High performance Li2MnSiO4 prepared in molten KCl–NaCl for rechargeable lithium ion batteries

Abstract

Li2MnSiO4/C composites have been prepared by a facile molten salt method followed by a carbon coating process. Submicron Li2MnSiO4 particles are obtained in KCl–NaCl molten phase with a short reaction time of 3h. The orthorhombic structure and sphere-like morphology are confirmed by X-ray diffraction and scanning electron microscope. Ex-situ XRD study confirms amorphous transition of Li2MnSiO4 during the first charge process. Galvanostatic charge-discharge tests display high initial charge and discharge capacities of 265 and 194 mAh g−1, respectively, at 0.05C rate for the Li2MnSiO4/C composite prepared at 700°C. At 0.1C rate, it maintains a discharge capacity of 165 mAh g−1 and its capacity retention at the 50th cycle is up to 78%, showing superior cycling stability.