将共沉淀法制得的碳酸盐前躯体 Mn_0.75 Ni_0.25CO₃与 Li₂ CO₃以及不同量的纳米TiO₂ 均匀混合，并在 900 ℃ 下烧结 10 h 得到 Li[Li_0.2 Ni_0.2 Mn_0.6-X Ti_X]O₂( x = 0. 00，0． 01，0． 02，0． 05，0． 10) 正极材料，ICP( 感应耦合等离子体) 分析表明制备的材料组分基本符合最初的设计． 通过 X 射线衍射( XRD) 和扫描电子显微镜( SEM) 表征发现，掺杂量达到一定程度时会改变基体材料的结构并对微观颗粒起到分散作用． 电化学测试结果表明: Ti掺杂量为 0． 02 的材料具有最佳的电化学性能: 0． 1C 倍率下循环 30 次时量没有任何衰减; 其在各倍率下的放电比容量较未掺杂材料均有 7 ～13mAh/g 的提升;0． 1C 倍率下 30 次循环的中值电压衰减为 0． 08mV． EIS( 电化学阻抗谱) 测试结果表明 Ti 掺杂量为 0． 02 的材料性能的提高可能来自于 Ti 掺杂对材料结构稳定性的改善．

The Li[Li_0.2 Ni_0.2 Mn_0.6-X Ti_X]O₂(x =0. 00，0. 01,0. 02,0. 05 and 0. 10) cathode materials were pre- pared by uniformly mixing the carbonate precursor Mn_0.75 Ni_0.25CO₃ obtained by means of the co-precipitation meth- od,Li₂ CO₃ and different amounts of nano-TiO₂ and then sintering them under 900℃ for 10h.The ICP (Inductively Coupled Plasma) analysis indicates that the components of the prepared materials accord well with the initial de- sign.By means of XRD and SEM,it is found that,when the doping amount of Ti 4 + reaches up to a certain degree,the structure of the pristine material is changed and the micro particles are refined.The results of electrochemical tests show that,when the doping amount of Ti is 0. 02,the doped material exhibits an optimal electrochemical per- formance: specifically,the capacity still keeps constant and the mean voltage fading decreases to 0. 08 mV after 30 cycles at 0. 1C rate.In addition,the discharge capacities of the doped material at various rates increase by 7 ～ 13mAh/g in comparison with that of the material before the doping． EIS (Electrochemical Impedance Spectroscopy) tests demonstrate that the electrochemical performance improvement of the Li[Li_0.2 Ni_0.2 Mn_0.58 Ti_0.02 ]O₂ may be at- tributed to the improvement of the material structure stability by means of the Ti doping.