RESUMEN
In this study, V5+ doped sodium titanate nanorods were successfully synthesized by a sol-gel method with different optimized vanadium concentrations. Before testing as a promising anode material for sodium ion battery (SIB) application, the samples were systematically characterized. It was clearly observed that V5+ doping significantly affects the phase formation of sodium titanate samples and leads to the alteration of the major phase of Na2Ti3O7 to a single Na2Ti6O13 phase with increasing doping concentrations. Electrochemical investigations clearly showed that the optimized 15 wt% V5+ doped sample exhibits the highest capacity of 136 mA h g-1 at 100 mA g-1 after 900 cycles as well as better rate capability than the undoped sample by delivering 101 mA h g-1 capacity at a high current density of 1000 mA g-1. It is believed that the incorporation of highly charged V5+ in sodium titanate produces oxygen vacancies along with partial reduction of Ti4+ to Ti3+, resulting in improved electronic conductivity. The utilization of oxygen vacancies also preserves the integrity of the electrode, giving rise to long term cycling. Thereby, V5+ doping was found to be an effective strategy to enhance the electrochemical performance of the sodium titanate anode for SIBs.