Synthesis and electrochemical performances of high-voltage LiNi0.5Mn1.5O4 cathode materials prepared by hydroxide co-precipitation method

Spherical cathode material LiNi0.5Mn1.5O4 for lithium-ion batteries was synthesized by hydroxide co-precipitation method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical measurements were carried out to characterize prepared LiNi0.5Mn1.5O4 cathode material. SEM images show that the LiNi0.5Mn1.5O4 cathode material is constituted by micro-sized spherical particles (with a diameter of around 8 μm). XRD patterns reveal that the structure of prepared LiNi0.5Mn1.5O4 cathode material belongs to Fd3m space group. Electrochemical tests at 25 °C show that the LiNi0.5Mn1.5O4 cathode material prepared after annealing at 600 °C has the best electrochemical performances. The initial discharge capacity of prepared cathode material delivers 113.5 mAh·g−1 at 1C rate in the range of 3.50–4.95 V, and the sample retains 96.2% (1.0C) of the initial capacity after 50 cycles. Under different rates with a cutoff voltage range of 3.50–4.95 V at 25 °C, the discharge capacities of obtained cathode material can be kept at about 145.0 (0.1C), 126.8 (0.5C), 113.5 (1.0C) and 112.4 mAh·g−1 (2.0C), the corresponding initial coulomb efficiencies retain above 95.2% (0.1C), 95.0% (0.5C), 92.5% (1.0C) and 94.8% (2.0C), respectively.