Some more considerations on the optimization of cermet solid oxide fuel cell electrodes

Limiting behaviour and optimization considerations are discussed on the basis of an analytical model (Costamagna, Costa and Antonucci, Electrochim. Acta, 43, 375 (1997); Costamagna, Antonucci, Costa and Arato, Proc. IEA Workshop, Les Diablerets, Switzerland, January 1997, p. 196) for cermet solid oxide fuel cell electrodes. The results show that it is not possible to optimize the overall electrode conductivity, taking polarization and ohmic effects into account (Costamagna, Costa and Antonucci, Electrochim. Acta, 43, 375 (1997)), and the electrode utilization at the same time. Under conditions of optimal conductivity, the electrochemical reaction is unevenly distributed and only a fraction of the electrode thickness effectively supplies electrical current; on the contrary, thicknesses small enough for a uniform current distribution to result are sub-optimal from the point of view of the electrode conductivity. (C) 1997 Elsevier Science Ltd. All rights reserved.