High rate capability of coconut kernel derived carbon as an anode material for lithium-ion batteries

Carbon has been prepared by pyrolysis of grated, milk-extracted coconut kernel at 600 °C under nitrogen atmosphere. The disordered carbon has sheet like morphology. The carbon exhibits a high reversible Li⁺ intercalation capacity in a non-aqueous electrolyte. The initial charge and discharge capacities are 990 and 400 mAh g^-1, thus resulting in an irreversible capacity loss of 590 mAh g^-1. Nevertheless, subsequent discharge capacity is stable over a large number of charge-discharge cycles. The electrodes withstand charge-discharge currents as high as 1257 mA g^-1 and they deliver discharge capacity of 80 mAh g^-1. Diffusion coefficient of Li⁺ obtained from galvanostatic intermittent titration is 6.7 × 10^-12 cm² s^-1. Thus the coconut kernel derived carbon is a suitable anode material for Li-ion batteries.