Mathematical modeling of a passive-feed DMFC with heat transfer effect

A passive liquid-feed direct methanol fuel cell (DMFC) with neither external liquid pumps nor gas blowers is modeled mathematically. A one-dimensional model is developed by considering inherently coupled heat and mass transport, along with the electrochemical reactions occurring in passive DMFCs. The analytical solutions predicting the performance of this type of fuel cell operating with different methanol concentrations are obtained. It is shown that the performance of passive DMFCs increases with methanol concentration. It is further revealed that the improved performance with higher methanol concentrations is due primarily to the increased operating temperature resulted from the exothermic reaction between permeated methanol and oxygen on the cathode.