INFLUENCE OF HYDROGEN CONCENTRATION IN AN Ar–H₂ MIXTURE ON THE ELECTRICAL PROPERTIES  OF SOLID OXIDE FUEL CELLS

Abstract

 Fuel cells are today among the most efficient and environmentally friendly devices for the production of electricity, which are developing rapidly and are already in the early stages of commercialization. Solid oxide fuel cells (SOFCs) are largely promising as they show the highest efficiency and fuel flexibility (H₂, С_nH_m, CO, etc.) and do not need platinum group catalysts. Much attention is paid to improving the structure of SOFCs to increase their electrical properties. Different research groups commonly study the electrical properties of SOFCs under different conditions depending on the available equipment and the capabilities of their laboratories; this complicates the overall comparison of the electrical properties of fuel cells. In this regard, this research focuses on establishing the dependence of the specific electric power (P_0.7) under 0.7 V voltage of SOFCs on the hydrogen concentration in the model fuel (a mixture of hydrogen and inert gas), other test conditions being equal. The specific electric power P_0.7 was chosen as one of the most important indicators for SOFC operation in power systems. The experimental data on the dependence of P_0.7 on the hydrogen concentration (C_H2) in the model fuel for different SOFCs were fitted with the least squares method to polynomial, logarithmic, and linear functions, with calculation of the factor of coincidence (determination factor R²) with the experimental data. The quadratic and linear fitting functions were found to be the most accurate among the functions considered and showed an average relative approximation error of no more than 9 and 12%, respectively. The prospects of the proposed hypothesis are that the fitted dependence of the electrical indicators of SOFCs can be used not only to predict the electrical properties of SOFCs in different operating conditions but also to facilitate the comparison of their electrical properties.