Electrochemical Properties of NaTi2(PO4)3 Anode for Rechargeable Aqueous Sodium-Ion Batteries

The charge/discharge characteristics of NaTi 2 (PO 4 ) 3 as an anode active material for aqueous sodium-ion battery containing 2 M Na 2 SO 4 aqueous electrolyte were examined. Cyclic voltammograms, galvanostatic discharge/charge and XRD data of the material indicated that sodium can be reversibly intercalated into NASICON-type NaTi 2 (PO 4 ) 3 without serious degradation of the host structure. The best reversible capacity at rate of 2.0 mA cm −2 was 93% of the theoretical capacity of 133 mAh g −1 and the plateau voltage was 2.1 V versus Na/Na + .