Morphology-controlled construction of hierarchical hollow hybrid SnO₂@TiO₂ nanocapsules with outstanding lithium storage

摘要

A novel synthesis containing microwave-assisted HCl etching reaction and precipitating reaction is employed to prepare hierarchical hollow SnO₂@TiO₂ nanocapsules for anode materials of Li-ion batteries. The intrinsic hollow nanostructure can shorten the lengths for both ionic and electronic transport, enlarge the electrode surface areas, and improving accommodation of the anode volume change during Li insertion/extraction cycling. The hybrid multi-elements in this material allow the volume change to take place in a stepwise manner during electrochemical cycling. In particular, the coating of TiO₂ onto SnO₂ can enhance the electronic conductivity of hollow SnO₂ electrode. As a result, the as-prepared SnO₂@TiO₂ nanocapsule electrode exhibits a stably reversible capacity of 770?mA hg?1 at 1?C, and the capacity retention can keep over 96.1% after 200 cycles even at high current rates. This approach may shed light on a new avenue for the fast synthesis of hierarchical hollow nanocapsule functional materials for energy storage, catalyst and other new applications.