The preparation of double-void-space SnO2/carbon composite as high-capacity anode materials for lithium-ion batteries

• We designed a new nanostructure: double-void-space SnO2/carbon composite.
• We used modified Stöber method to get satisfied thickness of SiO2 layer.
• The large void space made the materials to have sufficient physical buffer zones.
• The composite displayed satisfied results in performance of capacity and cycle life.

In this work, double-void-space SnO2/carbon composite has been synthesized as high-capacity anode materials for lithium-ion batteries. This novel designed structure, with the internal void space inside SnO2 hollow spheres and the external void space between SnO2 and carbon, can superiorly accommodate the large volume change as a physical buffering layer during the charge/discharge procedure. It is found that the double-void-space SnO2/carbon composite manifest a much higher reversible capacity compared to SnO2 hollow spheres. Due to the formation of the void space, the special composite is able to deliver a reversible Li storage capacity of 408.4 mAh g−1 after 50 cycles. This implies the structural optimization can provide new opportunities to enhance the properties of tin-based materials for high-capacity lithium-ion batteries.