Novel titanium vanadate with superior Na+ transport kinetics for rapid charging and low-temperature sodium ion batteries

Abstract

Sodium-ion batteries (SIBs) hold great promise for large-scale energy storage in the post-lithium-ion battery era due to their high rate performance and long lifespan, although their sluggish Na+ transformation kinetics still require improvement. Encouraged by the excellent electrochemical performance of titanium-based anode materials, here, we present a novel titanium vanadate@carbon (TVO@C) material as anode for SIBs. Our TVO@C material is synthesized via a facile coprecipitation method, with the following annealing process in an acetylene atomosphere. The opened ion channel and the oxygen vacancies within TVO@C facilitate the diffusion of Na+ ions, reducing their diffusion barrier. Thus, an ultrahigh rate of 100 A g−1 and long life of 10,000 cycles have been achieved. Furthermore, the TVO@C electrode exhibits stable performance, not only at room temperature, but also at temperatures as low as −20 °C. The TVO@C||Na3V2(PO4)3@C full cells have also achieved stable discharge/charge for 500 cycles. It is believed that this strategy provides new insight into the development of advanced electrodes and provides a new opportunity for constructing novel high rate electrodes.