Facile synthesis of yolk–shell structured SiO_x/C@Void@C nanospheres as anode for lithium-ion batteries

Silicon oxide (SiO_x) is an attractive anode material for lithium-ion battery due to its high specific capacity and low working potential. However, its scale utilization confronts with low electrical conductivity and large volume expansion. Herein, a yolk-shell structured N, S co-doped SiO_x/C@void@C nanosphere is fabricated through a one-pot organosilica template mediated strategy. The co-doping of N, S enables SiO_x/C@void@C with good conductivity, increased lithium storage capacity and improved interfacial contact. The hollow void between SiO_x/C core and carbon shell effectively buffers the large volume change during the cycling. Consequently, the yolk-shell SiO_x/C@void@C structures exhibit excellent electrochemical performance, with a high discharge specific capacity of 879 mAh·g⁻¹ after 100 cycles at 0.1 A·g⁻¹, outstanding rate capability of 464 mAh·g⁻¹ at 5 A·g⁻¹ and excellent cycling stability of 584 mAh·g⁻¹ after 500 cycles at 1.0 A·g⁻¹.