Study of camphor-pyrolysed carbon electrode in a lithium rechargeable cell

Pure camphor pyrolysed at 900°C for 2 h in different gaseous environments yields graphite-like carbons which were used as a negative electrode in rechargeable carbon/Li cells. These cells were continuously cycled at a constant current of 300 μA cm−2 for 10–20 days and reversible Li+ intercalation capacities of 0.45–0.61 were observed. Kinetic analysis of such a cell was studied by complex impedance spectroscopy and current interruption. After initial irreversible passivation during the first discharge, fully reversible intercalation capacity was observed for subsequent charge–discharge cycles. This property makes the camphor-pyrolysed carbon (CPC) a promising electrode material for further investigation for making a rechargeable lithium battery. A CPC/Li cell model is proposed. The structural properties of the camphor-pyrolysed electrode material is discussed on the basis of SEM, TEM, XRD and FTIR analyses.