Abstract:

We report on the in-situ preparation of Na₂Ti₃O₇ nanosheets and their application as high-performance 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^–1 after 3000 cycles (capacity retention of 96.5%). The superior electrochemical performance of Na₂Ti₃O₇ nanosheets results from the short ion/electron diffusion pathway of the two-dimensional 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.

Key words: Na₂Ti₃O₇, Nanosheet, Binder-free, Anode material, Sodium ion battery