Polymer electrolyte membrane

Patent metadata

Field	Value
Publication number	US-2017012313-A1
Application number	US-201415100010-A
Country	US
Kind code	A1
Filing date	Dec 1, 2014
Priority date	Nov 29, 2013
Publication date	Jan 12, 2017
Grant date	—

Abstract

The present invention provides a polymer electrolyte membrane having excellent strength, a small dimensional change, and a low membrane resistance. The polymer electrolyte membrane includes a porous film and a polymer electrolyte. The porous film has a fibril/node area ratio of 90/10 to 75/25.

First claim

1 . A polymer electrolyte membrane comprising:
a porous film; and a polymer electrolyte, the porous film having a fibril/node area ratio of 90/10 to 75/25.

2 . The polymer electrolyte membrane according to claim 1 ,
wherein the porous film has a contact angle with a solution of the polymer electrolyte of 50 degrees or smaller.

3 . The polymer electrolyte membrane according to claim 1 ,
wherein the polymer electrolyte is a fluoropolymer electrolyte.

4 . The polymer electrolyte membrane according to claim 3 ,
wherein the fluoropolymer electrolyte is a copolymer comprising a repeating unit derived from a COOZ or SO 3 Z group-containing monomer represented by the following formula (I):
CF 2 ═CF(CF 2 ) k —O l —(CF 2 CFY 1 —O) n —(CFY 2 ) m -A 1   (I)

wherein Y 1 is F, Cl, or a perfluoroalkyl group; k is an integer of 0 to 2; l is 0 or 1; n is an integer of 0 to 8, n Y 1 s may be the same as or different from each other; Y 2 is F or Cl; m is an integer of 0 to 12, if m=0, l=0 and n=0, m Y 2 s may be the same as or different from each other; A 1 is COOZ or SO 3 Z, where Z is an alkali metal, an alkaline earth metal, hydrogen, or NR 1 R 2 R 3 R 4 , where R 1 , R 2 , R 3 , and R 4 are each individually a C1-C3 alkyl group or hydrogen, and
a repeating unit derived from tetrafluoroethylene.

5 . The polymer electrolyte membrane according to claim 1 ,
wherein the porous film has a product of vertical and lateral matrix tensile strengths of 2.20×10 4 MPa 2 or greater.

6 . The polymer electrolyte membrane according to claim 1 ,
wherein the polymer electrolyte is filled into pores of the porous film, and the porous film is a polytetrafluoroethylene porous film prepared by stretching semi-sintered polytetrafluoroethylene and heat-setting the stretched semi-sintered polytetrafluoroethylene at a temperature of not lower than the melting point of sintered polytetrafluoroethylene.

7 . The polymer electrolyte membrane according to claim 1 ,
wherein the porous film has an average pore size of 0.05 μm or greater.

8 . The polymer electrolyte membrane according to claim 1 ,
wherein the porous film has a film density of 1.4 g/cm 3 or lower.

9 . The polymer electrolyte membrane according to claim 1 ,
wherein the porous film has a thickness of smaller than 20 μm.

10 . The polymer electrolyte membrane according to claim 1 ,
wherein the porous film is a polytetrafluoroethylene porous film and the polytetrafluoroethylene has a standard specific gravity of 2.160 or lower.

11 . A membrane electrode assembly comprising the polymer electrolyte membrane according to claim 1 .

12 . A polymer electrolyte fuel cell comprising the membrane electrode assembly according to claim 11 .

Assignees

• Asahi Kasei E Materials Corp
• Daikin Ind Ltd

Inventors

• Inoue Yuichi
• Miyazaki Kuon
• Tanaka Norihito
• Kikuchi Kentaro
• Uraoka Nobuki
• Chaen Shinichi
• Konishi Tomohisa
• Ino Tadashi

Classifications

• H01M8/1067 Primary

  characterised by their physical properties, e.g. porosity, ionic conductivity or thickness · CPC title

• C08J2427/18

  Homopolymers or copolymers of tetrafluoroethylene · CPC title

• H01M8/106

  characterised by the chemical composition of the porous support · CPC title

• H01M2300/0082

  Organic polymers · CPC title

• H01M8/1027

  having carbon, oxygen and other atoms, e.g. sulfonated polyethersulfones [S-PES] · CPC title