HYDROPHILIC POROUS LAYER FOR FUEL CELLS, GAS DIFFUSION ELECTRODE AND MANUFACTURING METHOD THEREOF, AND MEMBRANE ELECTRODE ASSEMBLY

摘要

[Summary] [Object] To provide a hydrophilic porous layer for a fuel cell that improves a sub-zero temperature starting ability of the fuel cell. [Solving means] A hydrophilic porous layer comprising electrically conductive material - hydrophilic material aggregates each including hydrophilic materials and electrically conductive materials that intimately contact to one another, the hydrophilic materials being mutually connected to one another to form in the hydrophilic materials a continuous transport path for water, the electrically conductive material - hydrophilic material aggregates forming therebetween a transport path for water vapor, which is characterized in that when it is above -40°C, a water transport resistance Rwater of the water transport path is larger than a water vapor transport resistance Rgas of the water vapor transport path.