Size Dependent Fast Li Ion Storage Based on Size Regulated TiO₂(B) Nanosheet Electrodes with Vertical, Horizontal and Random Alignment

Abstract

TiO₂(B) has a high theoretical capacity of 335 mAh g⁻¹ for Li⁺ intercalation and thus has been considered as a candidate for lithium-ion capacitor and Li-ion battery negative electrodes. For high rate lithium storage, i.e. high power density, it is important to shorten the Li⁺ diffusion path by using nanostructured TiO₂(B). In this work, TiO₂(B) nanosheet with different equivalent diameter of 300 nm and 30 nm were prepared. In addition, the orientation of the TiO₂(B) nanosheets was manipulated by altering the deposition method and drying process. Smaller size TiO₂(B) nanosheets had better Li⁺ intercalation ability compared to larger sized TiO₂(B) nanosheets. The effect of alignment of the TiO₂(B) nanosheets was evident for small-sized TiO₂(B) nanosheets; vertical or random alignment of small-sized TiO₂(B) afforded higher capacity compared to horizontally oriented nanosheets.