Synthesis of Mn-, Ni-Doped LiAlO₂ Matrix for Molten Carbonate Fuel Cell

Abstract

The phase stability of electrolyte matrix was improved by metal dopant materials which are Ni and Mn. The Ni-, Mn-doped LiAlO2 and dopant-free LiAlO2 were prepared by the mechanochemical process (MCP). The effects of dopant material, molar ratio and type of precursor were investigated after heat treatment at 700 and 800 °C. As a results, the Mn-doped LiAlO2 prevents phase transition even at higher operating temperature. Also, the stability was increased when Mn4+ ion was adapted as a precursor source than Mn3+ ion and the minimum Mn content to maintain the α-phase after heat treatment at 800 °C is found to be LiAl0.75Mn0.25O2. This result suggested that the formation of nano-sized particles confirmed the applicability as a matrix material with excellent electrolyte impregnation.