Properties of the reinforced composite membranes formed by melt soluble ion conducting polymer resins for PEMFCs

Abstract

We have developed a fabrication method of reinforced composite membranes having a thickness of ca. 30 mum for use in PEMFCs. The reinforced composite membrane (RCM) was prepared by placing a pair of films of perfluorosulfonyl fluoride resin (equivalent weight = 1000, -SO2F) on both side of microporous expanded PTFE (ePTFE) sheet followed by hot-pressing and its electrochemical, hydrolytic and mechanical properties were measured and compared with those of homogeneous resin membrane (EW = 1000) made of perfluorosulfonyl fluoride resin and Nafion 115((R)) (EW = 1100) membrane. While mechanical and hydrolytic properties of the RCM were higher than those of resin membrane, but still lower than those of Nafion 115((R)) membrane. Ionic conductance of the RCM, however, was about 2.5 times higher than that of Nalion 115((R)), due to a low thickness and EW of RCM. (C) 2004 Elsevier Ltd. All rights reserved.