Effect of Reverse Voltage on Proton Exchange Membrane Fuel Cell Performance

Reverse voltage could be occurred on proton exchange membrane fuel cell (PEMFC) by fuel starvation and/or uneven gas distribution in flow channel. The performance of PEMFC was decreased by reverse voltage. Performance decrease in local area could be affected by duration and/or extent of reverse voltage. Hydrogen stoichiometric ratio was used to find the experimental condition of abrupt voltage decrease. In case that specific cell was reached to reverse voltage, the cell performance was checked every 5 cycle. LabVIEW was used to make control logic of automatic load off system in preset voltage. Performance change experiment was carried out at constant current condition. When the cell voltage was reached to 0.1 V, electronic load was disconnected to make open circuit voltage for 1 minute. Fuel cell performance was checked every 5 cycle and the degree of performance decrease and/or recovery was estimated. Cell performance was maintained up to 40 cycle in case that the load off condition was set at 0 V.