Structural evolution and electrochemical performance of Li 2 MnSiO 4 /C nanocomposite as cathode material for li-ion batteries

High capacity Li2MnSiO4/C nanocomposite with good rate performance was prepared via a facile sol-gel method using ascorbic acid as carbon source. It had a uniform distribution on particle size of approximately 20nm and a thin outlayer of carbon. The galvanostatic charge-discharge measurement showed that the Li2MnSiO4/C electrode could deliver an initial discharge capacity of 257.1m Ah g-1 (corresponding to 1.56 Li+) at a current density of 10m Ag-1 at 30°C, while the Li2MnSiO4 electrode possessed a low capacity of 25.6m Ah g-1. Structural amorphization resulting from excessive extraction of Li+ during the first charge was the main reason for the drastic capacity fading. Controlling extraction of Li+ could inhibit the amorphization of Li2MnSiO4/C during the delithiation, contributing to a reversible structural change and good cycling performance.