二氧化锰—石墨烯复合电极材料的制备与表征

Preparation and characterization of manganese dioxide-graphene composite electrode materials

利用水热法制备MnO2和MnO2-石墨烯（GNs）复合材料,并分别作为锂离子电池的负极材料,进行XRD、SEM、恒电流充放电（GC）、循环伏安（CV）和交流阻抗（EIS）等测试。结果表明,制备的MnO2为β-MnO2,长度为1～2μm,宽度小于200 nm的纳米棒。β-MnO2-GNs复合材料在0.1 C的电流密度下循环60次的放电比容量为659.8 m A·h/g,放电容量保持率为46.4%,在5C电流密度下,放电比容量保持在418 m A·h/g。

MnO2 and MnO2-Graphene composites as anode material for lithium-ion batteries were synthesized by a conventional hydrothermal route. The samples were investigated by X-ray diffraction, scanning electron microscopy, galvanostatic charge-discharge, cyclic voltammetry and AC impedance methods. The present results indicated that the synthesized MnO2 is β-MnO2, which is a length of 1 ~2 μm, and the diameter of the nanorods within 200 nm. The β-MnO2-GNs composites present a good discharge specific capacity of 659.8 m A·h/g at a current density of 0.1 C after 60 cycles,the retention rate of discharge capacity is 46.4% and have a excellent rate capability of418 m A·h/g at a current density of 5 C.