Unit cell of fuel cell

Patent metadata

Field	Value
Publication number	US-2017358806-A1
Application number	US-201715616078-A
Country	US
Kind code	A1
Filing date	Jun 7, 2017
Priority date	Jun 10, 2016
Publication date	Dec 14, 2017
Grant date	—

Abstract

A relation of X×ΔT×CTE t <L×t is satisfied, where X represents a distance between a circumferentially innermost position of a bonded portion of a resin frame bonded to first projections of separators and a circumferentially inner end of the resin frame; L represents a distance between the circumferentially inner end of the resin frame and a circumferentially outermost position of a held portion of a membrane electrode gas-diffusion-layer assembly that is interposed and held between second projections of the separators: ΔT represents a temperature difference from a low temperature T 1 of −40° C. to a high temperature T 2 of 100° C. CTE f represents an average coefficient of linear expansion of the resin frame within a range of the low temperature T 1 to the high temperature T 2; t represents a breaking elongation of the electrolyte membrane at the low temperature T 1; and the distances X, L represents dimensions at the high temperature T 2.

First claim

What is claimed is:

1 . A unit cell of a fuel cell, the unit cell comprising:
a membrane electrode gas-diffusion-layer assembly including a membrane electrode assembly having an electrolyte membrane and gas-diffusion layers provided on both faces of the membrane electrode assembly; a resin frame in a frame shape, the resin frame bonded to an outer circumferential region of the membrane electrode gas-diffusion layer assembly; and two separators holding therebetween the membrane electrode gas-diffusion-layer assembly to which the resin frame is bonded, the separators each having projections and recesses, wherein no gas-diffusion layers are formed on the membrane electrode assembly in the outer circumferential region of the membrane electrode gas-diffusion-layer assembly to which the resin frame is bonded, the resin frame is bonded onto the electrolyte membrane or onto an electrocatalyst layer formed on the electrolyte membrane, when, of the projections and the recesses of the two separators, portions in contact with the membrane electrode gas-diffusion-layer assembly to which the resin frame is bonded are defined to be projections, and portions apart from the membrane electrode gar diffusion-layer assembly are defined to be recesses, the separators include first projections and second projections as the projections, the outer circumferential region of the membrane electrode gas-diffusion-layer assembly to which the resin frame is bonded is disposed in spaces formed by the recesses of the two separators that face each other, the resin frame is interposed and held between, and is bonded to the first projections of the two separators that face each other, the first projections located more circumferentially outward than the recesses, the membrane electrode gas-diffusion-layer assembly is interposed and held between the second projections of the two separators that face each other, the second projections located more circumferentially inward than the recesses, in a cross section of the unit cell that is cut. at any position in a side of an outer shape of the membrane electrode gas-diffusion-layer assembly in section verbal to a direction of the side thereof, a relation of X×ΔT×CTE t <L×t is satisfied, where X represents a distance between a circumferentially innermost position of a bonded portion of the resin frame that is bonded to the first projections and a circumferentially inner end of the resin frame, L represents a distance between the circumferentially inner end of the resin frame and a circumferentially outermost position of a held portion of the membrane electrode gas-diffusion-layer assembly that is interposed and held between the second projections, ΔT represents a temperature difference from a low temperature T 1 of −40° C. to a high temperature T 2 of 100° C., CTE f represents an average coefficient of linear expansion of the resin frame within a range of the low temperature T 1 to the high temperature T 2 , t represents a breaking elongation of the electrolyte membrane at the low temperature T 1 , and the distances X, L represent dimensions at the high temperature T 2 .

2 . The unit cell according to claim 1 , wherein
a relation of X×ΔT×CTE t <(1−ΔT×CTE m )L×t is satisfied, where CTE m represents an average coefficient of linear expansion of the electrolyte membrane within the range of the low temperature T 1 to the high temperature T 2 .

Assignees

• Toyota Motor Co Ltd

Inventors

• Shizuku Fumishige
• Okada Sachio
• Kajiwara Takashi

Classifications

• H01M8/1004 Primary

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

• H01M8/0284

  Organic resins; Organic polymers · CPC title

• H01M8/0297

  Arrangements for joining electrodes, reservoir layers, heat exchange units or bipolar separators to each other (H01M8/0271 takes precedence) · CPC title

• H01M8/0254

  corrugated or undulated · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title