Effect of doping functionalized MWCNTs on the electrochemical performances of Li2CoSiO4 for lithium-ion batteries

We report the synthesis of Li2CoSiO4 by the sol-gel method and the preparation of a composite electrode by incorporating functionalized multi-walled carbon nanotubes (fn. MWCNTs) as conductive additive. XRD pattern of the composite confirms the structural stability of Li2CoSiO4 even after the addition of fn. MWCNTs. SEM images of the composite reveal the presence of conductive bridges formed by MWCNTs between the submicron-sized particles of Li2CoSiO4. The cyclic voltammograms of the composite cathode show redox peaks with higher current density than pure Li2CoSiO4 and the current density increases with increase in sweep rate. The diffusion coefficient of lithium has been improved by the addition of fn. MWCNTs from 1 x 10(-14) to 8 x 10(-14) cm(2)/s as calculated using Randles-Sevcik equation. The charge-discharge cycling performance of both pure Li2CoSiO4 and composite cathode has been discussed.