A Comprehensive Investigation on the Enhancing the Thermal Efficiency of Solid Oxide Fuel Cells through Temperature and Pore Diameter Optimization

This study aims to comprehensively analyze the performance of solid oxide fuel cells (SOFCs) operating at high temperatures and converting chemical energy directly into electrical energy, considering the effects of multiple parameters. The cell performance was evaluated in the analysis performed on a cell with an active surface area of ​​0.01 m², a temperature range of 573–1673 K and pore diameters of 3–15 µm. The performance evaluation involved a meticulous examination of activation, ohmic, and concentration losses, along with the determination of cell potential, power density, and thermal efficiency through theoretical analyses. The findings showed that the temperature increase positively affected the cell efficiency up to a certain threshold; it was determined that the thermal efficiency reached its peak especially in the temperature range of 1073 - 1273 K. A 20% efficiency increase was achieved under the conditions of a temperature increase of 210 K, a current density of 10000 A/m² and a pore diameter of 8 µm. While 33.04% and 21.41% efficiency values ​​were obtained with 5 µm and 10 µm pore diameters, respectively, at a constant temperature of 873 K, a 60% increase in pore diameter provided only an 8% efficiency increase, which revealed that the increase in pore diameter had limited and negative effects on efficiency. Unlike the generally single parameter focused cases in the literature, this research demonstrates conclusively that the length of the width diameter will lead to a noticeable decrease in thermal efficiency by providing a joint analysis of multiple variables in the cell.