Dielectric Materials for Electrical Engineering

Chapter 19

Ion Exchange Membranes for Low Temperature Fuel Cells 1

19.1. Introduction

Since the 1960s, when Loebe in California first showed the application of cellulose membranes in the desalination of water under high pressure gradients, transport studies in membranes have become a flourishing field of research. The process of desalination under a pressure gradient across membranes is called reverse osmosis. The development of membranes from polymers (polyimides, polysulfones, etc.) with good chemical, mechanical and thermal properties promoted the desalination of water by reverse osmosis at competitive prices, for use in households and industries, overtaking the traditionally used flash distillation process [PUS 82], [BAU 62], [CAB 85].

On the other hand, the synthesis of polyelectrolytes centered the interest of numerous researchers because of the potential of these materials, in the form of ionexchange resins and ion-exchange membranes, offer for ionic separations [SAT 02]. One of the applications which raised great interest was the use of ion-exchange membranes for electrical generation systems.

For the last forty years, polymeric proton exchange membranes (PEM) were proposed to be used as solid polyelectrolytes for fuel cells. Amongst their advantages (with respect to inorganic membranes), the ease of production, flexibility and good mechanical properties stand out [GRE 61]. The development of fuel cells in the last twenty years as an economically interesting alternative ...