Experimental investigation on voltage response characteristics of hydrogen-oxygen proton exchange membrane fuel cells under gas starvation

Hydrogen and oxygen starvation during operation have an irreversible impact on performance of proton exchange membrane fuel cell (PEMFC), which seriously restricts its working life. In this study, the voltage response characteristics of hydrogen-oxygen PEMFC under different degrees of hydrogen and oxygen starvation were experimentally studied, and the gas starvation tolerance was further analyzed through polynomial fitting. The results show that the response of voltage changes from stable to gradual decay with time under a certain degree of gas starvation. In the case of hydrogen starvation, the response voltage decreases in a parabolic trend, which indicates that PEMFC have poor tolerance to hydrogen starvation. While the response voltage basically shows a linear downward trend in oxygen starvation condition, and it lags behind the change of oxygen concentration. In addition, compared with oxygen starvation, hydrogen starvation causes more serious damage. It was found that after hydrogen starvation experiment, the performance was deceased by 39.36%, the electrochemical active surface area decreased by 18.37%, and the charge transduction resistance increased by 47.24%. It is also found that increasing the working temperature effectively alleviate this degradation phenomenon, which is expected to be an effective mitigation strategy for the damage by gas starvation.