Constructing the Single-Phase Nanotubes with Uniform Dispersion of SiOx and Carbon as Stable Anodes for Lithium-Ion Batteries.

SiOx is an attractive anode material for lithium-ion batteries due to its considerable capacity. However, its obvious volume expansion and low conductivity result in poor electrochemical performance. Herein, a novel single-phase nanotube structure with uniform distribution of nanoscale SiOx units and amorphous carbon matrix was fabricated. The hollow nanotube and homogeneously distributed ultrafine SiOx units greatly alleviate volume changes. The amorphous carbon facilitates electron transport throughout the network and offers a buffer to further reduce the volume expansion of SiOx. Benefiting from this unique structure, as-prepared single-phase SiOx/C NTs demonstrate excellent durability and rate capability. Specifically, it delivers a high reversible specific capacity (713 mAh g at 0.1 A g after 200 cycles); negligible capacity decay is confirmed after 500 cycles at high density current (544 mAh g at 1 A g after 500 cycles).