In-situ preparation of Na2Ti3O7 nanosheets as high-performance anodes for sodium ion batteries

Abstract

We report on the in-situ preparation of Na2Ti3O7 nanosheets and their application as highperformance anode material for sodium ion batteries. Nanosheets with interconnected micro-nano architectures are prepared by simply engraving commercial titanium foils. Furthermore, the foils can be used directly as electrodes without redundant conductive additives or binders. The electrode material exhibits excellent electrochemical performance with reversible capacity of 175 mAh g−1 at 50 mA g−1 and 120 mAh g−1 at 2000 mA g−1after 3000 cycles (capacity retention of 96.5%). The superior electrochemical performance of Na2Ti3O7 nanosheets results from the short ion/electron diffusion pathway of the twodimensional architecture and the good conductive capability of the binder-free structure. The anode of the binder-free Na2Ti3O7 nanosheets effectively overcomes poor ion/electron conductivity, the main drawback of Na2Ti3O7 electrodes, and is promising for rechargeable sodium ion batteries.