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The Future of Polymers for Fuel Cell Membranes

In this volume, we have assembled a collection of reviews of polymer aspects of proton exchange membrane (PEM) fuel cells. This subject has been reviewed fairly extensively of late. However, we hoped to add a different perspective by focusing on critical practical issues and the main approaches to achieving progress. In this light, the present introduction will provide a thumbnail sketch of polymer electrolyte aspects of fuel cells, based on application. The primary requirements of membranes and the state of progress toward meeting those requirements vary substantially depending on the target application of the membrane. We will attempt to provide the reader with some insight into these aspects. Along the way, we will consider the interplay between the fuel cell system and polymer electrolyte components (in the interests of full disclosure: this discussion is somewhat opinionated and, of course, may be somewhat shortsighted or even wrong). The general “wish list” for membrane attributes for fuel cells is something like the following: