Alkaline hydrolysis assisted preparation of N/S co-doped anatase TiO2 for high-performance lithium storage

This work reports the preparation of N/S co-doped titanium dioxide (N/S-TiO 2 ) via in-situ sulfur doping assisted by alkaline hydrolysis followed by subsequent nitrogen doping and the lithium storage application. TiCl 4 is used as the titanium source, and sodium sulfide (Na 2 S) solution provides the alkaline hydrolysis environment and sulfur source, thus enabling the synthesis of S doped anatase TiO 2 (S-TiO 2 ). Urea is applied as the nitrogen source under high-temperature annealing, resulting in N/S co-doped anatase TiO 2 (N/S-TiO 2 ) materials. In addition, oxygen vacancies, which might enhance the electronic/ionic conductivity, is created. Consequently, N/S-TiO 2 (10:1) exhibits excellent rate performance (85.6 mAh g − 1 at 20 C) and long-term cycling stability (116.22 mAh g − 1 after 1500 cycles at 3 C). Further analysis using cyclic voltammetry (CV), galvanostatic intermittent titration technique (GITT), and electrochemical impedance spectroscopy (EIS) shows an enhanced pseudocapacitive contribution, increased lithium-ion diffusion coefficient, and reduced charge transfer resistance. These findings provide new insights for developing high-performance, structurally tunable metal oxide anode materials.