Development of in-situ/ex-situ electrochemical measurement system for polymer electrolyte membrane fuel cells

通过发展原位和非原位电化学测试技术，建立了聚合物电解质膜燃料电池（PEMFC）电化学测试系统。到目前为止，PEMFC的电池性能已经通过单电池的I-V特性来评估。本研究成功地建立了基本的方法，以测量电池中使用的每种材料在电池运行环境下正确。主要研究成果归纳如下。首先，通过开发新型多孔微盘电极和多孔云母电极，评价了粉末催化剂单独和催化剂/PEM层状结构的电化学性能。第二，通过采用一组微电极，PEM在厚度方向上的精确质子电导率变得可用。当测得的电导率与电流中断技术评估相比，质子电导率的大小是一致的。第三，利用微盘电极的微定位特性，提出了一种在质子交换膜上进行酒精渗透评价的新方法。这使得能够在PEM进行定量交叉分析。其次，根据光谱电化学测量，研究了作为新燃料候选物的芳香醇的氧化还原机理。最后，聚合物电解质膜的离子电导率已解决采用叉指微阵列电极通过改变水：甲醇混合比，这是值得操作的直接甲醇燃料电池（DMFC）。总之，通过设计原位/非原位电化学测试系统来评价PEMFC中的功能材料，大大提高了对材料和电池系统的电化学研究。

Electrochemical measurement system for polymer electrolyte membrane fuel cells(PEMFCs) has been constructed by developing in-situ and ex-situ electrochemical techniques. Thus far, cell performances of PEMFCs have been evaluated by I-V characteristics of the single cell. The present study has succeeded to establish fundamental methods to measure each material used in the cell properly under the cell-operation environments. Main research results are summarized as follows. First, by developing novel porous-microdisc electrode and porous-microring electrode, electrochemical properties of powder catalyst alone and catalyst/PEM layered structure have been estimated. Second, precise proton conductivity of PEM in thickness direction has become available by employing a set of microelectrodes. When the measured conductivity was compared with that assessed by the current interruption technique, the magnitudes of proton conductivities were well agreed. Third, a new method for alcohol crossover evaluation at a PEM has been attained, utilizing a microdisc electrode based on its micro-positioning feature. This enabled a quantitative crossover analysis at the PEM. Next, redox mechanism of an aromatic alcohol as a new fuel candidate has been investigated according to a spectroelectrochemistry measurement. Finally, ionic conductivity of polymer electrolyte membrane has been resolved employing an interdigitated microarray electrode by changing a water : methanol mixture ratio, which is worthwhile for operating the direct methanol fuel cell(DMFC). In conclusion, by designing in-situ/ex-situ electrochemical measurement system to evaluate the functional materials in the PEMFC, electrochemical study for the materials and the cell systems have been greatly improved.