Emerging membranes for electrochemical systems - Part II. High temperature composite membranes for polymer electrolyte fuel cell (PEFC) applications

This paper shows an exhaustive presentation and complementary discussions on various aspects of works done recently on the developments of composite membranes for polymer electrolyte fuel cell (PEFC) applications. The limitations of per-fluorinated polymer electrolyte membranes to low temperature (<80degreesC) PEFC applications are discussed. Research on alternative proton conducting membranes to the per-fluorinated membranes for high temperature PEFC applications are shown. The development of the bis[(perfluoroalkyl)sulfonyl]imide as an alternative membrane to the per-fluorinated family is indicated. The concept of synergetic composite membranes for high temperature PEFC applications is introduced. Recent approaches and concepts for the elaboration of new composites membranes are described. The following aspects of the researches on proton conducting proton membranes are discussed: (i) macro- and nano-composites per-fluorinated ionomer composite membranes (PFICMs); (ii) partially per-fluorinated composite membranes; and (iii) non-per-fluorinated composite membranes. Results based on our original works are also presented. In each case, the type of the composite membrane is well described. Accordingly, organic-inorganic, organic-organic, organic-acid and organic-base complexes composite membranes are considered. The challenges related to these developments are discussed. Prospective for future developments on effective composite membranes for high temperatures PEFC applications are discussed. (C) 2003 Published by Elsevier B.V.