Niobium-Doped Titanium Dioxide with High Dopant Contents for Enhanced Lithium-Ion Storage

Abstract

Titanium dioxide is a promising anode for efficient lithium-ion storage in terms of low cost, good structural stability, and inherent safety. However, its performance in Li-ion storage is hindered by poor electronic conductivity. In this work, a solvothermal approach was applied for the synthesis of Nb-doped TiO2 nanocrystals with Nb content up to 33 at. %. The enhanced electronic conductivity and favorable electrochemical kinetics led to superior specific capacity, rate capability, and cycling stability compared to pristine TiO2. For the optimum dopant content of 21 at. %, a specific capacity of 58 mAh g−1 was reached at 10 A g−1 compared to just 28 mAh g−1 for pure TiO2, in addition to almost 20 % higher capacity retention after prolonged cycling. The strategy in the current work can be easily extended to the design of other high-performance electrode materials for energy storage.