Analytically investigating the characteristics of a high-temperature unitized regenerative solid oxide fuel cell

A unitized regenerative solid oxide fuel cell (URSOFC) can be considered as a next-generation power source and a storage device in the future since it can generate electricity in the SOFC mode and also produce H-2/O-2 in the solid oxide electrolyzer cell (SOEC) mode. In this paper, a two-dimensional axisymmetric model is developed to simulate the characteristics of a URSOFC. The performance curves for an in-house button URSOFC under different operating temperatures of 600, 700, and 800 degrees C are measured to validate the present model. Both the measured data and the prediction results reveal the beneficial effects of higher temperature on the cell performance. Based on the results of numerical simulations, the majority of the fuel gas is consumed at the interface of the electrolyte and the electrode, causing a great fuel concentration gradient near the interface. In addition, the predicted cell performance curves in both the SOFC and the SOEC modes correspond well with the measured data, demonstrating the applicability of this model in a button URSOFC. Copyright (c) 2013 John Wiley & Sons, Ltd.