O-Vacancy and PANI Dual Modifying Titanium Dioxide for Fast Sodium Storage

Abstract

TiO2 is a promising anode material for sodium ion (Na+) storage owing to its structural stability, high safety and abundant resource availability. However, its poor conductivity hinders further practical application. Herein, we design an O-vacancy and polyaniline (PANI) dual-modified TiO2 anode (TiO2-OV@PANI) to enhance its performance for Na+ storage. The O-vacancy in TiO2 modulates the electronic structure, favourable for absorbing more Na+ and enhancing the reaction kinetics. The protonated PANI modification maintains the structural stability of the anode material and further increases the electron transfer to improve the reaction kinetics. As a result, the as-prepared TiO2-OV@PANI demonstrates stable cycling ability with the high discharge capacity of 175 mA h g-1 after 160 cycles at 1 A g-1 and high rate performance (144 mA h g−1 at 2.5 A g−1). Our strategy here provides a good reference on adapting the O-vacancy and PANI dual modification to enhance the performance of the TiO2 anode for Na+ storage.