Crystalline carbon hollow spheres, crystalline carbon-SnO2 hollow spheres, and crystalline SnO2 hollow spheres:: Synthesis and performance in reversible Li-ion storage

A few types of crystalline hollow structures, crystalline carbon hollow spheres (750 nm), crystalline carbon hollow spheres with encapsulated or decorated 1-3 nm SnO2 nanoparticles, and crystalline SnO2 hollow spheres (200-300 nm) synthesized by various methods, have been evaluated for reversible Li+ storage. The experimental results showed noticeable improvements in a number of performance areas such as specific capacity, rate capability, and cyclability. The improvements could be attributed to a high degree of crystallinity, which increases the electronic conductivity, and the facile transport of Li ions in a hollow shell with nanoscale thickness, which significantly shortens the solid-state diffusion length.