Electrode for battery and production method thereof, nonaqueous electrolyte battery, battery pack, and active material

Patent metadata

Field	Value
Publication number	US-9698411-B2
Application number	US-201313969146-A
Country	US
Kind code	B2
Filing date	Aug 16, 2013
Priority date	Feb 17, 2011
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

According to one embodiment, there is provided an electrode for battery which includes a current collector and an active material layer provided on the current collector. The active material layer contains particles of a lithium titanate compound having a spinel structure and a basic polymer. Here, the basic polymer is coating at least a part of the surface of the particles of the lithium titanate compound.

First claim

What is claimed is:

1. An electrode, comprising a current collector and an active material layer on the current collector,
wherein the active material layer comprises a particle of lithium titanate compound having a spinel structure, a layer of polybenzimidazole, and a mixed layer comprising a cellulose ether compound and a copolymer rubber,
the layer of polybenzimidazole coats a surface of the particle of lithium titanate compound, and
the mixed layer coats the layer of polybenzimidazole.

2. A nonaqueous electrolyte battery comprising:
the electrode according to claim 1 as a negative electrode;
a positive electrode; and
a nonaqueous electrolyte.

3. A battery pack, comprising the nonaqueous electrolyte battery according to claim 2 and a container accommodating the nonaqueous electrolyte battery.

4. A method of producing an electrode, comprising:
dispersing a particle of lithium titanate compound having a spinel structure in a solution comprising a polybenzimidazole to prepare a first dispersion liquid comprising the particle of lithium titanate compound and the polybenzimidazole;
separating the particle of lithium titanate compound attached with the polybenzimidazole from the first dispersion liquid and drying to obtain the particle of lithium titanate compound coated with a layer of the polybenzimidazole;
adding the particle of lithium titanate compound coated with the layer of polybenzimidazole to a dispersion solvent to prepare a second dispersion liquid comprising the particle of lithium titanate compound coated with the layer of polybenzimidazole;
adding a cellulose ether compound and a copolymer rubber to the second dispersion liquid to prepare a slurry comprising the particle of lithium titanate compound coated with the layer of polybenzimidazole, the cellulose ether compound and the copolymer rubber; and
applying the slurry on a surface of a current collector and drying to form an active material layer,
wherein the active material layer comprises the particle of lithium titanate compound, coated with the layer of polybenzimidazole, which is coated with a mixed layer of the cellulose ether compound and the copolymer rubber.

5. The electrode according to claim 1 , wherein the active material layer comprises the cellulose ether compound in an amount from 0.5% by mass to 5% by mass, relative to a total mass of lithium titanate compound contained in the active material layer.

6. The electrode according to claim 1 , wherein the active material layer comprises the copolymer rubber in an amount from 0.5% by mass to 10% by mass, relative to a total mass of lithium titanate compound contained in the active material layer.

7. The electrode according to claim 1 , wherein a molecular weight of the polybenzimidazole is from 100 to 100,000.

8. The electrode according to claim 1 , wherein a molecular weight of the polybenzimidazole is from 500 to 5,000.

9. The electrode according to claim 1 , wherein a ratio of an amount of the layer of polybenzimidazole to an amount of the particle of lithium titanate compound is from 0.01% by mass to 0.03% by mass.

10. The electrode according to claim 9 , wherein
the cellulose ether compound is carboxymethyl cellulose, and
the copolymer rubber is selected from the group consisting of styrene-butadiene copolymer rubber and polyvinylidene fluoride.

Assignees

• Toshiba Kk

Inventors

• Yamamoto Dai
• Iwasaki Takuya
• Harada Yasuhiro
• Inagaki Hiroki
• Satake Hideki

Classifications

• H01M4/0404

  by coating on electrode collectors · CPC title

• H01M4/131 Primary

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• H01M4/366

  as layered products · CPC title

• H01M4/622

  being polymers · CPC title