Effect of the structural changes of the Ni-Cr anode on the molten carbonate fuel cell performance

Sintering and creep tests and a long-term operation of the single cells were performed to investigate the effect of the structural changes of the Ni-Cr anode on the molten carbonate fuel cell performance. It was found from the sintering and creep tests that the anode had a higher resistance to sintering and creep at the higher firing temperature, and thereby at the lower porosity of the anode and at the higher content of Cr solid solution in the Ni phase. Ni-10 w/o Cr anode fired at 1,000°C under the reduction atmosphere showed the best resistance to sintering and creep among the anodes fabricated at the various conditions. This anode, along with the anode fired at 700°C for comparison, was used for a long-term single cell operation. It was found that the cell performance was significantly affected by the reduction of the anode dimension due to sintering and creep and the formation of the micro-pores through the LiCrO₂ formation followed by the electrolyte re-distribution. Using the 1,000°C anode which had the higher content of Cr solid solution in the Ni phase could reduce such dimension reduction and micro-pore formation, resulting in the better performance during the long-term operation.