Composite electrolyte membrane, catalyst-coated membrane assembly, membrane-electrode assembly and polymer electrolyte fuel cell

A composite electrolyte membrane comprising:

• a reinforcement layer made of a resin and having apertures therein;
• and an electrolyte layer made of a polymer electrolyte and laminated at least one main surface of the reinforcement layer,
• wherein, an axis X1 and an axis Y1 form an orthogonal coordinate system,
• wherein the orthogonal coordinate system is fixed on a main surface of the reinforcement layer,
• the reinforcement layer has strength anisotropy in which the tensile modulus of elasticity in the direction of the X1 axis is greater than the tensile modulus of elasticity in the direction of the Y1 axis,
• wherein, an axis X2 and an axis Y2 form an orthogonal coordinate system,
• wherein, the orthogonal coordinate system is fixed on a main surface of the electrolyte layer, the electrolyte layer has size anisotropy in which the rate of size change in the direction of the X2 axis is greater than the rate of size change in the direction of the Y2 axis, and
• the reinforcement layer and the electrolyte layer are laminated such that the direction of the X1 axis substantially corresponds with the direction of the X2 axis wherein the orthogonal coordinate systems are perpendicular to the electrolyte membrane and the reinforcement layer laminate direction.