Abstract

High-power, long-life carbon-coated TiO2 microsphere electrodes were synthesized by a hydrothermal method for sodium ion batteries, and the electrochemical properties were evaluated as a function of carbon content. The carbon coating, introduced by sucrose addition, had an effect of suppressing the growth of the TiO2 primary crystallites during calcination. The carbon coated TiO2 (sucrose 20 wt % coated) electrode exhibited excellent cycle retention during 50 cycles (100%) and superior rate capability up to a 30 C rate at room temperature. This cell delivered a high discharge capacity of 155 mAh gcomposite–1 at 0.1 C, 149 mAh gcomposite–1 at 1 C, and 82.7 mAh gcomposite–1 at a 10 C rate, respectively.