高容量富锂层状材料Li_2MnO_3·2LiNi_(0.5)Mn_(0.5)O_2的制备与表征

Fabrication and characterization of lithium-rich layered cathode material Li_2MnO_3·2LiNi_(0.5)Mn_(0.5)O_2 with high capacity

通过共沉淀法制备了富锂层状正极材料Li2Mn O3·2 Li Ni0.5Mn0.5O2,采用扫描电子显微镜(SEM)、X射线衍射分析(XRD)、循环伏安和恒流充放电测试对其结构和电化学性能进行了表征。研究结果表明富锂正极材料Li2Mn03·2 Li Ni0.5Mn0.5O2具有相对高的比容量及良好的循环性能,首次放电比容量为187.2 m Ah/g,首次充放电库仑效率为74.3%,第二次充放电库仑效率升至97.6%。经过30次循环,放电比容量仍有156.8 m Ah/g,容量保持率为83.7%。

The lithium-rich layered cathode material Li2MnO3·2 LiNi0.5Mn0.5O2 was fabricated by co-precipitation method. The structure and electrochemical properties of the material were examined using scanning electron microscopy （SEM）, X-ray diffraction （XRD）, cyclic voltammetry and galvanostatic charging and discharging test. The results show that the material has high capacity and good cycle performance. The first discharge special capacity is 187.2 mAh/g;the first and second cycle coulombic efficiency are respectively 74.3%and 97.6%. After 30 cycles, the discharge special capacity stil remains 156.8 mAh/g, which is 83.7%of that of the first cycle.