Manipulating Oxidation of Silicon with Fresh Surface Enabling Stable Battery Anode.

ABSTRACT

Silicon (Si)-based material is a promising anode material for next-generation lithium-ion batteries (LIBs). Herein, we report the fabrication of a silicon oxide-carbon (SiOx/C) nanocomposite through the reaction between silicon particles with fresh surface and H2O in a mild hydrothermal condition, as well as conducting carbon coating synchronously. We found that controllable oxidation could be realized for Si particles to produce uniform SiOx after the removal of the native passivation layer. The uniform oxidation and conductive coating offered the as-fabricated SiOx/C composite good stability at both particle and electrode level over electrochemical cycling. The as-fabricated SiOx/C composite delivered a high reversible capacity of 1133 mAh g-1 at 0.5 A g-1 with 89.1% capacity retention after 200 cycles. With 15 wt % SiOx/C composite, graphite-SiOx/C hybrid electrode displayed a high reversible specific capacity of 496 mAh g-1 and stable electrochemical cycling with a capacity retention of 90.1% for 100 cycles.