Properties of NiO cathode coated with lithiated Co and Ni solid solution oxide for MCFCs

The short circuit of cells due to the dissolution and the deposition of NiO in a molten carbonate is a big problem that has to be resolved if we want to use Molten Carbonate Fuel Cells (MCFCs) for long-term operation. To resolve this problem, we have proposed a new cathode structure in which NiO grains have been coated with LiCoO2 grains by usual tape casting method, because LiCoO2 is more stable in a carbonate melt than NiO. CoO/NiO composites with 5 to 20 mass% Ca could be formed by using the CoO/Ni composite particles; As confirmed by SEM, these composites consisted of NiO cores covered with the outer layer of Li(Co, Ni) oxide. The stability of the lithiated CoO/NiO composite with 5 mass% CoO was significantly improved in comparison with that of conventional NiO for MCFCs. The lithiated CoO/NiO composite was also successfully formed by in-situ oxidation and lithiation process. We thought that this composite cathode material consisting of NiO core covered with Li(Co, Ni) oxide will be adopted as the new cathode for MCFCs. (C) 2000 Elsevier Science S.A. All rights reserved.