Engineering\nHigh-Performance SiO_<i>x</i> Anode Materials\nwith a Titanium Oxynitride Coating for Lithium-Ion\nBatteries

Abstract

Micron-sized\nsilicon oxide (SiO_<i>x</i>) has\nbeen regarded as a promising anode material for new-generation lithium-ion\nbatteries due to its high capacity and low cost. However, the distinct\nvolume expansion during the repeated (de)­lithiation process and poor\nconductivity can lead to structural collapse of the electrode and\ncapacity fading. In this study, SiO_<i>x</i> anode\nmaterials coated with TiO_0.6N_0.4 layers are\nfabricated by a facile solvothermal and thermal reduction technique.\nThe TiO_0.6N_0.4 layers are homogeneously dispersed\non SiO_<i>x</i> particles and form an intimate\ncontact. The TiO_0.6N_0.4 layers can enhance the\nconductivity and suppress volume expansion of the SiO_<i>x</i> anode, which facilitate ion/electron transport and\nmaintain the integrity of the overall electrode structure. The as-prepared\nSiO_<i>x</i>-TiON-200 composites demonstrate a\nhigh reversible capacity of 854 mAh g^–1 at 0.5 A\ng^–1 with a mass loading of 2.0 mg cm^–2 after 250 cycles. This surface modification technique could be extended\nto other anodes with low conductivity and large volume expansion for\nlithium-ion batteries.