【摘要】 掺杂改性和表面修饰的LiNi0 8Co0 2O2是锂电池正极换代候选材料.采用共沉淀法制备了系列LiNi0 8-xZnxCo0 2O2材料,并对其进行X射线衍射(XRD)、扫描电镜(SEM)、循环伏安(CV)、电化学阻抗(EIS)和充放电循环性能(CP)测试分析.恒流循环(0 2C、3 0～4 2V)测试结果显示,Zn的掺入使材料的初始放电比容量有大幅增加,循环性能有所改善.其中LiNi0 78Zn0 02Co0 2O2的首次放电比容量达到206 37mAh·g-1.第30循环时,放电比容量仍为204 03mAh·g-1,不可逆容量损失仅为2 34mAh·g-1,显示了很好的初期循环性能.更多还原

【Abstract】 Doping-modified and surface-coating LiNi_0.8Co_0.2O₂ is a new promising candidate cathode matetials for lithium secondary batteries. A series of LiNi_0.8-xZn_xCo_0.2O₂ cathode materials were synthesized by using a liquid phase coprecipitation method. The products were characterized by X-ray diffraction （XRD）, scanning electronic microscopy （SEM）, cycling voltammetry （CV）,electrochemical impedance spectroscopy （EIS） and galvanostatic cycle（0.2C、3.0～4.2 V）. As the results, the electrochemical properties of the materials were improved a lot by Zn-doped. The first discharge specific capacity of LiNi_0.78Zn_0.02Co_0.2O₂ was up to 206.37 mAh·g^-1, The discharge specific capacity could still retain 204.03 mAh·g^-1 after 30 cycles and the irreversible loss of the specific capacity only was 2.34 mAh·g^-1, which revealed that the material had good initial stage cycling property.更多还原