Co‐doping Nitrogen/Sulfur through a Solid‐State Reaction to Enhance the Electrochemical Performance of Anatase TiO2 Nanoparticles as a Sodium‐Ion Battery Anode

Abstract

AbstractNitrogen‐ and/or sulfur‐doping has been used to enhance the electrochemical performance of TiO2 anodes in lithium‐ion batteries. Multiple doping in one step presents a challenge to produce anodes with excellent performance. Herein, we reports a facile process to co‐dope nitrogen and sulfur into black anatase TiO2 nanoparticles accomplished by using a solid‐state reaction with dried TiO2 gel and thiourea. Co‐doping introduced N and S atoms into the TiO2 matrix, increasing oxygen vacancies, thus enhancing the intrinsic electronic conductivity. Co‐doping also decreased the size of TiO2 nanoparticles from 15.6 to 10.1 nm, and increased the surface area from 77 to 129 m2 g−1, facilitating insertion/extraction of Na ions during charge‐discharge cycling. N/S co‐doped TiO2 exhibited a signficantly higher performance as a sodium‐ion battery anode than pristine black TiO2. The rate performance of the co‐doped TiO2 is improved up to 80 % in comparison with pristine black TiO2.