Nanostructured Organic-Inorganic Hybrid Membranes for High-Temperature Proton Exchange Membrane Fuel Cells

This chapter reviews on the most common nanostructured hybrid membranes based on Nafion and polybenzimidazole (PBI) polymeric matrix modified by hydroscopic metal oxides, organic functionalized inorganic materials, and inorganic proton conductors. The nanostructured composite membranes show significantly improved proton conductivity and cell performance at elevated temperatures and reduced relative humidity (RH), demonstrating their promising potential in the development of high-temperature proton exchange membrane fuel cells (HT-PEMFCs). Besides Nafion, alternative hydrocarbon polymers have been developed as the polymer matrix for the organic-inorganic hybrid nanocomposite membranes. This chapter shows that nanostructured organic-inorganic hybrid composite membranes combine the advantages of the easy handling and mechanical flexibility of polymer membrane and the high water retention and proton conductivity of the inorganic nanoparticles with and without functionalization, demonstrating their promising potential as HT-PEMs at elevated temperatures and low RH conditions.