High performance LiNi0.5Mn1.5O4 cathode materials synthesized by a combinational annealing method

High performance LiNi0.5Mn1.5O4 was prepared by a combinational annealing method. All samples were characterized by X-ray diffraction, infrared, and cell measurements. With increasing the annealing time at 600 °C, LiNi0.5Mn1.5O4 showed a decreased lattice parameter and an enhanced Ni-ordering. The electrochemical property of LiNi0.5Mn1.5O4 was optimized by controlling the annealing time. It was found that after annealing at 600 °C for 8 h, LiNi0.5Mn1.5O4 can discharge up to 138 mA h g−1 with a superior cycling performance at the rate of 5/7 C. High-rate test indicated that LiNi0.5Mn1.5O4 exhibited excellent electrochemical performance when charged and discharged at 1.2 C and 2.5 C, respectively. The findings reported in this work are expected to pave the way for the practical application of LiNi0.5Mn1.5O4.