Electrochemical properties of nano-sized Li3V2(PO4)3/C composite powders prepared by spray pyrolysis from spray solution with chelating agent

Li3V2(PO4)3/C nanoparticles are prepared by spray pyrolysis. Particles formed from spray solutions containing citric acid and ethylenediaminetetraacetic acid (EDTA) as chelating agents are large and hollow with thin walls. The optimum concentrations of citric acid and EDTA are each 0.1 M. Powders subsequently treated at 700 °C under a reducing atmosphere have particles of single phase, monoclinic Li3V2(PO4)3. The Li3V2(PO4)3/C powders contains 14.9 wt% carbon. The hollow structures are easily pulverized into nanoparticles by simple milling process. However, Li3V2(PO4)3 powder formed from spray solution without chelating agent has larger, aggregated structures. Both powders’ charge curves show four plateaus at ca. 3.62, 3.70, 4.08 and 4.55 V. The initial discharge capacities of the Li3V2(PO4)3/C powders at constant current densities of 0.1, 1 and 3 C were 147, 122 and 86 mAh g−1, respectively. The capacity retention of the Li3V2(PO4)3/C nanoparticles at a high current density of 1 C after 100th cycle was 78%.