Model for evaluating degradation of high-temperature fuel cell heat engine systems

A thermodynamic and electrochemical framework with a composite fuel cell for the analysis of the degrading fuel cell heat engine hybrid is used to investigate the effect of temperature and voltage on the performance of high-temperature fuel cell heat engine hybrid systems. In this composite fuel cell a Tafel nickel cermet anode is combined with a ceramic electrolyte and mixed electronic ionic conduction (MIEC) cathode. Activation polarizations are described by three models - Butler-Volmer, Tafel, and MIEC. It is verified from simulation that for hydrogen direct oxidation working reaction (WR) the MIEC-containing fuel cell functions well in the hybrid system. It has found that there is an optimal constant voltage that maximizes power for a hybrid operating at the constant voltage. This simulation method in this paper is a first step in a screening procedure for determining and exploring the system behavior of new fuel cell materials for use in hybrid systems.