High Rate Capability Of Coconut Kernel Derived Carbon As An Anode Material For Lithium-ion Batteries

¹Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India

²Energy Storage and System Initiative Center, Indian Institute of Science, Bangalore 560012, India

Adv. Mater. Lett., 2014, 5 (4), pp 184-190

DOI: 10.5185/amlett.2013.8530

Publication Date (Web): Feb 16, 2014

Copyright © IAAM-VBRI Press

E-mail: muni@ipc.iisc.ernet.in

Abstract

Carbon has been prepared by pyrolysis of grated, milk-extracted coconut kernel at 600 ºC 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 x 10^-12 cm² s^-1. Thus the coconut kernel derived carbon is a suitable anode material for Li-ion batteries.

Keywords

Coconut kernel carbon, Li-ion cells, charge-discharge cycling, high rate capability.