以掺氢天然气为燃料直接内重整固体氧化物电池堆的稳定性OA北大核心CSTPCD

In this work,the long-term stability and degradation mechanism of a direct internal-reforming solid oxide fuel cell stack(IR-SOFC stack)using hydrogen-blended methane steam reforming were investigated.An overall degradation rate of 2.3％.kh-1 was found after the stack was operated for 3000 hours,indicating a good long-term stability.However,the voltages of the two cells in the stack were increased at the rates of 3.38 mV kh-1 and 3.78 mV·kh-1,while the area specific resistances of the three metal interconnects in the stack were increased to 0.276 Ω·cm2,0.254Ω·cm2 and 0.249 Ω·cm2.The degradation of the stack might be caused by segregation of chromium on the surface of metal interconnects and the formation of SrCrO4 insulating phase in the current collecting layer of the cathode,which result in an increase in the interfacial resistance and a decrease in the stack performance.The long-term performance of a flat-tube IR-SOFC stack could be further improved by suitably coating the metal interconnect surface.This work provides theoretical and experimental guideline for the application of hydrogen-blended methane steam reforming in flat-tube IR-SOFC stacks.