Membrane electrode assembly and fuel cell comprising the same

Patent metadata

Field	Value
Publication number	US-2016197369-A1
Application number	US-201314410191-A
Country	US
Kind code	A1
Filing date	Jul 22, 2013
Priority date	Jul 25, 2012
Publication date	Jul 7, 2016
Grant date	—

Abstract

A membrane electrode assembly which includes an anode, a cathode and a solid polymer electrolyte membrane that are specifically arranged, wherein the cathode has a cathode catalyst layer and a cathode diffusion layer that is arranged on a surface of the cathode catalyst layer, the surface being on the side opposite the solid polymer electrolyte membrane side, the cathode catalyst layer contains an oxygen reduction catalyst composed of composite particles each of which is constituted of a catalyst metal containing palladium or a palladium alloy and a catalyst carrier containing, as constituent elements, a specific transition metal element M1, a transition metal element M2 other than the transition metal element M1, carbon, nitrogen and oxygen in a specific ratio, and the cathode diffusion layer contains an oxidation catalyst and a water-repellent resin.

First claim

1 . A membrane electrode assembly comprising an anode, a cathode and a solid polymer electrolyte membrane and having constitution in which the solid polymer electrolyte membrane is interposed between the anode and the cathode, wherein
the cathode has a cathode catalyst layer and a cathode diffusion layer that is arranged on a surface of the cathode catalyst layer, said surface being on the opposite side to the solid polymer electrolyte membrane side, the cathode catalyst layer contains an oxygen reduction catalyst composed of composite particles each of which is constituted of a catalyst metal and a catalyst carrier, the catalyst metal contains palladium or a palladium alloy, the catalyst carrier contains, as constituent elements, a transition metal element M1 that is at least one selected from the group consisting of titanium, zirconium, niobium and tantalum, a transition metal element M2 other than the transition metal element M1, carbon, nitrogen, and oxygen, the ratio of the number of atoms among the transition metal element M1, the transition metal element M2, carbon, nitrogen and oxygen (transition metal element M1:transition metal element M2:carbon:nitrogen:oxygen) is (1-a):a:x:y:z (with the proviso that a, x, y and z are numbers of 0<a≦0.5, 0<x≦7, 0<y≦2 and 0<z≦3), and the cathode diffusion layer contains an oxidation catalyst and a water-repellent resin.

2 . The membrane electrode assembly as claimed in claim 1 , wherein the transition metal element M2 is at least one selected from iron, nickel, chromium, cobalt, vanadium and manganese.

3 . The membrane electrode assembly as claimed in claim 1 , wherein the oxidation catalyst contained in the cathode diffusion layer is at least one selected from platinum, palladium, copper, silver, tungsten, molybdenum, iron, nickel, cobalt, manganese, zinc and vanadium.

4 . The membrane electrode assembly as claimed in claim 1 , wherein the water-repellent resin contained in the cathode diffusion layer is at least one selected from polytetrafluoroethylene, polychlorotrifluoroethylene, poly(vinylidene fluoride), poly(vinyl fluoride), a perfluoroalkoxyfluorine resin, a tetrafluoroethylene/hexafluoropropylene copolymer, an ethylene/tetrafluoroethylene copolymer, an ethylene/chlorotrifluoroethylene copolymer, polyethylene, polyolefin, polypropylene, polyaniline, polythiophene and polyester.

5 . The membrane electrode assembly as claimed in claim 1 , wherein the cathode catalyst layer further contains an electron conductive substance.

6 . A fuel cell comprising the membrane electrode assembly as claimed in claim 1 .

7 . The fuel cell as claimed in claim 6 , which further comprises a reaction intermediate removing filter for a direct liquid fuel cell, said reaction intermediate removing filter being for removing a reaction intermediate contained in a discharged matter from the electrode.

8 . The fuel cell as claimed in claim 7 , wherein the reaction intermediate removing filter for a direct liquid fuel cell comprises:
a gas-liquid separation member for selectively allowing a gas component in the discharged matter to permeate therethrough, and a catalyst part for allowing the gas component having permeated through the gas-liquid separation member to undergo oxidation combustion.

9 . The fuel cell as claimed in claim 6 , which is a direct methanol fuel cell.

Assignees

• Showa Denko Kk

Inventors

• Lee Kunchan
• Abe Yoshinori
• Ito Yuji

Classifications

• Y02E60/50

  Fuel cells · CPC title

• H01M8/1016

  characterised by the electrolyte material (H01M8/12 takes precedence) · CPC title

• H01M8/1011 Primary

  Direct alcohol fuel cells [DAFC], e.g. direct methanol fuel cells [DMFC] · CPC title

• H01M4/925

  supported on carriers, e.g. powder carriers · CPC title

• H01M8/1004 Primary

  characterised by membrane-electrode assemblies [MEA] (H01M8/12 takes precedence) · CPC title