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.

Key words: graphite nanosheets; anode material; lithium-ion battery; pencil core