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

Abstract

Pure camphor pyrolysed at 900 degrees C fur 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 mu A 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. (C) 2000 Elsevier Science S.A. .