Binder for use in positive electrode for lithium ion secondary battery, positive electrode for lithium ion secondary battery containing said binder, lithium ion secondary battery using said positive electrode, and electrical machinery and apparatus

Patent metadata

Field	Value
Publication number	US-10164259-B2
Application number	US-201314432626-A
Country	US
Kind code	B2
Filing date	Oct 1, 2013
Priority date	Oct 12, 2012
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

This binder for use in a positive electrode for a lithium ion secondary battery contains a copolymer of both vinyl alcohol and an alkali-metal-neutralized ethylenically unsaturated carboxylic acid.

First claim

The invention claimed is:

1. A lithium ion secondary battery comprising:
a non-aqueous electrolyte; and
a positive electrode comprising:
an active material;
a conductive assistant; and
a binder comprising a random copolymer consisting of two copolymerized components, the two components being vinyl alcohol and an alkali metal-neutralized product of ethylene-unsaturated carboxylic acid,
wherein the random copolymer of vinyl alcohol and the alkali metal-neutralized product of ethylene-unsaturated carboxylic acid comprises a molar ratio of the vinyl alcohol to the alkali metal-neutralized product of ethylene-unsaturated carboxylic acid is 8/2 to 2/8.

2. An electric equipment comprising the lithium ion secondary battery of claim 1 .

3. The lithium ion secondary battery of claim 1 , wherein the binder is contained at equal to or greater than 0.5% by mass and equal to or less than 30% by mass with respect to a total mass of the active material, the conductive assistant, and the binder.

4. The lithium ion secondary battery of claim 1 , wherein a carbon nanotube is contained as the conductive assistant.

5. The lithium ion secondary battery of claim 4 , wherein a content of the carbon nanotube in the conductive assistant is at least one of equal to or greater than 30% by mass.

Assignees

• Aist
• Sumitomo Seika Chemicals

Inventors

• Mukai Takashi
• Morishita Masanori
• Sakai Tetsuo
• Kinpara Yuji
• Fujishige Junichi
• Fujimoto Nobutaka
• Karashima Shuichi

Classifications

• H01M4/622 Primary

  being polymers · CPC title

• C08F220/14

  Methyl esters {, e.g. methyl (meth)acrylate} · CPC title

• H01M4/136

  Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy · CPC title

• H01M4/366

  as layered products · CPC title

• C08F220/06

  Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof · CPC title