Sectional Technologies · mapped topic

• H01M10/052

  Li-accumulators · CPC title

• C01P2006/40

  Electric properties · CPC title