论文部分内容阅读
Spherical cathode material LiNi0.5Mn1.5O4 for lithium-ion batteries was synthesized by hydroxide coprecipitation 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 patts reveal that the structure of prepared LiNi0.5Mn1.5O4 cathode material belongs to Fd3m space group.Electrochemical tests at 25 ℃ show that the LiNi0.5Mn1.5O4 cathode material prepared after annealing at 600 ℃ 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 ℃,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 112.4mAh.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.