Characterization of the DMFC Stack With a BOP System

A direct methanol fuel cell (DMFC) with a BOP system is introduced. The DMFC stack operating with this BOP system is characterized. The DMFC stack performance gradually degrades as flooding occurs. A series of experiments under different environmental conditions were carried out to determine the ways for minimizing flooding. The results show that the water flooding more easily occurs when the DMFC stack operating in a closed system than in an open system. In a closed system, the temperature is the most important control factor to maintain the DMFC stack sustainable operation. Lower temperature differences among the airflow entrance, the exterior side DMFC module, and the DMFC sidewall temperature could reduce the possibility of water flooding occurs inside the DMFC stack. In addition, a large temperature difference between airflow entrance and exit of the DMFC stack would also lead the water flooding inside the stack.