Effect of cathode moisture condensation on temperature distribution characteristics of dead‐ended proton‐exchange membrane fuel cell stack

Abstract

Thermal and water management are crucial factors affecting the performance of proton-exchange membrane fuel cells (PEMFCs). In this study, a semiconductor cooler was installed at the cathode outlet of a dead-ended fuel cell stack, to condense the water vapor in the stack, and subsequently realize efficient thermal and water management. The temperature distribution characteristics were experimentally studied using a self-built dead-ended PEMFC stack test platform. The effects of operating temperature, current density, and condensation temperature were analysed in detail. The results showed that the output performance of the dead-ended fuel cell stack could be efficiently improved by cathode moisture condensation. The temperature difference in the stack with cathode moisture condensation was much smaller than that without it. The output voltage of the stack could be increased by up to 6.02% with cathode moisture condensation, at an operating temperature of 70°C; and the maximum temperature difference could be reduced by 92.8% upon applying the semiconductor cooler with a condensation temperature of 5°C. Furthermore, the current density significantly affected the temperature distribution. Upon increasing the current density from 0.3 to 0.7 A/cm2, the temperature difference increased from 1.37°C to approximately 3°C, due to the large amount of water generated by electrochemical reaction at high current density.