An investigation of Li0.6Na2.4V2(PO4)2F3 cathode with NASICON structure in lithium-ion battery

Li0.6Na2.4V2(PO4)2F3 holding a NASICON structure is synthesized via ion exchange from Na3V2(PO4)2F3. The Na+ ions at Na(2) sites and inserted Li+ ions in this NASICON structure are suggested to give a large initial specific capacity and a hybrid-ion migration during electrochemical cycling. As a lithium-inserted cathode material, Li0.6Na2.4V2(PO4)2F3 exhibits a specific capacity of 123 mAhg−1 at a current density of 0.1C with two plateaus around 3.77 and 4.19 V vs. Li+/Li. The capacity of the Li0.6Na2.4V2(PO4)2F3/Li battery can retain 104 mAhg−1 with a high coulombic efficiency of 98.6% at 0.1C after 151 cycles.