The effect of capillary forces in a porous electrode on output current voltage characteristics of fuel cell with polymer proton exchange membrane

A mathematical isothermal model of a polymer proton exchange membrane fuel cell (PEMFC) cathode accounting for the capillary forces is derived and discussed. On the basis of analytical and numerical calculations, it is shown that capillary forces have a principal effect on the operating voltage drop due to a thin water film arising in wet-proofed pores under certain conditions and thus presenting the burden barrier for oxygen diffusion as compared with ordinary oxygen diffusion in a gas mixture. The calculations made are in good accordance with known experimental data.