Degradation Behaviors of Solid Oxide Fuel Cell Stacks in Steady-State and Cycling Conditions

Enhancing the durability of solid oxide fuel cell (SOFC) technologies is a key strategy to accelerate their commercialization and use in several applications. This study aims to evaluate the performance and durability of a 100 W SOFC stack system in steady-state and current load cycling conditions to elucidate the degradation mechanism. The stack temperature and current loads are designated in this study as parameters that greatly affect SOFC degradation. The initial and degraded performances of the SOFC stack are conducted at different stack temperatures in the range of 650–750 °C while testing under constant current load is performed at a fixed current density, 0.33 A·cm–2 and temperature, 750 °C. Degradation tests are conducted based on current load cycling (24 cycles) at a stack temperature of 750 °C and for currents up to 19 A with a ramp rate of 0.5 A·min–1. The results show that the total degradation rates are 54, 297, and 370 mV over 72 h at stake temperatures of 650, 700, and 750 °C, respectively, thus indicating the observed highest degradation owing to the influence of thermal stresses. During the 24 current load cycles, no significant degradation behavior is detected, only steady drops at 0.5%.