Nonaqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-2017229743-A1
Application number	US-201515501272-A
Country	US
Kind code	A1
Filing date	Aug 3, 2015
Priority date	Aug 6, 2014
Publication date	Aug 10, 2017
Grant date	—

Abstract

A nonaqueous electrolyte secondary battery includes an electrode body 80 in which a positive electrode ( 10 ) and a negative electrode ( 20 ) are disposed to be opposite to each other with a separator ( 40 ) interposed between the positive electrode and the negative electrode; a nonaqueous electrolyte; and a battery case that accommodates the electrode body and the nonaqueous electrolyte. The battery case includes a current interrupt device that operates in response to an increase in an internal pressure of the battery case. The nonaqueous electrolyte contains a fluorine-containing compound and a gas producing agent. The separator ( 40 ) includes a hydrofluoric acid trapping layer ( 44 ) containing an inorganic phosphate compound on a surface of the separator.

First claim

I what is claimed is:

1 . A nonaqueous electrolyte secondary battery comprising:
an electrode body in which a positive electrode and a negative electrode are disposed to be opposite to each other with a separator interposed between the positive electrode and the negative electrode; a nonaqueous electrolyte; and a battery case that accommodates the electrode body and the nonaqueous electrolyte, wherein the battery case includes a current interrupt device that operates in response to an increase in an internal pressure of the battery case, the nonaqueous electrolyte contains a fluorine-containing compound and a gas producing agent, and the separator includes a hydrofluoric acid trapping layer containing an inorganic phosphate compound on a surface of the separator.

2 . The nonaqueous electrolyte secondary battery according to claim 1 , wherein
the separator includes the hydrofluoric acid trapping layer on a surface on a side opposite the positive electrode.

3 . The nonaqueous electrolyte secondary battery according to claim 1 , wherein
in the separator, a porous heat resistance layer is laminated on a surface of a separator substrate, and the hydrofluoric acid trapping layer is laminated on a surface of the porous heat resistance layer.

4 . The nonaqueous electrolyte secondary battery according to claim 1 , wherein
a ratio of a mass of the inorganic phosphate compound to total mass of the hydrofluoric acid trapping layer is 70 mass % to 99 mass %.

5 . The nonaqueous electrolyte secondary battery according to claim 1 , wherein
a ratio of a mass of a binder to total mass of the hydrofluoric acid trapping layer is 1 mass % to 20 mass %.

6 . The nonaqueous electrolyte secondary battery according to claim 1 , wherein
the positive electrode contains a positive electrode active material, and a content of the inorganic phosphate compound is 1 part by mass or more with respect to 100 parts by mass of a mass of the positive electrode active material.

7 . The nonaqueous electrolyte secondary battery according to claim 6 , wherein
the content of the inorganic phosphate compound is 5 parts by mass or less with respect to 100 parts by mass of the mass of the positive electrode active material.

8 . The nonaqueous electrolyte secondary battery according to claim 1 , wherein
the inorganic phosphate compound contains Li 3 PO 4 .

9 . The nonaqueous electrolyte secondary battery according to claim 1 , wherein
an average particle size of the inorganic phosphate compound is 10 μm or less.

Assignees

• Toyota Motor Co Ltd

Inventors

• Ito Yuichi

Classifications

• H01M10/052

  Li-accumulators · CPC title

• H01M2200/20

  Pressure-sensitive devices · CPC title

• H01M2300/0034

  Fluorinated solvents · CPC title

• H01M2300/0025

  Organic electrolyte · CPC title

• H01M10/4235 Primary

  Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence) · CPC title