Enhanced sodium storage behavior of carbon coated anatase TiO2 hollow spheres

Abstract

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.