【摘要】 以石墨铅笔的笔芯为原料,通过简单涂抹的方法成功制备类似石墨烯纳米片的薄片结构.对该石墨片材料在0.1 C(1 C=372 mA/g)电流密度下进行电化学性能测试,并与铅笔芯直接碾磨制备的石墨材料进行比较,结果发现,石墨纳米片的充放电曲线显著不同,首次可逆比容量为402 mA.h/g,高于石墨材料的比容量和碳的理论比容量.经过20圈循环后,可逆比容量下降为367 mA.h/g,为首次比容量的91.3%.石墨片材料具有较好的循环稳定性和较高的比容量,主要是因为石墨片具有二维片状纳米结构,比表面积很大,锂离子可同时储存在纳米片的正反两面和侧面.更多还原

【Abstract】 Graphite nanosheets have been successfully synthesized by pencil painting on the surface of Cu foil using commercial 6B pencil.Electrochemical properties of the as-prepared graphite nanosheets were tested at a constant current(0.1 C,1 C=372 mA/g),and compared with graphite materials prepared by hand-milling the pencil core.The nanosheets showed different discharging and charging curves and large reversible capacity of 402 mA·h/g in the first cycle,which was larger than the capacity of graphite materials and the theoretical value of carbon.After 20 cycles,charge capacity of 367 mA·h/g was retained,corresponding to 91.3% of the initial charge capacity.The obtained graphite nanosheet is a two-dimensional nanosheet with large surface areas,which can provide more active sites for lithium storage including both sides and the edge parts of the nanosheets.更多还原