GAS DIFFUSION LAYER FOR FUEL CELL

摘要

Disclosed is a gas diffusion layer (10) for use in a fuel cell, which comprises an electrically conductive microparticle layer (2) and a base layer (1).  The electrically conductive microparticle layer (2) has, formed therein, first void spaces (3) each having a diameter of 0.5 to 50 µm inclusive and second void spaces (4) each having a diameter of not smaller than 0.05 µm and smaller than 0.5 µm.  The base layer (1) also has void spaces (11) formed therein.  The total volume of the second void spaces (4) is not less than 50% and less than 100% relative to the total volume of the void spaces contained in the electrically conductive microparticle layer (2).  With respect to void spaces having a specific diameter (D1) and occupy the largest volume fraction among the first void spaces (3), the diameter (D1) is set so that a capillary force (F1) that acts on the first void spaces (3) is smaller than a capillary force (F2) that acts on the void spaces (11) contained in the base layer (1).  In this manner, the first void spaces (3) are directed to work as water passages and the second void spaces (4) are directed to work as gas passages.