Investigation of Performance Degradation and Control Strategies of PEMFC under Three Typical Operating Conditions

Abstract

Accelerated durability test methods exist for proton exchange membrane fuel cells. However, there is no standardized method for estimating their lifetime. Moreover, the coupling degradation mechanism under typical automotive conditions remains obscure, severely hindering durability improvement. The present study investigated the degradation behavior and the mechanism and control strategies under three typical operating conditions. The dynamic load rate should not exceed 150 mA cm−2 s−1 to ensure proper response times and voltage decay rates. The continuous runtime should not exceed 5 h to cater for longer operations with a slow rate of voltage decay. For the purge strategy during the shutdown condition, the auxiliary load purge condition had a lower voltage decay rate, which can significantly reduce the unnecessary attenuation during the shutdown. After characterization with electrochemical test methods, the degradation mechanism under three typical operating conditions was mainly manifested by the attenuation of catalytic activity and the impairment of mass transfer capacity. Furthermore, this study further clarified the quantitative relationship between degradation mechanism and performance decline, guiding the optimization of actual on-board control strategies for proton exchange membrane fuel cells.