Load changing performance is significant for the application of proton exchange membrane fuel cells (PEMFCs). This paper compares experimental results of the hydrogen-air and hydrogen-oxygen PEMFC and analyzes their dynamic performance under various operating conditions. We use electrochemical impedance spectroscopy to investigate the intrinsic mechanism during load changing. Due to the higher oxygen concentration, the hydrogen-oxygen PEMFC responds faster (within 1 second) and operates more steadily than the hydrogen-air PEMFC (2-20 seconds). The experimental results show that the total polarization resistance of the hydrogen-air PEMFC and the Ohmic resistance of the hydrogen-oxygen PEMFC decrease dramatically with the appropriately increased operating temperature. Whereas at over-elevated operating temperature, the resistance value increases due to the dehydration of the membrane electrode assembly. Load changing performance can be improved by increasing operating pressure and relative humidity. Increased stoichiometry is beneficial for the hydrogen-air PEMFC, while the opposite trend is observed for the hydrogen-oxygen PEMFC.

中文翻译：

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氢-空气和氢-氧质子交换膜燃料电池的负载变化特性

负载变化性能对于质子交换膜燃料电池 (PEMFC) 的应用具有重要意义。本文比较了氢-空气和氢-氧 PEMFC 的实验结果，并分析了它们在各种运行条件下的动态性能。我们使用电化学阻抗谱来研究负载变化过程中的内在机制。由于氧气浓度较高，氢氧 PEMFC 的响应速度更快（1 秒内），并且比氢空气 PEMFC（2-20 秒）运行更稳定。实验结果表明，氢-空气PEMFC的总极化电阻和氢-氧PEMFC的欧姆电阻随着工作温度的适当升高而显着降低。而在过高的工作温度下，由于膜电极组件的脱水，电阻值增加。负载变化性能可以通过增加工作压力和相对湿度来提高。增加的化学计量有利于氢-空气 PEMFC，而氢-氧 PEMFC 则观察到相反的趋势。