摘要：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。

关键词：石墨烯；二氧化锰；锂离子电池；电化学性能

Abstract：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.

Keywords: graphene；manganese dioxide；lithium-ion batteries；electrochemical properties