Fuel cell materials and components

Fuel cells offer the possibility of zero-emissions electricity generation and increased energy security. We review here the current status of solid oxide (SOFC) and polymer electrolyte membrane (PEMFC) fuel cells. Such solid electrolyte systems obviate the need to contain corrosive liquids and are thus preferred by many developers over alkali, phosphoric acid or molten carbonate fuel cells. Dramatic improvements in power densities have been achieved in both SOFC and PEMFC systems through reduction of the electrolyte thickness and architectural control of the composite electrodes. Current efforts are aimed at reducing SOFC costs by lowering operating temperatures to 500-800 degreesC, and reducing PEMFC system complexity be developing 'water-free' membranes which can also be operated at temperatures slightly above 100 degreesC. (C) 2003 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.