Degradation of the components in molten carbonate fuel cells with Li/Na electrolyte

The Li/Na carbonate is expected to be the one of the candidates for the advanced electrolyte of Molten Carbonate Fuel Cells (MCFC) under pressurized operation. After long term operation of cells with the Li/Na carbonate, the degradation of cathodes, matrices and cathode current collectors are analysed. With the Li/Na carbonate, the particle growth of NiO in cathodes was suppressed due to NiO being less soluble. Moreover, there were no detectable effects on both the particle growth and the phage transformation of gamma LiAlO2 in the matrices. Effects on the corrosion penetration and the electrolyte losses of the cathode current collectors were not detected. Therefore, the MCFCs with the Li/Na carbonate are expected to have a longer endurance and a lower decay rate compared with conventional cells with Li/K carbonate, because of less dissolution of the NiO cathode related to both short circuiting and the increase of polarization due to structural changes of the cathodes.