Research progress of high temperature proton exchange membranes applied in fuel cells

The fuel cell technology is a highly-efficient clean energy technology which can alleviate the power and environmental problems. Proton exchange membrane fuel cell (PEMFC) is an important type of fuel cell, of which proton exchange membrane is the key component which is proton-conductive and electron-insulating. Elevation of the working temperature of PEMFCs can solve the intractable issues for low-temperature PEMFCs. Therefore, proton exchange membrane materials which can work under high temperature and low relative humidity are required. The main types, preparation and modification methods, and proton exchange mechanisms of high temperature proton exchange membranes were summarized in this review. Proton conductor doped polybenzimidazole (PBI) based membrane materials are potential candidates for high temperature low humidity proton exchange membranes. The preparation, types of proton conductors and performance enhancement methods of PBI based high temperature proton exchange membranes were discussed. The challenges and research trends of high temperature proton exchange membranes were pointed out such as synthesis of new types of proton conductor, improvement of PBI anti-oxidation stability, regulation of membrane microstructure to improve the performance and develop novel polymer electrolytes.