Trends in Polymer Electrolyte Membranes for PEMFC

In this chapter research trends followed by various scientific groups for the development of polymeric membranes have been described and reviewed. Most notably, the developments made at Ballard Advanced Materials (BAM) and some of their results are discussed. In general three different approaches have been followed worldwide by various research groups for the development and conception of alternative membranes. These approaches include: (1) modifying perfluorinated ionomer membranes; (2) functionalization of aromatic hydrocarbon polymers/ membranes; and (3) composite membranes based on solid inorganic proton conducting materials and the organic polymer matrix or prepare acid-base blends and their composite to improve their water retention properties. The current trend is for the composite and hybrid membranes, which combines the properties of both the polymeric component and inorganic part. The most widely studied polymer after Nafion is the sulfonated polyether-ether ketone (SPEEK), as it has a high potential for commercialization. A number of research projects are currently undergoing dealing with the SPEEK polymer in various research labs.