TiO_2包覆LiNi_(0.5)Mn_(0.5)O_2的结构和电化学性能研究

Structural characterization and electrochemical performance of TiO_2-coated of LiNi_(0.5)Mn_(0.5)O_2 as cathode materials for Li-ion batteries

通过溶胶-凝胶法在LiNi0.5Mn0.5O2表面包覆一层TiO2,采用X射线衍射(XRD),扫描电镜(SEM),恒电流充放电和电化学阻抗谱(EIS)对材料的结构、形貌及电化学性能进行了研究。实验结果表明,经过包覆后,有效地抑制了电解液对正极材料的侵蚀,包覆量为1.0%(质量分数)的放电容量略有提高,循环性能也得到明显改善。因此TiO2包覆是改善LiNi0.5Mn0.5O2材料的电化学性能的有效方法。

TiO2-coated LiNi0.5Mn0.5O2 materials were prepared by sol-gel method. The crystal structures and morphology of the materials were investigated by X-ray diffraction （XRD） and scanning electron microscopy （SEM） techniques. The electrochemical properties were investigated by charge-discharge tests and electrochemical impedance spectroscopy （EIS）. The result shows that the coating film of TiO2can reduce the corrosion of cathode materials in the electrolye. The discharge capacity of sample coated with 1.0% （mass fraction） TiO2 is increased slightly; also its cyclic stability is improved greatly, Therefore, the TiO2 coating technique is an effective method to improve the electrochemical properties of LiNi0.5Mn0.5O2 cathode material.