Multi-shelled Hollow Nanospheres of SnO2/Sn@TiO2@C Composite as High-performance Anode for Lithium-Ion Batteries

To overcome two main drawbacks of SnO2 as anode material in lithium-ion batteries, low conductivity and poor cycling stability, SnO2/Sn@TiO2@C composite is prepared via one-pot hydrothermal reaction to synthesize SnO2/C precursor-assembled hollow nanospheres and then coated with TiO2 and resorcinol-formaldehyde resin. After calcination, multi-shelled hollow nanospheres of SnO2/Sn@TiO2@C are formed. When used as anode material in lithium-ion batteries, the as-prepared composite exhibits high discharge capacity of 1565 mAh g(-1) at 0.5 A g(-1). After 300 cycles at 1 A g(-1), the discharge capacity still reaches 961 mAh g(-1) with capacity fading rate of just 0.11 % per cycle. The average discharge capacity reaches 395 mAh g(-1) even at 5 A g(-1). The superior lithium storage performance mainly benefits from the unique multi-shelled hollow nanosphere structure. The coating TiO2 and amorphous carbon increase structural and cycling stabilities of SnO2/Sn hollow nanospheres. The outermost carbon shell further enhances electronic conductivity of the composite. The hollow nanosphere structure also endows SnO2/Sn nanoparticles with high electrochemical activity. This work proposes a feasible synthesis and structure design strategy for the development of advanced SnO2-based composite materials.

Automated summary

The SnO2/Sn@TiO2@C composite prepared via one-pot hydrothermal reaction exhibits high discharge capacity and stability in lithium-ion batteries, attributed to the unique multi-shelled hollow nanosphere structure, coating of TiO2 and carbon layer.