Gas electrodes with nickel based current collectors for molten carbonate electrolyte thermo-electrochemical cells

Abstract

Thermo-electrochemical cells with inexpensive molten carbonate electrolyte and (CO2|O2) gas electrodes allow the possible conversion of high temperature waste heat from industrial processes into electricity. The cell containing eutectic (Li,Na)2CO3 electrolyte with solid MgO dispersion delivers a large Seebeck coefficient of −1.7 mV/K. At present, the (CO2|O2) gas electrodes use metallic gold as current collectors in order to avoid the formation of interfering oxide layers during operation. For further reduction in energy generation cost, the gold current collectors should be replaced with an inexpensive and stable alternative. In this study, the suitability of the (molten carbonate fuel cell) MCFC's nickel-based cathodes to operate the molten-carbonate thermo-electrochemical cell, was investigated. Ni current collectors were examined in two different states, as NiO and as lithiated NiO (LixNi1−xO). The NiO phase shows higher stability than the LixNi1−xO while the Seebeck coefficient remains above −1.2 mV/K.