Resin-framed membrane electrode assembly and fuel cell

Abstract

A solid polymer electrolyte membrane is made from a solid polymer electrolyte membrane roll in which a solid polymer electrolyte membrane sheet is wound in a winding direction. A first electrode is disposed on a first surface of the solid polymer electrolyte membrane in a stacking direction. A second electrode is disposed on a second surface of the solid polymer electrolyte membrane in the stacking direction and has a size smaller than a size of the first electrode viewed in the stacking direction. A resin frame member has a rectangular peripheral shape and a rectangular window therein viewed in the stacking direction. The rectangular stepped membrane electrode assembly is provided in the rectangular window so that the outer peripheral surface of the solid polymer electrolyte membrane is surrounded by the resin frame member. The rectangular peripheral shape has a longitudinal side which extends in the winding direction.

What is claimed is: 
     
         1 . A resin-framed membrane electrode assembly for a fuel cell, comprising:
 a rectangular stepped MEA including
 a solid polymer electrolyte membrane, 
 a first electrode that is disposed on one surface of the solid polymer electrolyte membrane and that includes a first electrode catalyst layer and a first gas diffusion layer, and 
 a second electrode that is disposed on the other surface of the solid polymer electrolyte membrane and that includes a second electrode catalyst layer and a second gas diffusion layer, 
 wherein planar dimensions of the first electrode are larger than those of the second electrode; and 
   a rectangular resin frame member that surrounds an outer periphery of the solid polymer electrolyte membrane,   wherein the resin frame member includes an inwardly-protruding portion that protrudes toward the second electrode,   wherein a clearance is formed between an outer edge of the second gas diffusion layer and an inner edge of the inwardly-protruding portion,   wherein the solid polymer electrolyte membrane is obtained by cutting a rolled solid polymer electrolyte membrane, and   wherein a winding direction in which the rolled solid polymer electrolyte membrane is wound coincides with a longitudinal direction of the resin frame member.   
     
     
         2 . The resin-framed membrane electrode assembly according to  claim 1 ,
 wherein the first electrode is an anode electrode to which a fuel gas is supplied,   wherein the second electrode is a cathode electrode to which an oxidant gas is supplied, and   wherein a supply pressure of the fuel gas supplied to the first electrode is higher than a supply pressure of the oxidant gas supplied to the second electrode.   
     
     
         3 . A fuel cell comprising:
 the resin-framed membrane electrode assembly according to  claim 1 ; and   a rectangular separator,   wherein the separator includes
 an oxidant gas inlet manifold that is located adjacent to one short side of the resin frame member and through which an oxidant gas flows in a stacking direction in which the resin-framed membrane electrode assembly and the separator are stacked, and 
 an oxidant gas outlet manifold that is located adjacent to the other short side of the resin frame member and through which the oxidant gas flows in the stacking direction. 
   
     
     
         4 . A resin-framed membrane electrode assembly for a fuel cell, comprising:
 a rectangular stepped membrane electrode assembly comprising:   a solid polymer electrolyte membrane made from a solid polymer electrolyte membrane roll in which a solid polymer electrolyte membrane sheet is wound in a winding direction, the solid polymer electrolyte membrane having a first surface, a second surface opposite to the first surface in a stacking direction, and an outer peripheral surface connecting the first surface and the second surface;   a first electrode disposed on the first surface of the solid polymer electrolyte membrane in the stacking direction; and   a second electrode which is disposed on the second surface of the solid polymer electrolyte membrane and which has a size smaller than a size of the first electrode viewed in the stacking direction, the second electrode comprising:
 a second electrode catalyst layer provided on the second surface of the solid polymer electrolyte membrane in the stacking direction; and 
 a second gas diffusion layer provided on the second electrode catalyst layer in the stacking direction; and 
   a resin frame member having a rectangular peripheral shape and a rectangular window therein viewed in the stacking direction, the rectangular stepped membrane electrode assembly being provided in the rectangular window so that the outer peripheral surface of the solid polymer electrolyte membrane is surrounded by the resin frame member, the resin frame member including an inwardly-protruding peripheral portion which protrudes toward an outer peripheral edge of the second electrode, the inwardly-protruding peripheral portion having an inner peripheral edge facing the outer peripheral edge of the second gas diffusion layer with a clearance therebetween, the rectangular peripheral shape having a longitudinal side which extends in the winding direction.   
     
     
         5 . The resin-framed membrane electrode assembly according to  claim 4 ,
 wherein the first electrode is an anode electrode to which a fuel gas is supplied,   wherein the second electrode is a cathode electrode to which an oxidant gas is supplied, and   wherein a supply pressure of the fuel gas supplied to the first electrode is higher than a supply pressure of the oxidant gas supplied to the second electrode.   
     
     
         6 . A fuel cell comprising:
 the resin-framed membrane electrode assembly according to  claim 4 ; and   a separator having a rectangular shape and stacked on the resin-framed membrane electrode assembly in the stacking direction,   wherein
 the rectangular peripheral shape has a lateral side which is perpendicular to the longitudinal side and which is shorter than the longitudinal side, 
 the separator includes
 an oxidant gas inlet manifold which is located adjacent to the lateral side of the resin frame member and through which an oxidant gas flows in the stacking direction, and 
 an oxidant gas outlet manifold which is located adjacent to the lateral side of the resin frame member and through which the oxidant gas flows in the stacking direction. 
 
   
     
     
         7 . The resin-framed membrane electrode assembly according to  claim 4 , wherein
 the first electrode catalyst layer is provided on the first surface of the solid polymer electrolyte membrane, and   the first gas diffusion layer is provided on the first electrode catalyst layer.