Ultrathin TiO2-B nanowires with enhanced electrochemical performance for Li-ion batteries

Abstract

A facile one-step hydrothermal route was designed for preparing ultrathin TiO₂-B nanowires, which were then hybridized with RGO to form a TiO₂-B/RGO hybrid via an in situ approach, and both of them have a large BET surface area (231.6 m² g⁻¹ for TiO₂-B nanowires and 256.1 m² g⁻¹ for the TiO₂-B/RGO hybrid). It was found that the synthesized ultrathin nanowires are perpendicular to the [010] direction which is the most open channel in the TiO₂-B crystal structure, demonstrating more Li-ion insertion/extraction hosts exposed to the electrolyte. Thus, the cell made of TiO₂-B ultrathin nanowires exhibited large reversible lithium-ion charge–discharge capacity, excellent cycling stability and high-rate capability. When combined with RGO, the formed TiO₂-B/RGO hybrid exhibited further improved Li storage performance. For instance, a capacity of 205.3 mA h g⁻¹ was obtained at the fourth cycle and then faded slightly to 189.4 mA h g⁻¹ after 300 cycles, demonstrating a surprising low average capacity fading of ca. 0.026% per cycle from 4th to 300th cycles.