FUEL CELLS AND IONICALLY CONDUCTIVE MEMBRANES: AN OVERVIEW Eli Korin, Orit Siton and Armand Bettelheim Chemical Engineering Department, Ben-Gurion University of the Negev, P.O.BOX 653, Beer-Sheva 84105, Israel ABSTRACT: An overview regarding different types of fuel cells is presented. Proton conductive materials are used for low and intermediate temperature fuel cells. Such materials (perfluorinated, partially and non-fluorinated sulfonic acid membranes, and composite membranes) are reviewed. Problems (e.g. proper conductivity attained at high hydration, liquid fuel crossover and high cost) encountered when using these materials as membranes in hydrogen/oxygen and direct methanol fuel cells are emphasized. Concepts, recently reported in the literature and dealing with the development of efficient and less expensive membranes/fuel cells, are also described. Keywords: fuel cells, proton exchange membranes, proton conductivity, liquid fuel permeability. 1. FUEL CELLS A fuel cell is an electrochemical device which continuously converts chemical into electric energy as long as the fuel and oxidant are supplied. Unlike engines or batteries, a fuel cell does not need recharging. It operates quietly and efficiently, and when using hydrogen as fuel, it generates only power and drinking water: the so-called "zero emission engine 11 . The main factors which influenced the development of fuel cells in the last decade are the dependence of the industrialized nations on oil and more importantly, the increasing awareness of environmental pollution. Compared 35 Brought to you by | Lulea University of Technology Authenticated | 130.240.43.43 Download Date | 7/29/13 3:21 PM