运行参数对质子交换膜燃料电池堆耐久性影响的实验研究

To address the issuc of limited durability of limited durability of proton exchange membrane fuel cells (PEMFC) under variable operating conditions, the gas distribution, voltage recovery, and voltage decay rate patterns during the aging process of hydrogen fuel cell Stacks, as well as the relationship between variations in membrane electrode assembly (MEA) Parameters among individual cells and cell aging was investigated. A durability testing procedure based on the new European driving cycle Standard working conditions was established and an accelerated aging test for 80 hours was condueted on a self-designcd 8-ccll PEMFC Stack. The results show that the average baseline voltage decay rate of the Stack is 1. 4 mV/h, decreasing to 0. 55 mV/h considering the voltage increase caused by the recovery of water-thermal State duc to restart. The change in the electrochemical reaction arca of various membrane electrode assemblies beforc and aftcr aging ranged betwecn 7% and 12% > but significant differences were observed in other MEA indicators, indicating largc variations in the water-thermal State. In terms of air distribution characteristics, the air flow rate distribution and voltage decay rate on the air sidc of individual cells exhibited a bimodal pattern. As the flow rate increases, the diffcrcncc in peak values becomes morc pronounced. The highest voltage decay rates corresponded to the highest flow rates, suggesting a positive correlation between aging rate and air flow. The cells near the end plates showed higher aging levels than the average, but their voltage decay rates were not the highest, indicating primarily reversible aging, which was further confirmed by higher voltage recovery rates. The aging rates of the middle cells were around 0. 6 mV/h.