Synthesis of layered cathode material O.5Li sub(2)MnO sub(3) [middot] 0.5LiMn sub(1/3)Ni sub(1/3)Co sub(1/3)O sub(2) by an improved co-precipitation method for lithium-ion battery

The layered 0.5Li sub(2)MnO sub(3)[middot]0.5 LiMn sub(1/3)Ni sub(1/3)Co sub(1/3)O sub(2) lithium-rich manganese-based solid solution cathode material has been synthesized by two-step co-precipitation method. X-ray diffraction studies reveal that the as-prepared material has a typical layered structure with R-3m and C2/m space group. The surface morphology of the [Mn sub(4/6)Ni sub(1/6)Co sub(1/6)]CO sub(3) precursor and cathode material 0.5Li sub(2)MnO sub(3)[middot]0.5 LiMn sub(1/3)Ni sub(1/3)Co sub(1/3) O sub(2) have been examined using scanning electron microscopy. Electrochemical performances, including discharge capacity, cycling performance and rate capability also have been investigated. The results show that the cathode material 0.5Li sub(2)MnO sub(3)[middot]0.5 LiMn sub(1/3)Ni sub(1/3)Co sub(1/3)O sub(2) prepared by two-step co-precipitation method has a good electrochemical performance, which can deliver a high initial discharge capacity of 276.70 mAh g super(-1) at the current density of 25 mA g super(-1). When cycling at 125 mA g super(-1), the material indicates an initial discharge capacity of 211.31 mAh g super(-1) and 196.64 mAh g super(-1) after 50 cycles, capacity retention is 93.06% and its coulombic efficiencies is greater than 98% at each charge/discharge cycling. Furthermore. the as-prepared material 0.5Li sub(2)MnO sub(3)[middot]0.5 LiMn sub(1/3)Ni sub(1/3)Co sub(1/3)O sub(2) also shows an excellent rate capacity.