Modeling investigation of Sm0.5Sr0.5CoO3-δ-Ce0.8Sm0.2O2-δ cathode for proton-conducting ceramic fuel cell

Simulation of proton ceramic fuel cell is of great importance in understanding their working mechanisms. Cathode activation polarization is a critical concern in the simulation. In this paper, Sm0.5Sr0.5CoO3-delta-Ce0.8Sm0.2O2-delta cathode is selected as studied case. The effective reaction order, which is the exponential of the oxygen partial pressure in cathode Butler-Volmer equation, is determined via our model. The dominant process in cathode reaction is investigated and identified. Among the involved reaction steps, model result points out that the surface diffusion of absorbed oxygen ion is dominant, which is in accord with the report. Moreover, single button cells with BaCe0.7Zr0.1Y0.2O3-delta electrolyte and Sm0.5Sr0.5CoO3-delta-Ce0.8Sm0.2O2-delta cathode are prepared, and the measured cell output voltages are compared with the simulated ones. The predicted cell outputs via our full cell simulation match the measurements under diverse experimental settings, suggesting that the method and parameters in our simulation are applicable. Our models facilitate both the analysis of experimental results and the development of proton-conducting solid oxide fuel cell model.