Designed synthesis of coaxial SnO₂@carbon hollow nanospheres for highly reversible lithium storage

A new type of functional nanoarchitecture, coaxial SnO₂@carbon hollow nanospheres, was designed for highly reversible lithium storage. This structure incorporates simultaneously two desirable design rationales for high energy anode materials based on Li-metal alloying, hollow interior space, and carbon nanopainting. Coating of SnO double shells on silica nanospheres was achieved, and the glucose-derived carbon material was coated on SiO ₂@SnO₂ by a simple hydrothermal process. 0.3 g of as-prepared core/shell SiO₂@SnO₂ nanospheres was dispersed by ultrasonication in an aqueous glucose solution. The suspension was transferred to a 40 mLTeflon-lined autoclave, which was then heated in an air flow electric oven at 180°C for 3 h. The electrochemical measurements were carried out with lithium metal as the counter and reference electrodes at room temperature. These coaxial carbon hollow spheres indeed exhibit exceptional cycle life for at least several hundred cycles and rate capability.