Recent advances in sulfonated poly ( ether ether ketone ) based proton exchange membranes for high temperature fuel cells

Proton exchange membranes (PEMs) play an important role in the fuel cell systems. A good PEM must meet a series of requirements such as high proton conductivity, excellent mechanical strength and stability, chemical and electrochemical stability, low fuel crossover, etc. Nafion is currently the most commercially utilized electrolyte membranes for polymer electrolyte fuel cells, with high chemical stability, proton conductivity and strong mechanical properties. While perfluorinated polymer electrolytes have satisfactory properties for fuel cell applications, they limit commercial use due to significant high costs as well as reduced performance at high temperatures and low humidity. A promising alternative to obtain high performance protonconducting polymer electrolyte membranes is through the use of hydrocarbon polymers. SPEEK blends show a great potential to substitute Nafion in high-temperature operating conditions. In this paper, we focus on the recent advances in development of novel SPEEK blends that work well under elevated temperature and/or low relative humidity.