Fuel cells, 26-27, Chapter attributes

A number of cells have been developed which make use of the oxygen of the air as the cathodic reagant. These so-called air-depolarized cells are examples of hybrid cells, which are discussed more fully in Chapter 9. Many recent advances in metal-air batteries can be attributed to the research carried out in the 1960s on high current density air electrodes for ambient hydrogen/oxygen fuel cells using aqueous electrolytes. 

Abstract The polymer electrolyte fuel cell (PEFC) consists of disparate porous media microstructures, e.g. catalyst layer, microporous layer, gas diffusion layer, as the key components for achieving the desired performance attributes. The microstmcture-transport interactions are of paramount importance to the performance and durability of the PEFC. In this chapter, a systematic description of the stochastic micro structure reconstmction techniques along with the numerical methods to estimate effective transport properties and to study the influence of the porous structures on the underlying transport behavior is presented. 

Abstract In this chapter, we highlight some critical aspects of materials for use in solid oxide fuel cells. In relation to oxide ion conducting electrolytes, we address topics including clustering of defects in zirconias and the resultant limitations on ionic conductivity. We also discuss the ionic conduction window for various electrolyte systems. The positive and negative attributes of different anode materials are considered, highlighting the opportunities for alternative materials to be utilised in certain parts of the SOFC system. Some suitable system concepts are presented and a strategy to optimise performance and durability in the same electrode structures is presented. 

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