Liquid composition, process for its production, and process for producing membrane-electrode assembly for polymer electrolyte fuel cells

Patent metadata

Field	Value
Publication number	US-10916790-B2
Application number	US-201816173902-A
Country	US
Kind code	B2
Filing date	Oct 29, 2018
Priority date	Jun 22, 2004
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

An electrolyte membrane is prepared from a liquid composition comprising at least one member selected from the group consisting of trivalent cerium, tetravalent cerium, bivalent manganese and trivalent manganese; and a polymer with a cation-exchange group. The liquid composition is preferably one containing water, a carbonate of cerium or manganese, and a polymer with a cation-exchange group, and a cast film thereof is used as an electrolyte membrane to prepare a membrane-electrode assembly. The present invention successfully provides a membrane-electrode assembly for polymer electrolyte fuel cells being capable of generating the electric power in high energy efficiency, having high power generation performance regardless of the dew point of the feed gas, and being capable of stably generating the electric power over a long period of time.

First claim

What is claimed is:

1. A liquid composition comprising at least one member selected from the group consisting of trivalent cerium and tetravalent cerium; and a polymer having a cation-exchange functional group wherein the polymer is a perfluorocarbon polymer having a sulfonic acid group.

2. The liquid composition according to claim 1 , which further comprises water.

3. The liquid composition according to claim 2 , wherein at least one member selected from the group consisting of trivalent cerium, tetravalent cerium is present in an ionic state.

4. The liquid composition according to claim 1 , wherein the polymer is dispersed.

5. The liquid composition according to claim 1 , wherein the trivalent or tetravalent cerium is contained in an amount of from 0.3 to 30 mol % relative to a molarity of —SO 3 − in the polymer.

6. The liquid composition according to claim 1 , wherein an ion exchange capacity of the polymer is from 0.5 to 3.0 milliequivalent/g dry resin.

7. The liquid composition according to claim 1 , wherein the polymer is a copolymer containing repeating units based on tetrafluoroethylene and repeating units based on a perfluorovinyl compound represented by CF 2 =CF—(OCF 2 CFX)m-Op—(CF 2 )n-SO 3 H where X represents a fluorine atom or a trifluoromethyl group, m represents an integer of from 0 to 3, n represents an integer of from 1 to 12 and p represents 0 or 1.

8. The liquid composition according to claim 7 , which further comprises water.

9. The liquid composition according to claim 8 , wherein at least one member selected from the group consisting of trivalent cerium, tetravalent cerium is present in an ionic state.

10. The liquid composition according to claim 8 , wherein the polymer is dispersed.

11. The liquid composition according to claim 8 , wherein the trivalent or tetravalent cerium is contained in an amount of from 0.3 to 30 mol % relative to a molarity of —SO 3 − in the polymer.

12. The liquid composition according to claim 8 , wherein an ion exchange capacity of the polymer is from 0.5 to 3.0 milliequivalent/g dry resin.

Assignees

• Agc Inc

Inventors

• Kawazoe Hisao
• Endoh Eiji
• Nakagawa Hideki
• Terazono Shinji

Classifications

• B01D67/00113

  Pretreatment of the casting solutions, e.g. thermal treatment or ageing · CPC title

• B01D69/1411

  containing dispersed material in a continuous matrix · CPC title

• Y02E60/50

  Fuel cells · CPC title

• C08J2327/18

  Homopolymers or copolymers of tetrafluoroethylene · CPC title

• H01M4/9016

  Oxides, hydroxides or oxygenated metallic salts · CPC title