Polymer electrolyte membrane

• US 10,644,339 B2
• Filed: 12/01/2014
• Issued: 05/05/2020
• Est. Priority Date: 11/29/2013
• Status: Active Grant

• Current Assignee: Asahi Kasei Kabushiki Kaisha, Daikin Industries Ltd
• Original Assignee: Asahi Kasei Kabushiki Kaisha
• Inventors: Inoue, Yuichi, Miyazaki, Kuon, Tanaka, Norihito, Kikuchi, Kentaro, Uraoka, Nobuki, Chaen, Shinichi, Konishi, Tomohisa, Ino, Tadashi
• Primary Examiner(s): Lee, Sin J
• Application Number:
  US15/100,010
• Publication Number:
  US 20170012313A1
• Time in Patent Office: 1,982 Days
• Field of Search: None
• CPC Class Codes: C08F 214/262 with fluorinated vinyl ethers
• CPC Class Codes: C08F 216/14 Monomers containing only one unsaturated aliphatic radical
• CPC Class Codes: C08F 216/1483 Monomers containing sulfur and nitrogen
• CPC Class Codes: C08J 2327/18 Homopolymers or copolymers of tetrafluoroethylene
• CPC Class Codes: C08J 2427/12 containing fluorine atoms
• CPC Class Codes: C08J 2427/18 Homopolymers or copolymers of tetrafluoroethylene
• CPC Class Codes: C08J 5/2237 containing fluorine
• CPC Class Codes: H01B 1/122 Ionic conductors
• CPC Class Codes: H01M 2008/1095 Fuel cells with polymeric electrolytes
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 8/1004 characterised by membrane-electrode assemblies [MEA] H01M8/12 takes precedence
• CPC Class Codes: H01M 8/1023 having only carbon, e.g. polyarylenes, polystyrenes or polybutadiene-styrenes
• CPC Class Codes: H01M 8/1027 having carbon, oxygen and other atoms, e.g. sulfonated polyethersulfones [S-PES]
• CPC Class Codes: H01M 8/1039 halogenated, e.g. sulfonated polyvinylidene fluorides
• CPC Class Codes: H01M 8/106 characterised by the chemical composition of the porous support
• CPC Class Codes: H01M 8/1062 characterised by the physical properties of the porous support, e.g. its porosity or thickness
• CPC Class Codes: H01M 8/1067 characterised by their physical properties, e.g. porosity, ionic conductivity or thickness
• CPC Class Codes: Y02E 60/50 Fuel cells

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.

Claims

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 and a contact angle with a solution of the polymer electrolyte of 44 degrees or smaller,

wherein the porous film having a film density of 0.80 g/cm³ or lower,

wherein the polymer electrolyte is a fluoropolymer electrolyte, wherein the fluoropolymer electrolyte is a copolymer comprising

a repeating unit derived from a COOZ or SO₃Z group-containing monomer represented by the following formula (I);

CF₂=CF(CF₂)_k—

O₁—

(CFY²)_m-A¹ 

 

(I)

wherein k is an integer of 0 to 2;

1 is 0 or 1;

m is an integer of 0 to 12, if m=0, then 1=0, when m is an integer of 1 to 12, Y² is F or Cl and m Y²s may be the same as or different from each other;

A¹ is COOZ or SO₃Z, where Z is an alkali metal, an alkaline earth metal, hydrogen, or NR¹R²R³R⁴, where R¹, R², R³, and R⁴ are each individually a C1-C3 alkyl group or hydrogen, and

a repeating unit derived from tetrafluoroethylene.

2. 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×

10⁴ MPa² or greater.

3. 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.

4. The polymer electrolyte membrane according to claim 1,

wherein the porous film has an average pore size of 0.05 μ

m or greater.

5. The polymer electrolyte membrane according to claim 1,

wherein the porous film has a thickness of smaller than 20 μ

m.

6. 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.

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

8. A polymer electrolyte fuel cell comprising the membrane electrode assembly according to claim 7.