Well-dispersed tin nanoparticles encapsulated in amorphous carbon tubes as high-performance anode for lithium ion batteries

摘要

Tin/carbon (Sn/C) nanocomposite is considered as a promising anode material for high-performance Li-ion batteries (LIBs). However, since the carbon matrix is always derived from high-temperature carbonization of polymers and Sn has a low melting point (232 degrees C), the Sn nanoparticles in the Sn/C tend to be heavily aggregated during the carbonization process. It is thus challenging to synthesize well-dispersed Sn nanoparticles in a carbon matrix. Here, we report a facile templating method to encapsulate uniform well-dispersed Sn nanoparticles in amorphous carbon tube (Sn@aCT). The electrode fabricated with the hierarchical Sn@aCT exhibits excellent cycle performance. A stable specific capacity of 870 mAh g(-1) after 350 cycles and a Li-ion diffusion coefficient as high as 1.2 x 10(-12) cm(2) s(-1) are obtained. Meanwhile, the intermediate structure of SnO2@aCT and a carbon-coated Sn yolk-shell nanostructure (Sn@C-YS) are investigated for comparison. The results further manifest the advantage of the architecture of the Sn@aCT. Our strategy provides a feasible way to optimize Sn/C nanocomposite as a high-performance anode material for LIBs.