Examination of the influence of PTFE coating on the properties of carbon paper in polymer electrolyte fuel cells

Polymer electrolyte fuel cells gain momentum due to the attainable high power densities and their relatively simple handling. Because their actual reactive catalytic layer is about < 10 mu m, carbon papers are frequently used as additional backing in order to improve the gas distribution and water management in the fuel cell. To avoid flooding of the electrodes by the product water, the carbon paper is usually hydrophobed by partial coating with PTFE suspension. The influence of the PTFE coating and the following sintering time on through paper plane conductivity, gas permeability and paper hydrophobicity is analysed and discussed.