LiFeO2–LiCoO2–NiO materials for Molten Carbonate Fuel Cell cathodes. Part I: Powder synthesis and material characterization

Ternary compositions of LiFeO2, LiCoO2 and NiO are expected to posses desirable characteristics for the Molten Carbonate Fuel Cell (MCFC) cathode application. This paper presents a detailed description of the synthesis of LiFeO2–LiCoO2–NiO powders as well as dense sintered materials together with a brief discussion on the common aspects and trends observed in the characterization of these materials for MCFC cathode application. Feasibility of two wet-chemical powder preparation techniques, the Pechini method and the glycine–nitrate method, was investigated to obtain powders with characteristics appropriate for cathode fabrication. Materials in the LiFeO2–NiO binary system and five ternary sub-systems, each with a constant molar ratio of LiFeO2/NiO while varying LiCoO2 content, were studied. Powders with characteristics appropriate for MCFC cathode fabrication could be obtained by the Pechini method. The particle size of LiFeO2–LiCoO2–NiO powders considerably depends on the calcination temperature and the material composition. The electrical conductivity study reveals the ability of preparing LiFeO2–LiCoO2–NiO materials with adequate electrical conductivity for MCFC cathode application.