低介电常数溶剂环境中电场辅助制备关键组分有序的PEMFC电极

In this project, it is proposed to fabricate a proton exchange membrane fuel cell (PEMFC) electrode with orientated key components in a solution of low relative permittivity aided by an electric field, to enhance the interconnection of channels for electron/proton transfer. Specifically, by using solvent of low permittivity to prepare catalyst ink, assisted by an electronic field, the catalyst particles and ionomers are expected to be oriented in the direction normal to the catalyst layer. By experiment study and theoretical analysis, the physical mechanism and the important factors to influence the orientated catalyst layer structure of PEMFC could be well understood and thereby control the electrode morphology. By virtue of experiment and mathematic models, the effect of the microstructure of the orientated electrode on the polarization loss could be investigated, which is expected to provide theoretical guidance for the optimization of electrode structure parameters. The possible achievements of this project could be meaningful for the development of the fuel cell technique, but also is expected to be lent to the construction of functional composite electrode materials for batteries and electrolysers.

本课题使用低介电性溶剂配制PEMFC催化剂浆液，在催化层（电极）的制备过程中施加电场，使催化剂颗粒和电解质聚合物在垂直于催化层表面方向有序排列，从而提高该方向的电子和质子通道的连通性,即在低介电常数环境下通过电场辅助制备关键组分有序的电极。通过实验研究和理论分析，认识电场和低介电性溶剂作用下PEMFC催化层结构取向的关键物理机制和影响因素，以实现有序结构电极可控制备。通过有序化电极构效关系研究，解释溶剂介电性质对聚合物分子链形态及团聚行为的影响机制，并借助实验和数学模型考察该有序化电极微观结构对极化损失的影响及规律，为电极结构参数的优化提供理论指导。本研究不但对燃料电池技术的发展有一定意义，而且对于其他电池或电解池的电极功能复合材料的制备具有一定的借鉴意义。

本项目针对燃料电池的核心关键部件膜电极展开研究，研究燃料电池催化层的活化极化、传质极化和欧姆极化的关键科学问题。课题组通过在催化层成型过程中引入外加力场，控制控制电极催化层的微观形貌。.使用低介电性溶剂配制PEMFC催化剂浆液，在催化层（电极）的制备过程中施加电场，使催化剂颗粒和电解质聚合物在垂直于催化层表面方向有序排列，从而提高该方向的电子和质子通道的连通性,即在低介电常数环境下通过电场辅助制备关键组分有序的电极。通过实验研究和理论分析，认识电场和低介电性溶剂作用下PEMFC催化层结构取向的关键物理机制和影响因素，以实现有序结构电极可控制备。通过有序化电极构效关系研究，解释溶剂介电性质对聚合物分子链形态及团聚行为的影响机制,并借助实验和数学模型考察该有序化电极微观结构对极化损失的影响及规律，为电极结构参数的优化提供理论指导。.研究结果显示，在电场中的催化剂颗粒和离子聚合物均可实现在电场方向的有序运动。通过电场的作用，可实现对离子聚合物和催化剂碳颗粒的形貌控制。