Abstract: Li_1+xCo_0.2Ni_0.8O₂ samples were synthesized by simultaneous precipitation and solution impregnation methods, characterized by X-ray Diffraction (XRD), Scanning Electronic Microscope (SEM), Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) and galvanostatic cycling. The results show that the spherical product, without impurities, has a typical α-NaFeO₂ layered structure and moderate particle size. It is also shown that the product with x=0.08 boasts high efficiency, high specific capacity and good cycling performance with the initial capacity of 183mAh/g and the capacity retention of 93.4% after 50 cycles (2.00mA/cm²).

Key words: lithium ion secondary batteries, cathode materials, Li_1+xCo_0.2Ni_0.8O₂, solution-impregnation method

摘要： 采用共同沉淀和溶液浸渍相结合的方法合成了锂离子二次电池正极材料Li_1+xCo_0.2Ni_0.8O₂(0≤x≤0.10)。用粉末X射线衍射(XRD)、扫描电子显微镜(SEM)、电感耦合等离子体-原子发射光谱(ICP-AES)、电化学等方法对生成物进行了元素组成、形貌、物相与结构、充放电循环等分析。分析结果表明所得到的生成物为球形颗粒，粒径大小均匀，其结构为αNaFeO₂型的层状结构, 生成物中无杂质相, 生成物的首次充放电效率高、比容量高、循环性能好。在2.00mA/cm²电流密度下，首次放电容量可达183mAh/g, 50次循环的保持率为3.4%。

关键词: 锂离子二次电池, 正极材料, Li_1+xCo_0.2Ni_0.8O₂, 溶液浸渍法