Structure, Morphology, and Electrochemical Properties of Carbon-Coated Lithium-Manganese Orthosilicate with Sucrose as a Carbon Source

摘要

Lithium-manganese orthosilicate powders were synthesized via a modified solvothermal method. Three different weight ratios of sucrose used as a carbon source were investigated for finding an effective carbon coating process. Synthesized materials were analyzed by structural and morphological (X-ray powder diffraction, scanning electron microscopy, N-2 adsorption/desorption, thermogravimetry analysis) and electrochemical (chronopotentiometry, cyclic voltammetry) methods. By increasing the sucrose content, the electrochemical performance improvement of lithium-manganese orthosilicate powder was observed, such as an increase in its specific capacity (132%) and cyclability (5%) compared with uncoated sample. The enhancement in Li2MnSiO4 performance is related to an increase in its electrical conductivity and enlargement in the electrochemically active surface area due to carbon coating process.