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

Abstract

NaTi2(PO4)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 LiMn2O4 cathode, NaTi2(PO4)3/C anode and Li2SO4 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 NaTi2(PO4)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 NaTi2(PO4)3/C composite. The Li ion intercalation/deintercalation mechanism of NaTi2(PO4)3 anode has also been investigated. The outstanding electrochemical performance and low cost enable the NaTi2(PO4)3/C a very promising anode candidate for ALIBs.