Gas diffusion layer for polymer electrolyte fuel cell having conductive porous layer formed thereon, paste composition for forming conductive porous layer, production method thereof, and polymer electrolyte fuel cell

摘要

PROBLEM TO BE SOLVED: To provide a paste composition for forming a conductive porous layer, for stably forming a conductive porous layer that can impart further superior gas permeability and diffusing property, and to provide a polymer electrolyte fuel cell using a gas diffusion layer which includes the conductive porous layer formed on a conductive porous substrate.SOLUTION: The gas diffusion layer for a polymer electrolyte fuel cell includes a conductive porous layer formed on a conductive porous substrate. The conductive porous layer is formed by forming, on the conductive porous substrate, a paste composition for forming a conductive porous layer, which contains at least conductive carbon particles, a water-repellent resin and a dispersant. In the conductive porous layer, the sum of volume of pores having a pore diameter of 25 to 1000 nm is 1.4 ml/g or more and an occupation area of cracks is 0.8% to 2.5%.