Electrochimica Acta, Vol.318, 560-571, 2019
New approaches for the determination of electrochemical parameters in the model of proton-conducting solid oxide fuel cell
Proton-conducting solid oxide fuel cell is an electrical energy generation device with great potentials in the industrial and civil applications. The values of empirical parameters adopted in the corresponding simulations significantly determines the quality and reliability of the modeling results. Two new and practicable approaches are proposed in this paper, in order to accurately evaluate several critical electrochemical parameters in the relevant simulations. According to our models, effective hole conductivity of the electrolyte under working conditions, along with cathode electrochemical reaction order, are directly derived from the experiment. To examine the proposed approaches, single cells with BaCe0.8Sm0.2O3-delta electrolyte and Sm0.5Sr0.5CoO3-delta-BaCe0.8Sm0.2O3-delta cathode are manufactured, further the related experiments are performed as case studies. To determine the cathode activation overpotentials for cells with different particle sizes, a transferable parameter named TPB-specific exchange current density is introduced, and an expression which is much more convenient for numerical simulation of the cathode activation overpotential than the previously reported one is put forward in our model. These proposed expressions and parameters possess desirable transferability, and accurate numerical predictions of the cell output performances are achieved for both our and reported experiments. Then the influences of the involved polarizations are explored. Emphasis is drawn on the electrolyte hole conductivity. Its impact on the cell performance is non-negligible particularly under relatively high temperature and low output current, and hence has to be considered seriously in the simulation. (C) 2019 Elsevier Ltd. All rights reserved.