锂离子电池正极材料LiMnO2的掺杂及其电化学性能

采用水热法合成了用于锂离子电池正极材料的LiMxMn1-xO2(M=Mg, Y, Zr)化合物. 采用X射线衍射(XRD)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)等手段对材料的晶体结构和形貌进行了表征, 材料的电化学性能通过恒流充放电和交流阻抗谱(EIS)进行测试, 分析了掺杂元素在改善材料性能中的作用. 结果表明, 掺杂后的LiMxMn1-xO2正极材料循环性能优于未经掺杂的材料. 其中以掺杂钇的i0.99Mn0.979Y0.021O2正极材料循环性能最佳, 在室温下, 充放电电流密度为50 mA·g-1时, 60次循环后放电容量为226.3 mAh·g-1.

Doping of Layered LiMnO2 as Cathode Materials for Lithium-Ion Batteries and Their Electrochemical Properties

Hydrothermal methods were used to prepare doped LiMxMn1-xO2(M=Mg, Y, Zr) as cathode materials for lithium-ion batteries. The structure and morphology of the as-prepared cathode materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The effects of ion doping on the performance of orthorhombic materials was analyzed in terms of their crystal structure, charge-discharge curves, cycle performance and electrochemical impedance spectroscopy (EIS). Results show that the doped materials had better cycle performance. In particular, the discharge capacity of Li0.99Mn0.979Y0.021O2 remains 226.3 mAh·g-1 after 60 cycles with a current density of 50 mA·g-1 at roomtemperature.