不同蛇形流场下的直接甲醇燃料电池性能及阻抗分析

摘要

The performances and impedances of direct methanol fuel cells with single channel serpentine flow field and multichannel serpentine flow field are studied. The VA( volt-ampere) characteristics and AC(alternating-current) impedance of serpentine flow field methanol fuel cell are measured in this experiment, and the effects of the flow field structure, methanol concentration and its flow velocity on the VA characteristics and AC impedance are analyzed. The experimental results show that the performance of multichannel serpentine flow field methanol fuel cell is better than that of the single channel serpentine flow field methanol fuel cell. The ohmic resistance and electrode reaction impedance of the methanol fuel cell with the multichannel serpentine flow field are small by the analysis of the AC impedance with equivalent circuit. The characteristic of the electric double layer is close to resistance characteristics in the methanol fuel cell with multichannel serpentine flow field. These results are very helpful to optimize the methanol fuel cell performance and its e-lectrode structure.%目的 研究不同实验条件下单通道蛇形流场与多通道蛇形流场直接甲醇燃料电池的性能差异与阻抗变化.方法 实验测量了蛇形流场甲醇燃料电池的伏安特性和交流阻抗,分析了流场结构、甲醇浓度和流速对电池伏安特性和交流阻抗的影响.结果 实验结果表明:多通道蛇形流场甲醇燃料电池的性能优于单通道蛇形流场甲醇燃料电池.通过等效电路分析其交流阻抗发现:多通道蛇形流场甲醇燃料电池的欧姆阻抗、电极反应阻抗都比较小；多通道蛇形流场甲醇燃料电池电极形成的双电层特性趋近电阻特性.结论 阻抗的变化是决定多通道蛇形流场甲醇燃料电池性能高于单通道蛇形流场甲醇燃料电池的重要原因.研究结果对甲醇燃料电池性能和电极优化提供了有益的参考.