Nonaqueous electrolyte secondary battery and method of manufacturing the same, and separator for nonaqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-9806315-B2
Application number	US-201514831306-A
Country	US
Kind code	B2
Filing date	Aug 20, 2015
Priority date	Aug 21, 2014
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

A method of manufacturing a nonaqueous electrolyte secondary battery includes: preparing a separator substrate; forming a porous layer, which contains at least a fluorophosphate and a binder, on a surface of the separator substrate; preparing an electrode body by laminating a positive electrode and a negative electrode to face each other with a separator including the porous layer interposed therebetween, in which the separator is arranged such that the porous layer faces the positive electrode; preparing a battery assembly including the electrode body and a nonaqueous electrolyte; and charging the battery assembly at least once.

First claim

What is claimed is:

1. A method of manufacturing a nonaqueous electrolyte secondary battery, the method comprising:
preparing a separator substrate;
preparing a separator by applying a paste or a slurry composition, which contains at least a fluorophosphate and a binder kneaded with each other in a solvent, to a surface of the separator substrate to form a porous layer on the surface of the separator substrate;
preparing an electrode body by arranging the separator such that the porous layer faces a positive electrode and laminating the positive electrode and a negative electrode to face each other with the separator interposed therebetween;
preparing a battery assembly comprising the electrode body and a nonaqueous electrolyte; and
charging the battery assembly at least once.

2. The method according to claim 1 , wherein
the separator is prepared by preparing the composition further containing an inorganic filler and applying the composition to the separator substrate.

3. The method according to claim 1 , wherein
lithium difluorophosphate is used as the fluorophosphate.

4. The method according to claim 1 , wherein
an amount of the fluorophosphate and an amount of the nonaqueous electrolyte in the composition are adjusted such that a concentration of the fluorophosphate in the porous layer in terms of a concentration of the nonaqueous electrolyte is 0.05 mol/kg or more.

5. The method according to claim 1 , wherein
the nonaqueous electrolyte does not contain the fluorophosphate.

6. The method according to claim 1 , wherein the fluorophosphate is fixed on the porous layer.

Assignees

• Toyota Motor Co Ltd

Inventors

• Takeda Kazuhisa

Classifications

• H01M10/058 Primary

  Construction or manufacture · CPC title

• H01M50/457

  comprising three or more layers · CPC title

• H01M50/431

  Inorganic material · CPC title

• H01M50/451

  comprising layers of only organic material and layers containing inorganic material · CPC title

• H01M50/417

  Polyolefins · CPC title