Dense Sandwich-like Na₂Ti₃O₇@rGO Composite with Superior Performance for Sodium Storage

Sodium titanate (Na₂Ti₃O₇) has been considered as a promising anode in sodium-ion batteries (SIBs) because of its low working voltage, high energy density and low cost. However, low electronic and ionic conductivity become the major obstacles to affect the improvement of its electrochemical performance. Here, based on the high specific surface area and high conductivity of reduced graphene oxides (rGO), a dense sandwich-like structure was built through a facile hydrothermal route. The Na₂Ti₃O₇@rGO (NTO@rGO) composites have a stable two-dimensional conductive network framework and the Na₂Ti₃O₇ particles grow in situ on the surface of the rGO nanosheets, greatly improving the utilization of rGO by reducing the introduction of rGO. Moreover, when the NTO@rGO was used as an anode for SIBs, it showed an excellent cycle stability and rate performance with 137 mAh g⁻¹ at 100 mA g⁻¹ after 500 cycles and 92 mA g⁻¹ at 2 A g⁻¹, respectively.