Cold start characteristics and freezing mechanism dependence on start-up temperature in a polymer electrolyte membrane fuel cell
Cold start characteristics and freezing mechanism dependence on start-up temperature in a polymer electrolyte membrane fuel cell
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DOI：
10.1016/j.jpowsour.2012.02.052
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发表时间：
2012-06
影响因子：
9.2
通讯作者：
Yutaka Tabe;Masataka Saito;K. Fukui;T. Chikahisa
中科院分区：
文献类型：
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作者：
Yutaka Tabe;Masataka Saito;K. Fukui;T. Chikahisa
对聚合物电解质膜燃料电池的冷启动特性进行了实验研究，并对电池内部的冻结机理进行了微观观察。结果表明，冻结机制可以分为两种类型：阴极催化剂层在非常低的温度（如-20 °C）下冻结，以及催化剂层和气体扩散层之间的界面处的过冷水在0°C（如-10 °C）附近冻结。在冷启动过程中产生的水量与聚合物电解质膜的初始湿度条件有关，因为由于反向扩散引起的膜的吸水对于防止水冻结起重要作用。还表明，在冷启动关闭后，在-10 ° C下冻结后，随后在30°C下运行的电池性能暂时恶化，但在-20 °C下冻结后不会恶化。估计在催化剂层和气体扩散层之间的界面处形成的冰导致暂时劣化，并且还讨论了覆盖气体扩散层的微孔层对于冰形成的作用。
Cold start characteristics of a polymer electrolyte membrane fuel cell are investigated experimentally, and microscopic observations are conducted to clarify the freezing mechanism in the cell. The results show that the freezing mechanism can be classified into two types: freezing in the cathode catalyst layer at very low temperature like −20°C, and freezing due to supercooled water at the interface between the catalyst layer and the gas diffusion layer near 0°C like −10°C. The amount of water produced during the cold start is related to the initial wetness condition of the polymer electrolyte membrane, because water absorption by the membrane due to back diffusion plays an important role to prevent the water from freezing. It is also shown that after the shutdown of the cold start the cell performance of a subsequent operation at 30°C is temporarily deteriorated after the freezing at −10°C, but not after the freezing at −20°C. The ice formed at the interface between the catalyst layer and the gas diffusion layer is estimated to cause the temporary deterioration, and the function of a micro porous layer coating the gas diffusion layer for the ice formation is also discussed.