NG was modified by concentrated HNO3 used as oxidant, then coated it with C6H8O7, treated at 700? in a nitrogen gas atmosphere for 18 h. The structure and electrochemical performance of the prepared carbon-coated graphite were characterized by XRD and electrochemical performance testing. The effect of different coating proportions on the performance of charge-discharge performance was investigated. The results demonstrated that the coating modification had no significant effect on the structure of graphite. And compared with natural graphite, the coated graphite showed better electrochemical performance. Moreover, the 2:1 1 modified graphite, its initial discharge capacity is 345.1 mA-h-g-1, and will keep 315 mA-h-g-1 after 10 cycles, the capacity fading was only 7.79%.%将天然石墨(NG)用浓HNO3氧化处理后,在其表面包覆柠檬酸,在惰性气体气氛下700℃处理18h,制得了包覆改性石墨.采用XRD及电化学测试等手段对材料进行了结构表征和性能测试.考察了不同包覆比例对材料充放电性能的影响.XRD 结果表明包覆改性对石墨的结构并没有明显的影响.充放电测试表明,与天然石墨相比,包覆改性石墨具有更好的电化学性能,其中又以石墨与柠檬酸质量比为2∶1时性能最好,其首次放电容量为345.1 mA·h·g-1,经20次循环后容量仍保持在305 mA·h·g-1以上,容量衰减率仅为11.01％.
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