In situ synthesis of silica/graphite anode material with enhanced lithium storage performance

The cycling stability and rate performance of anode materials should be increased to meet the demands for automotive power batteries with a long-life and fast charging capability. In this study, a silica/graphite anode material was synthesized in situ via a hydrolysis-calcination route using ethyl orthosilicate as the silicon source. The morphology and structure of silica/graphite anode materials were examined by SEM, XRD, and XPS techniques. The electrochemical properties of silica/graphite materials were investigated by galvanostatic charge–discharge, cyclic voltammetry and electrochemical impedance spectroscopy techniques. The results showed that amorphous silica microspheres were embedded in the graphite matrix. This structure not only strengthened the bonding of Si–O–C but also improved the composition of the solid-electrolyte interphase. The specific capacity of the silica/graphite anode material could be stabilized at approximately 450 mAh g−1 after 300 cycles at a current density of 100 mA g−1, resulting in stable lithium storage due to the synergistic effect between the silica and graphite.