Metal-organic framework derived S-doped anatase TiO2@C to store Na+ with high-rate and long-cycle life

The design of a reasonable structure and component regulation are valid methods for enhancing the electrochemical properties of TiO2, which serves as prominent anode in sodium-ion batteries with exceptional structural stability. Herein, the carbon-coated anatase TiO2 doped with S (S-TiO2 @C) was synthesized via a facile metal-organic framework-assisted approach. The S atoms partially substitute oxygen atoms in the lattice, thereby enhancing the capacitive behavior, facilitating charge transfer kinetics, and augmenting the diffusion coefficient of Na+. With exceptionally high porosity and substantial carbon content, the caky S-TiO2 @C electrode manifests superior rate capability of 167.7 mAh g−1 at 5.0 A g−1 and long-cycle life of 239.0 mAh g−1 at 2.0 A g−1 over 4000 cycles. It is foreseeable that the strategy of anionic doping and carbon coating on the metal oxide with porous structure to optimize the sodium storage capability of the electrode will be applied in the future.