Affiliation:
1. School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative Molecules Center of Hydrogen Science Shanghai Key Lab of Electrical Insulation & Thermal Aging Shanghai Jiao Tong University Shanghai 200240 China
2. School of Energy Power and Mechanical Engineering North China Electric Power University Beijing 102206 China
3. Materials Sciences Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
Abstract
AbstractThe significant role of the cathodic binder in modulating mass transport within the catalyst layer (CL) of fuel cells is essential for optimizing cell performance. This investigation focuses on enhancing the membrane electrode assembly (MEA) through the utilization of a short‐side‐chain perfluoro‐sulfonic acid (SSC‐PFSA) ionomer as the cathode binder, referred to as SSC‐MEA. This study meticulously visualizes the distinctive interpenetrating networks of ionomers and catalysts, and explicitly clarifies the triple‐phase interface, unveiling the transport‐friendly microstructure and transport mechanisms inherent in SSC‐MEA. The SSC‐MEA exhibits advantageous microstructural features, including a better‐connected ionomer network and well‐organized hierarchical porous structure, culminating in superior mass transfer properties. Relative to the MEA bonded by long‐side‐chain perfluoro‐sulfonic acid (LSC‐PFSA) ionomer, noted as LSC‐MEA, SSC‐MEA exhibits a notable peak power density (1.23 W cm−2), efficient O2 transport, and remarkable proton conductivity (65% improvement) at 65 °C and 70% relativity humidity (RH). These findings establish crucial insights into the intricate morphology‐transport‐performance relationship in the CL, thereby providing strategic guidance for developing highly efficient MEA.
Funder
National Key Research and Development Program of China
Science and Technology Commission of Shanghai Municipality