A Ru-Doped VTi2.6O7.2 Anode with High Conductivity for Enhanced Sodium Storage

Abstract

Sodium-ion batteries (SIBs) are considered a potential replacement for lithium-ion batteries in the area of low-cost large-scale energy storage. Due to its low operating voltage, high capacity, non-toxicity and low production cost, titanium dioxide is now among the anode materials under investigation and shows the most promise. However, its poor electrical conductivity is one of the main reasons limiting its large-scale application. Herein, we designed a ruthenium-doped anatase-type VTi2.6O7.2 ultrafine nanocrystal (Ru-VTO). As the anode of SIBs, Ru-VTO delivers a high specific capacity of 297 mAh g−1 at 50 mA g−1, a long cycle life of 2000 cycles and a high rate capability (104 mAh g−1 at 1000 mA g−1). The excellent performance may be related to the solid-solution interatomic interactions and the enhanced conductivity after ruthenium doping. These studies demonstrate the potential of Ru-VTO as an anode material for advanced SIBs.