Creation of Novel Ion Conducting Membrane by Nano-Micro Structural Control

制备了由质子导电聚合物和多孔基质组成的新型直接甲醇燃料电池（dmfc）质子导电膜。采用二氧化硅或聚酰亚胺作为复合膜的基体，制备了具有良好机械强度的三维有序大孔（3DOM）膜。由于基质对聚合物膨胀的机械抑制，复合膜具有较高的尺寸稳定性。结果，甲醇的渗透性不到Nafion【〇！】的十分之一。R】膜和高性能的细胞通过进料所需的高浓度甲醇溶液（10 mol dm-3）首次成功实现。复合膜的组成部分价格低廉，因此生产成本也可以降低到nation的十分之一以下【〇！膜。利用透射电子显微镜观察聚合物电解质在复合膜中的填充状态，并与D01组进行了联合研究。从而明确了复合膜的纳米结构与复合膜性能之间的关系，提高了复合膜的性能。作为另一种电解质膜，对C01族合成的新型室温熔盐填充的3DOM硅基进行了评价。所制备的复合膜在干燥和高温条件下稳定工作100 h以上，为电动汽车高温DMFC的实现奠定了基础。还进行了提高细胞性能的研究。交流阻抗测试表明，膜与催化剂层之间的质量对电池性能有很大影响。作为一种解决方案，我们对3DOM二氧化硅进行了磺酸基表面改性，并成功地提高了电池性能。本文还研究了利用电泳沉积（EPD）工艺在膜上制备催化剂层的方法。与普通方法（即贴花转移工艺）制备的催化剂层相比，EPD工艺制备的催化剂层均匀且多孔。该结构有利于气体扩散，Pt利用率提高76%。因此，EPD工艺制备的MEA与普通MEA相比，在铂用量为一半的情况下表现出更高的电池性能。后一种工艺已被电化学学会作为技术亮点介绍到世界各地，引起了广泛的关注。少

Novel proton conducting membranes composed of proton conducting polymers and porous matrices were prepared for direct methanol fuel cells (DMFCs). As the matrix for the composite membrane, a three-dimensionally ordered macroporous (3DOM) membrane with adequate mechanical strength was successfully obtained by use of silica or polyimide. Due to mechanical suppression of polymer expansion by the matrix, the composite membrane exhibited high dimensional stability. As a result, the methanol permeability less than a few tenths of that of Nafion【○!R】 membrane and high cell performance by feeding a desired high-concentrated methanol solution (10 mol dm-3) were successfully achieved for the first time ever. The components of the composite membrane were inexpensive, so that the production cost could be also decreased less than a few tenths of that of Nafion【○!R】 membrane. The filling state of the polymer electrolyte in the composite membrane was revealed by transmission electron microscope obser … More vation, which was conducted as a joint study with Group D01. Therefore, the relationship between the nano-structure of the composite membrane and the resulting properties became clear and the membrane properties could be improved. As another type of the electrolyte membrane, the 3DOM silica matrix filled with a novel room-temperature molten salt that was synthesized by Group C01, was evaluated. The obtained composite membrane worked stably over 100 h under dry and high-temperature condition, suggesting the realization of high temperature DMFC for electric vehicles.Researches for improving cell performance were also conducted. It was appeared that the quality between the membrane and a catalyst layer greatly influenced the cell performance by A.C. impedance measurement. As one of solutions, we performed a surface modification of the 3DOM silica by sulfonic acid groups, and the cell performance was successfully enhanced. Application of electrophoretic deposition (EPD) process to fabricate a catalyst layer onto the membrane was also studied as another method. The obtained catalyst layer by the EPD process was uniform and porous compared to that prepared by an ordinary method, i.e. a decal transfer process. This structure was favorable to gas diffusion, resulting in improvement of Pt utilization up to 76%. Accordingly, the MEA prepared by the EPD process exhibited higher cell performance with half amount of Pt loadings compared to the ordinary one. The latter process has been introduced all over the world by Electrochemical Society as Technical highlight and has attracted much attention. Less