LiMn_1.95M_0.05O₄ (M: Al, Co, Fe, Ni, Y) cathode materials prepared by combustion synthesis

Spinel LiMn_1.95M_0.05O₄ (M: Al, Co, Fe, Ni, or Y) is prepared by a combustion synthesis, which is a simple, rapid and cost-effective process for obtaining oxide powders. The spinel is obtained by combustion of lithium hydroxide, manganese nitrate, M-nitrates, and urea at about 280°C for 1 min. Well-defined spinel LiMn_1.95M_0.05O₄ was obtained by further heat-treatment at 800°C for 10 h. The synthesized LiMn_1.95M_0.05O₄ shows lower initial capacities, viz. 90-132 mAh/g than undoped LiMn₂O₄. The latter has an initial capacity of 146 mAh/g which fades to 100 mAh/g with cycling. On the other hand, LiMn_1.95Co_0.05O₄, LiMn_1.95Ni_0.05O₄, and LiMn_1.95Y_0.05O₄ display better cycleability than LiMn₂O₄.