Nanoconic TiO2 hollow spheres: novel buffers architectured for high-capacity anode materials

Abstract

An attempt has been carried out here to use nanoconic TiO₂ hollow spheres as buffers to accommodate the volume expansion of high-capacity materials. Based on the TiO₂ hollow spheres, we tailor-designed a novel composite, in which the high Li⁺-transport dynamics of titanate hollow spheres (TiO₂) and the high capacity of tin oxide (SnO₂) were intimately integrated into a hierarchical architecture of nanocones, while the unique spatial arrangement of the SnO₂ component in the nano-cavities effectively accommodates the volume change during lithiation/de-lithiation, hence rendering the composite stable cycling life. Electrochemical tests revealed favorable performances of the composite SnO₂–TiO₂ nanocones in terms of enhanced lithium storage capacity, stable cycle life and improved rate performance compared with each material components.