Enhanced sodium storage behavior of carbon coated anatase TiO2 hollow spheres

Carbon coated anatase TiO2 hollow spheres (CCAnTHSs) are prepared through the carbon wrapping of etched amorphous TiO2 solid spheres (AmTSSs). The as-obtained CCAnTHS composite is applied as an anode material for sodium-ion batteries (SIBs) for the first time, delivering excellent cycle stability. At a high current density of 5C, a reversible capacity of 140.4 mA h g(-1) remained after 500 cycles. Especially, at a 25C rate it could still reach 84.9 mA h g(-1) after 80 cycles. Briefly, the sodium storage performance of CCAnTHSs are superior to these of the amorphous TiO2 solid spheres and bare anatase TiO2 hollow spheres, mainly benefitting from the advantages of a unique hollow structure with a large specific surface area and a carbon coating with high electronic conductivity.