Performance of a Polymer Electrolyte Fuel Cell for Automotive Applications. 2nd Report. Characteristics of Self-Humidifying Operation of a 200W PEFC Stack.

The objective of this study was to fabricate a self-humidifying fuel cell stack humidified with water recovered at the cathodes, composed of 10 cells with 104 cm2 cell areas, measure and simulate the performance of the stack. The model for the simulation is a three-dimensional model of the heat and mass transfer of water and gaseous reactants in fuel cell components with water cooling. The results of the stack experiments showed a maximum power of 250 W at the current density of 0.5 A/ cm2. The simulation model showed good agreement with the actual performance of the stack. A self-humidifying stack with a vapor permeating membrane showed a performance comparable to conventional stacks and it is very effective in simplifying stack systems. The numerical analysis showed that the stack performance is affected by the anode and cathode gas flows, co-flow is superior to cross-flow and that one cooing cell is necessary for two or three generating cells to maintain a fuel cell temperature below 100°C.