质子交换膜燃料电池电流分布研究

Study on current distribution of PEMFC

燃料电池电流分布直接反映电极表面的电化学过程,研究电流密度分布有助于分析电极过程的特征,有利于提高催化剂的利用率。采用电极催化区域分区的方法研究了气体流道区域与集流体区域电流分布的不同。分析了气体流道区域与集流体区域的电阻分布,考察了气体加湿及氧气供给对上述两区域电化学过程的影响。结果表明,小电流密度区间,气体无论是加湿还是干燥条件,电阻的影响要强于气体供给的影响,即集流体区域电流密度高于气体流道区域;而大的电流密度区间,电流在集流体区域与气体流道区域的分布决定于反应点的电阻及气体供给两种因素。

Current distribution in proton exchange membrane fuel cell reflects the electrochemical reaction characteristic directly. Segment catalyst layer method was used to measure the current distribution between the flow channel region and the current collector region. The resistant difference of the two regions was analyzed, and the effects of humidification and reactant supply on the electrochemical reaction process were investigated. The results indicate that the current collector region provides higher current density than that of flow channel region at low current density, whatever humidification was used or not. However, the current distributions between the two regions are determined by the tradeoff of the resistance and the reactant supply at high current density.