NaTi₂(PO₄)₃Nanoparticles Embedded in Carbon Matrix as Long-Lived Anode for Aqueous Lithium Ion Battery

NaTi 2 (PO 4 ) 3 nanoparticles with the average size of 10–20 nm have been embedded in carbon matrix by a novel two-step approach and the composite was employed as an anode for aqueous lithium ion battery (ALIB). An ALIB consisting of a commercial LiMn 2 O 4 cathode, NaTi 2 (PO 4 ) 3 /C anode and Li 2 SO 4 electrolyte has been firstly constructed. The cell delivers an average platform voltage of 1.6 V and excellent rate capability with reversible capacities of 115 mAh g −1 and 83 mAh g −1 (based on the mass of NaTi 2 (PO 4 ) 3 ) at 30 mA g −1 and 1500 mA g −1 , respectively. It is interesting to note that no obvious capacity fading is observed after 300 cycles at 150 mA g −1 . Even after an ultra-long cycling test up to 3600 cycles at 1500 mA g −1 , 95% of the initial capacity is maintained, indicating the superior cycling stability for as-prepared NaTi 2 (PO 4 ) 3 /C composite. The Li ion intercalation/deintercalation mechanism of NaTi 2 (PO 4 ) 3 anode has also been investigated. The outstanding electrochemical performance and low cost enable the NaTi 2 (PO 4 ) 3 /C a very promising anode candidate for ALIBs.