High-performance lithium storage of Ti3+-doped anatase TiO2@C composite spheres

Abstract

Ti³⁺-Doped anatase TiO₂@C composite spheres (TD-TiO₂@C) are synthesized for the first time by the solvothermal method, followed by calcination using as-prepared anatase/TiO₂-B hybrid TiO₂ spheres and glycerol solution in alcohol as reactants. TD-TiO₂@C spheres exhibit excellent electrochemical performance as anode materials for lithium ion batteries (LIBs). The electrodes not only exhibit a superior capacity of 244.80 mA h g⁻¹ at 1C (0.168 A g⁻¹) after 100 cycles, but also show an eminent rate capability. TD-TiO₂@C spheres retain discharge capacities of 171.78, 143.45, 119.17, 105.82 mA h g⁻¹ after 500 cycles at 5C, 10C, 20C, 30C, holding a capacity retention as high as 91.0%, 84.2%, 82.1%, 82.0% when compared with discharge capacities at the 10th cycle, respectively. The improved electrochemical properties are mainly due to the synergistic effects of carbon coating and Ti³⁺ doping, which can enhance significantly the inherent electronic conductivity of TiO₂. Therefore, TD-TiO₂@C can be an attractive candidate for anode materials in LIBs, also with great promise.