Resin-framed membrane-electrode assembly for fuel cell

Abstract

A resin-framed membrane-electrode assembly for a fuel cell includes a stepped membrane-electrode assembly and a resin frame member. The stepped membrane-electrode assembly includes a polymer electrolyte membrane, a first electrode, and a second electrode. The resin frame member surrounds an outer perimeter of the polymer electrolyte membrane and includes an inner perimeter base end and an inner protruding portion. The inner protruding portion includes a flat surface portion which extends to face an outer perimeter surface portion of a second surface of the polymer electrolyte membrane and on which an adhesive layer is provided so that the adhesive layer lies at least between the flat surface portion and the outer perimeter surface portion. The adhesive layer has a tapered shape in which a thickness of the adhesive layer increases from a tip of the inner protruding portion toward the inner perimeter base end.

Description

technical field [0001] The present invention relates to an electrolyte membrane-electrode structure with a resin frame for a fuel cell, which includes a so-called stepped MEA in which a solid polymer electrolyte membrane is sandwiched between a first electrode and a second electrode, and is provided around the outer periphery of the stepped MEA. resin frame member. Background technique [0002] In general, a solid polymer fuel cell employs a solid polymer electrolyte membrane composed of a polymer ion exchange membrane. The fuel cell includes an electrolyte membrane-electrode structure (MEA) in which an anode electrode is disposed on one side of a solid polymer electrolyte membrane, and a cathode electrode is disposed on the other side of the solid polymer electrolyte membrane. The anode electrode and the cathode electrode each have a catalyst layer (electrode catalyst layer) and a gas diffusion layer (porous carbon). [0003] A fuel cell is constituted by sandwiching an e...

AI Technical Summary

Problems solved by technology

[0012] However, in the bonding process between the stepped MEA 4 and the packing sheet structure 5, when the adhesive is excessively applied to the bonding portion 6 or the bonding load is uneven, the adhesive may flow from the bonding portion 6 6 exposed

[0013] In addition, as for the bonding part 6, a closed space is often formed, and when the adhesive is spread in the bonding part 6, air may not be able to escape from the bonding part 6.

As a result, the adhesive cannot be applied to a uniform thickness due to air remaining in the bonding portion 6, resulting in large variations in quality such as gas barrier properties and bonding durability.

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