Synthesis and characterization of Li(Li0.23Mn0.47Fe0.2Ni0.1)O2 cathode material for Li-ion batteries

A new cobalt free LiFeO2-Li2MnO3 based solid solution with a composition of Li(Li0.23Mn0.47Fe0.2Ni0.1)O-2 is developed to obtain high capacity and better cycling stability. A new citric acid assisted sol-gel process including three-step of preparation of wet gel-formation of spray-dried gel-annealing at high temperature is proposed. The results show that uniform Li(Li0.23Mn0.47Fe0.2Ni0.1)O-2 solid solution with pure hexagonal phase (or monoclinic phase) can be successfully prepared even at low temperature of 600 degrees C. Increasing the annealing temperature can improve the crystallization and cation-ordering of Li(Li0.23Mn0.47Fe0.2Ni0.1)O-2, but severe agglomeration to form large size secondary particles (1-10 mu m) over 750 degrees C leads to the decreased capacity. The sample annealed at optimized temperature of 700 degrees C shows uniform fine well-crystallized particles with 100-200 nm diameters, high capacity of 277.4 mAh g(-1) at 10 mA g(-1) (0.04C) and better cycling stability at different rate. It presents a capacity of 188 mAh g(-1) at 75 mA g(-1) (0.3C) and 90.4% capacity retention after charge-discharged 100 cycles. (C) 2013 Elsevier B.V. All rights reserved.