锂离子电池正极材料LiNi0.8M0.2O2的制备

在增加氧气压力的条件下，采用固相反应制得一系列掺杂不同元素M的锂离子电池正极材料LiNi0.8M0.2O2. 研究发现，掺杂Al, Mn, Ti可以改善材料的耐过充性和循环性能，在充电电压为4.2~4.8 V的范围内循环3次，材料的放电容量没有显著的改变. X射线衍射和扫描电镜分析表明，掺杂Al, Mn, Ti提高了镍酸锂材料的六方菱型结构的有序性，维持了在充放电过程中的层状结构的稳定性. 其它掺杂元素降低了材料结构的有序性，影响了其电化学性能. 说明形成完整的晶体结构是掺杂元素的选择依据.

Preparation and Characterization of LiNi0.8M0.2O2 with Various Doping Elements for Lithium Battery Cathod

With doping different elements (M), a series of compounds LiNi0.8M0.2O2 used as cathode materials in lithium ion batteries were prepared by solid reaction under increased oxygen pressure. It was found that the doped Al, Mn and Ti can improve the properties in overcharge tolerance and cyclic capacity. The discharge capacity was almost kept constant after three cycles at high charging voltage ranging from 4.2 to 4.8 V. XRD and SEM analyses revealed that doping Al, Mn and Ti increased the orderness of the LiNiO2 material in the hexagonal phase and maintained the layered structure during the charging/discharging process. However, doping other elements decreased the orderness of the material structure, which clearly affected the electrochemical properties of the materials.