3D CNT decorated Na3V2(PO4)3/C microsphere with outstanding sodium storage performance for Na-ion batteries

To solve the bad conductivity of Na3V2(PO4)3 material for rechargeable Na-ion batteries cathode, carbon layer and carbon nanotubes (CNT) are employed to improve the bad Na-storage performance of Na3V2(PO4)3 cathode. Herein, the Na3V2(PO4)3/C-CNT (Na@C-CNT) composite with a 3D structure has been fabricated via the spray drying technology and heat treatment process. Benefiting from the conductive 3D framework, the Na@C-CNT microsphere exhibits outstanding Na-storage properties in terms of good rate performance and cycling stability. It delivers a high reversible capacity of 111.7 mAh g−1 at 0.1 °C. Even at 10 °C, this electrode can still show a reversible capacity of 89.7 mAh g−1 with the capacity retention of 96.5% over 200 cycles. These excellent electrochemical performances demonstrate promising application of the as-prepared Na@C-CNT microsphere for Na-ion batteries.