Development of novel mesoporous C–TiO 2–SnO 2 nanocomposites and their application to anode materials in lithium ion secondary batteries

Abstract

Herein, we employed the tetra-constituent co-assembly method based on the acid–base pair of Sn and Ti precursors. Using this method, novel mesoporous carbon–TiO 2–SnO 2 nanocomposite materials were prepared and their structural change with an increase of SnO 2 amount was investigated. In low amount of SnO 2, an ordered mesoporous structure was observed but it became collapsed at 64 wt.% SnO 2, while crystal size of anatase TiO 2 embedded within amorphous SnO 2 and carbon matrix became larger. When applied to anode materials in lithium ion batteries, an increase of the reaction peaks of Li + in SnO 2 was observed and peak associated with discharging in TiO 2 nano-crystal increased in spite of lower amount of TiO 2. This indicated that TiO 2 was highly utilized for lithium storage (275 mAh g −1 in 19.9 wt.% TiO 2 case). In the nanocomposite electrode with 28.8% TiO 2, however, a high rate performance and a very stable cycle performance (95.3% retention at 40th cycles) were observed, which was attributed to the stable nanostructure.