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

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 LiA_l0.75Mn_0.25O₂. This result suggested that the formation of nano-sized particles confirmed the applicability as a matrix material with excellent electrolyte impregnation.