石墨烯包覆富锂层状正极材料的电化学性能

Electrochemical Performance of Graphene Coated Li-rich Layered Anode Material

采用固相配位法制得石墨烯包覆的Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_2富锂层状正极材料。用X射线衍射、场发射扫描电镜、循环伏安、恒流充放电和电化学阻抗谱等分析技术对其相组成、微结构和电化学性能进行表征。结果表明:石墨烯包覆Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_2材料的电化学性能显著提高,该材料在电流密度为20 mA/g(0.1C)和1 000 mA/g(5C)时的放电比容量分别为240,132 mAh/g;在电流密度为200 mA/g(1C)时,充放电循环100次后,其比容量保持率为84%。

Grapnene-coated Li-rich layered anode material Li1.2Mn0.54Ni0.13Co0.13O2 was prepared based on a solidstate coordination method. Analytical techniques of X-ray diffraction, field-emission scanning electron microscopy,cyclic voltammetry, galvanostatic charge-discharge measurements and electrochemical impedance spectrometry（EIS） were employed to characterize its phase compositions, microstructure and electrochemical performance.The results show that its electrochemical performance is remarkably improved, compared with that of the pristine Li1.2Mn0.54Ni0.13Co0.13O2. Its discharge capacity is determined to be 240, 132 mAh/g at current density of 200 mA/g（0.1C）, 1 000 mA/g（5C）, respectively. It exhibits a capacity retention of 84% after being cycled for 100 cycles at current density of 200 mA/g（1C）.