Investigation Of Short-Side-Chain Ionomer And Membrane For Proton Exchange Membrane Fuel Cells

Abstract

Proton exchange membrane (PEM) fuel cells have been progressively designed to become suitable for hightemperature operation to achieve further performance improvements. However, the current state-of-the-art fuel cell materials, such as long-side-chain (LSC) ionomers and membranes, are not suitable for high-temperature operation, requiring development and investigation of alternative materials. In this study, short-side-chain (SSC) membrane and ionomer are considered as potential materials, and performance of a membrane-electrode assembly (MEA) manufactured with the SSC ionomer and membrane is experimentally investigated in a scaled-up fuel cell (45 cm 2 ). Comparison is made with an MEA based on the LSC ionomer and membrane under identical preparation and testing conditions. The catalyst layers (CLs) made of either SSC or LSC ionomer are characterized through scanning electron microscopy (SEM) to understand their surface morphology and microstructure. Results show that the SSC ionomer embedded in the CL provides much more uniform surface morphology and well-proportioned microstructural characteristics than its LSC counterpart. Further, the MEA based on SSC ionomer and membrane demonstrates considerable performance superiorities under all the applied operating conditions. Furthermore, the performance of the MEA based on the SSC ionomer and membrane is found to be less sensitive to changes in operating conditions.