Molten Borates Fuel Cells — Mathematical modeling and identification of performances

Abstract

The research presents an overview of the possibilities of using boron-containing compounds as electrolytes for fuel cells. The main assumption here is to develop a molten carbonate fuel cell type power source, where the molten electrolyte is kept by a ceramic matrix between the electrodes. In the cases which are described in this study, attempts were made to develop electrolytes based on borates. Whereas the reported studies contain very little information on this subject, it was possible to identify several promising compounds and to extrapolate their performance to higher temperatures. Reported data on the temperature at eutectic points suggest that the operating range of such electrolytes is at a level like the molten carbonate fuel cell. The study presents a proposal for a mathematical model of a new type of fuel cell based on molten borates. The mathematical model is based on the reduced order model, supplemented with the influence of the ceramic matrix on the resulting ionic conductivity of the electrolyte layer. The model was used to determine potential performances for a few selected borates and a sensitivity analysis of selected geometric parameters was performed for the best of them. The results obtained were compared against the standard molten carbonate fuel cell.