FUEL CELL GAS DIFFUSION LAYER BASE MATERIAL AND METHOD FOR PRODUCING SAME

A method for producing a fuel cell gas diffusion layer base material sequentially Includes: a water-containing sheet preparation step (S1) of preparing a water-containing sheet (11) containing a carbon fiber (C1), graphite particles (P1) having a particle diameter more than 120 µm as measured by a laser diffraction/scattering method, and a fibrillated organic fiber (R1), which is to be carbonized in a subsequent carbonization step (S5), by using a slurry containing the carbon fiber, the graphite particles, and the fibrillated organic fiber; a composite sheet preparation step (S2) of preparing a composite sheet (12) by water-squeezing and drying the water-containing sheet; a resin impregnation step (S3) of preparing a resin impregnation sheet (13) by impregnating the composite sheet with a carbon precursor resin to be carbonized in the subsequent carbonization step; a compression step (S4) of preparing a thinned sheet (14) by compressing the resin impregnation sheet; and the carbonization step of heating and firing the thinned sheet in a non-oxidizing atmosphere.