Perspectives on Membrane Development for High Temperature Proton Exchange Membrane Fuel Cells

High temperature proton exchange membrane fuel cells (HT-PEMFCs) are a promising energy conversion technology due to their quick reaction kinetics, high tolerance to CO impurities, and ease of heat and water management. Nevertheless, the practical implementation of this technology is limited since traditional proton exchange membranes (PEMs) exhibit significantly reduced performance at high temperatures and low humidity. In this extreme situation, researchers have concentrated on investigating new membranes through the creation of novel polymers and fillers or by suggesting sophisticated modification processes, with the goal of attaining high proton conductivity, stable mechanical properties, and tremendous temperature tolerance. This Review focuses on the latest advancements in four PEM domains: (1) perfluorosulfonic acid (PFSA)-based PEMs; (2) aromatic polymer-based PEMs; (3) polybenzimidazole (PBI)-based PEMs; and (4) polymer of intrinsic microporosity (PIM)-based PEMs. We describe and provide an overview of the preparation methods, mechanistic analysis, and core characteristics (proton conductivity and peak power density) of the aforementioned membrane materials. Furthermore, prospective research paths and challenges in the development of PEMs toward practical applications are also suggested.