The high capacity and excellent rate capability of Ti-doped Li2MnSiO4 as a cathode material for Li-ion batteries

Abstract

Ti-doped Li₂Mn_1−xTi_xSiO₄ as cathode materials for Li-ion batteries was successfully synthesized by a facile sol–gel method. The addition of Ti to the precursors changed the particle sizes and specific surface areas of Li₂MnSiO₄. The galvanostatic charge–discharge measurements showed that Ti-doped Li₂Mn_1−xTi_xSiO₄ (x = 0.06, 0.1, 0.2) electrodes delivered high charge capacity of 298, 286, 248 mA h g⁻¹ and discharge capacity of 203, 211, 171 mA h g⁻¹ in the first cycle, much higher than that of undoped Li₂MnSiO₄ (52 mA h g⁻¹ for charging and 26 mA h g⁻¹ for discharging). Moreover, the Ti-doped samples exhibited good cycling stability and superior rate capability, as compared to that of pristine sample. Even at a high rate (2 C), the Ti-doped Li₂Mn_1−xTi_xSiO₄ still maintained high discharge capacities. The remarkable enhancement of battery performance in terms of capacity and rate capability for doped Li₂Mn_1−xTi_xSiO₄ was primarily attributed to the decrease of charge transfer resistance and the improvement of the Li⁺ diffusion coefficient.