Solvothermal synthesis of Na2Ti3O7 nanowires embedded in 3D graphene networks as an anode for high-performance sodium-ion batteries

Abstract

Sodium titanate (Na2Ti3O7) has been extensively investigated as a promising anode material for sodium ion batteries (SIBs), while the poor cycling stability caused by its low electrical conductivity hinders its practical applications. Herein, Na2Ti3O7 nanowires embedded into three-dimensional (3D) reduced graphene oxide to form a porous hybrid composite (Na2Ti3O7/rGO) has been successfully synthesized via a facile solvothermal method. As an anode for SIB, this composite exhibits significantly enhanced electrochemical performances due to the porous interconnected conductive network with uniformly embedded Na2Ti3O7 nanowires, which is beneficial for the increase of contact area between the electrolyte and active material, and also provides an ideal conductive matrix for fast electron/ion transportation. Therefore, the composite delivers a reversible capacity of ∼134mAh/g after 300 cycles at 100mA/g, and a good rate capacity of 116mAh/g even at a high current density of 2000mA/g, among the best results of the reported Na2Ti3O7-based materials, demonstrating its potential SIB applications.