中文摘要：

用水热法合成了锂离子电池正极材料正交结构LiMnO2材料，并对其进行S2-、大尺寸阳离子（Cu2＋，Co3＋，Ti4＋）以及硫-金属离子复合掺杂改性．用x射线衍射（XRD）、X光电子能谱分析（XPS）、透射电子显微镜（TEM）、恒电流充放电、交流阻抗谱（EIS）等测试技术进行表征．实验结果表明：当掺入离子的含量较低时，得到的产物能保持完整的正交结构，并表现出较好的电化学性能．S2-和非Jahn-Teller效应大尺寸阳离子的掺入使材料的循环稳定性能大幅度提高，而这种提高是源于这些离子对LiMn02结构的稳定作用．电极材料Li1.02Mno-988Ti0．01201．989S0.011显示了最优的电化学性能，在50mA·g-1放电速率下，其初始放电容量为142．6mAh·g-1，60次循环后放电容量为213．4mAh·g-1．硫-金属阳离子复合掺杂，综合了大尺寸阳离子可以提高材料中Li＋的扩散能力和S2-掺杂抑制Jahn．Teller畸变两方面优势。使层状结构LiMnO2正极材料既保持了较高的容量又获得良好的循环性能．

英文摘要：

Orthorhombic structure LiMnO2 compounds used as cathode materials for lithium-ion batteries were synthesized by a hydrothermal method, and modified by doping with sulphur ion （S2-）, large-sized cation （Cu2＋, Co3＋, Ti4＋） and co-doping with S-M （M=Cu, Co, Ti）. The structure and electrochemical performances of the as-prepared materials were studied by X-ray powder diffraction （XRD）, X-ray photoelectron microscopy （XPS）, transmission electron microscopy （TEM）, chronoamperometry and electrochemical impedance spectroscopy （EIS）. The synthesized materials exhibit a standard orthorhombic structure and good electrochemical performance after the doping with a spot of above-mentioned ions. The beneficial effect of these cations on improving cyclability was demonstrated, due to that the stability of LiMnO2 ortho- rhombic structure is enhanced by the doping with these non-Jahn-Teller ions. The electrode of Li1.02Mn0.988Ti0.012O1.989S0.011 shows excellent electrochemical properties with the first discharge capacity of 142.6 mAhog-1 and retaining 213.4 mAh·g-1 after 60 cycles at a current rate 50 mA·g-1. The electrochemical results reveal that the co-doping of S-M （M=Cu, Co, Ti） combines the advantages of the improvement of Li＋diffusion by cation doping, with the suppression of Jahn-Teller distortion by S2- doping. In the meantime, the co-doped materials also achieve higher capacity and better cyclic performance than the pristine LiMnO2.