Investigation on liquid combustion synthesis of spinel LiMn2O4 and Li4Mn5O12

Spinel LiMn2O4 and Li4Mn5O12 were synthesized by liquid combustion synthesis using urea as fuel and lithium nitrate (manganese nitrate) and lithium acetate (manganese acetate) as raw materials, respectively. The results indicated that LiMn2O4 as main phase in nitrate system and as single phase in acetate system with the mole ratio of Li:Mn=1:2 was investigated, and only Li4Mn5O12 single phase in both nitrate and acetate system with the molar ratio of Li:Mn = 1:1 was obtained. When the molar ratio of Li:Mn:urea is 1:2:5, the highest combustion temperature was 850°C in acetate system and 1433°C in nitrate system. Better crystallinity of spinel lithium manganese oxides in acetate system was gained than that in nitrate system. The crystal structures of LiMn2O4 and Li4Mn5O12 were closed to perfect with the increment of urea.