Facile Synthesis of Yolk–Shell Structured SiOx/C@Void@C Nanospheres as Anode for Lithium-Ion Batteries

Abstract Silicon oxide (SiOx) 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 SiOx/C@void@C nanosphere is fabricated through a one-pot organosilica template mediated strategy. The co-doping of N, S enables SiOx/C@void@C with good conductivity, increased lithium storage capacity and improved interfacial contact. The hollow void between SiOx/C core and carbon shell effectively buffers the large volume change during the cycling. Consequently, the yolk-shell SiOx/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.