In order to improve the cycle and rate performance of LiNi0.5Mn1.5O4, LiCr2 Ni0.5 Mn1.5 O （0≤Y≤0.15） particles were Y -Y -Y 4 synthesized by the sucrose-aided combustion method. The effects of Cr doping in LiNi0.5Mn1.5O4 on the structures and electrochemical properties were investigated. The samples were characterized by X-ray diffractometry （XRD）, scanning electron microscopy （SEM）, cyclic voltammetry （CV）, galvanostatic charge-discharge test and electrochemical impedance spectrum （EIS）. The results indicate that the LiCr2 Ni0.5 Mn1.5 O possess a spinel structure and small particle size, and LiCr0.2Ni0.4Mn1.4O4exhibits Y -Y -Y 4 the best cyclic and rate performance. It can deliver discharge capacities of 143 and 104 mA·h/g at 1C and 10C, respectively, with good capacity retention of 96.5% at 1C after 50 cycles.
二氧化钛(TiO_(2))因其储量丰富、环境友好、性能稳定等特点,作为锂离子电池负极被广泛研究。但低的电子电导率阻碍了其实际的应用。本文通过水热法结合热处理工艺制备了磷掺杂的二氧化钛空心微球。其中空心结构提供了大的比表面,同时磷掺杂产生Ti能协同改善TiO_(2)导电性,因此,制得的空心微球其显示出改善的电化学性能。0.2 C电流密度下首次放电比容量为259.2 m Ah/g,5 C电流密度下循环500圈容量保持率达83%。
