Carbon-coated NaTi2(PO4)3 composite: A promising anode material for sodium-ion batteries with superior Na-storage performance

NASICON-type NaTi 2 (PO 4 ) 3 material has been extensively studied as a promising anode for sodium-ion batteries due to the open 3D framework with the large interstitial spaces, high theoretical capacity and small volume change during cycling process. However, the practical application of NaTi 2 (PO 4 ) 3 is hampered because of its low electronic conductivity . Herein, a simple approach along with post-annealing has been designed and adopted to prepare the carbon-coated NaTi 2 (PO 4 ) 3 (NaTi 2 (PO 4 ) 3 @C) composite. The as-prepared anode material is characterized by XRD , SEM, TEM and Raman spectrum . The electrochemical measurements reveal that NaTi 2 (PO 4 ) 3 @C has excellent Na-storage performances including high reversible capacity (112.6   mAh   g −   1 at 0.2   C) and good rate capability (87.1   mAh   g −   1 at 5   C). The superior electrochemical performance can be resulted from the synergistic effects of the nanosized NaTi 2 (PO 4 ) 3 particles and conductive carbon layer .