层状锰酸锂正极材料的掺杂改性及性能

Synthesis and characterization of doping cathode material layered lithium manganese oxides

采用溶胶-凝胶法制备层状LiMnO2的正极材料，并对其进行不同比例的过渡元素钴镍镧铈掺杂改性。用XRD以及SEM对其进行物相和表面形貌的分析，同时用锂离子电池模具装配电池以及进行恒电流充放电、循环伏安等电化学测试，分析了掺杂元素对其电化学性能的影响。XRD分析结果表明所合成的锰酸锂材料呈斜方晶系，SEM形貌显示产物为明显的层状结构，循环充放电测试结果表明掺杂2％Ni2％Co6％Ce的层状锰酸锂正极材料的初次放电比容量为161．8mAh／g，循环稳定性较好：而掺杂了6％Co4％La的层状锰酸锂正极材料的初次放电容量为111．5mAh／g，表现了很好的电化学性能。

Layered LiMnO2 as the cathode material for lithium ion battery, was prepared by sol-gel method. Various concentrations of cobalt, nickel, lanthanum and cerium were doped. Some models of lithium secondary batteries were used in order to convenience the experiment. The characterization and properties are obtained by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and electrochemical galvanostatic charge-discharge cycling. XRD results reveal that basic structure of the sample is orthorhombic LiMnO2 with a high purity. SEM images show that all the LiMnO2 samples with La doping are well-ordered layered structure The electrochemical galvanostatic charge-discharge cycling behavior shows that the discharge capacity of the LiMnO2 with 2%Ni2%Co6%Ce doping is 161.SmAh/g. The capacities of 6%Co4%La doping is 111.5 mAh/g. The specific capacity and cycle performance are all improved.