Preparation and characterization of carbon black/pitch-based carbon fiber paper composites for gas diffusion layers

We prepared carbon Ketjenblack (KB)/carbon fiber papers (CFPs) from pitch-based carbon fibers (CFs) by web-laid processing, and the electrical conductivity and mechanical properties of the CFPs were investigated according to the structure and morphology of the CFs by the addition of KB as a conductive filler at different carbonization temperatures. The wet-laid processing fabrication method for CFPs consisted of four steps: dispersion of CFs, preparation of a CF web, impregnation of phenol resin, and heat treatment. The results showed that the electrical resistance and tensile strength of the CFPs were low at high-heat-treatment temperatures. Notably, CFPs with a thickness of 190 μm, porosities of 86.7%, and specific resistance of 7.795 × 10⁻² Ω cm were obtained by after adding 6 wt.% of KB at a carbonization temperature of 800 °C.