Laminated body, separator, and nonaqueous secondary battery

Patent metadata

Field	Value
Publication number	US-9865857-B2
Application number	US-201514781791-A
Country	US
Kind code	B2
Filing date	Jul 27, 2015
Priority date	Aug 29, 2014
Publication date	Jan 9, 2018
Grant date	Jan 9, 2018

Abstract

A first laminated body includes: a porous film containing a polyolefin as a main component; and a porous layer on at least one surface of the porous film, the porous layer containing a resin. A second laminated body includes: a porous film containing a polyolefin as a main component; and a porous layer containing a resin. The laminated body is usable as a secondary battery separator having a higher dielectric strength. A third laminated body is provided in which occurrence of a curl is prevented. A nonaqueous secondary battery separator is provided disposed between a cathode and an anode, the separator including: a porous base material containing a polyolefin as a main component; and a porous layer on at least one surface of the porous base material, the porous layer containing a polyvinylidene fluoride-based resin.

First claim

The invention claimed is:

1. A separator, comprising:
a laminated body comprising:
a stack of (i) a first porous layer containing a polyolefin-based resin and (ii) a second porous layer containing a polyvinylidene fluoride-based resin,
a difference between (A) a water content rate of the laminated body in an atmosphere having a dew point of 20° C. and (B) a water content rate of the laminated body in an atmosphere having a dew point of −30° C. is 100 ppm or more and 1000 ppm or less,
a difference between (C) a water content of the first porous layer and (D) a water content of the second porous layer both in an atmosphere having a dew point of 20° C. is 1 mg/m 2 or more and 10 mg/m 2 or less, and
respective openings of pores each having an area of 0.5 μm 2 or more occupying 0.001% to 30% of a surface of the second porous layer.

2. The separator according to claim 1 ,
wherein
the respective openings occupy 5% or less of the surface of the second porous layer.

3. The separator according to claim 1 ,
wherein
the second porous layer either (i) has a structure in which skeletons each having a diameter of 1 μm or less are connected to each other to form a three-dimensional network or (ii) contains a fine resin particle.

4. The separator according to claim 3 ,
wherein
the fine resin particle is of a resin having a structure unit derived from α-olefin having 2 to 4 carbon atoms.

5. A nonaqueous secondary battery, comprising the separator according to claim 1 .

Assignees

• Sumitomo Chemical Co

Inventors

• Murakami Chikara
• Ogata Toshihiko
• Arise Ichiro
• Kurakane Kosuke
• Yoshimaru Chikae

Classifications

• H01M4/505 Primary

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M50/417

  Polyolefins · CPC title

• H01M50/426 Primary

  Fluorocarbon polymers · CPC title

• H01M50/491

  Porosity · CPC title

• H01M50/449

  having a layered structure · CPC title