Influence of Liquid Water Distribution on PEM Fuel Cell Performance Using Cathode-Anode Model: A 3D Numerical Study

Polymer electrolyte membrane (PEM) fuel cell directly converts the chemical energy of the fuel into electrical energy thus providing higher energy conversion efficiency. Liquid water causes flooding in the Gas Diffusion Layer, Catalyst Layer as well as in channels due to which the active catalyst surface area in the CL reduces and hence the reaction rate reduces. Phase transfer between liquid water and water vapour along with electro-osmotic drag and reverse diffusion through the membrane, are the factors influencing liquid water buildup in the domains. In the present work a three dimensional, non-isothermal, two phase numerical model incorporating cathode and anode domains for studying water distribution is developed. Water formation and distribution across the domain are studied using the mixed flow distributor. The developed numerical model is validated by comparing the polarization curve with the experimental results. The study shows that the ohmic region in the polarization curve increases and the concentration losses decrease due to the use of pure oxygen at inlet which can be important for applications such as in spacecrafts. The effects of liquid water accumulation in the domain on the reactant transport, current density and temperature distribution are also investigated.