文摘
Pristine and Cu-doped TiO2–B nanowires are synthesized by the microwave assisted hydrothermal method. The doped oxide exhibits a highly porous structure with a specific surface area of 160.7 m2 g–1. As evidenced by X-ray photoelectron spectroscopy and X-ray energy dispersive spectroscopy, around 2.0 atom % Cu2+ cations are introduced into TiO2–B, which leads to not only a slightly expanded lattice network but also, more importantly, a modified electronic structure. The band gap of TiO2–B is reduced from 2.94 to 2.55 eV, resulting in enhanced electronic conductivity. Cyclic voltammetry and electrochemical impedance spectroscopy reveal improved electrochemical kinetic properties of TiO2–B due to the Cu doping. The doped nanowires show a specific capacity of 186.8 mAh g–1 at the 10 C rate with a capacity retention of 64.3% after 2000 cycles. Remarkably, our material exhibits a specific capacity of 150 mAh g–1 at the 60 C rate, substantiating its superior high rate capability for rechargeable lithium batteries.