Ionic-Liquid-Assisted Synthesis of Nanostructured and Carbon-Coated Li3V2(PO4)3 for High-Power Electrochemical Storage Devices

Carbon-coated Li3V2(PO4)(3) (LVP) displaying nanostructured morphology can be easily prepared by using ionic-liquid-assisted sol-gel synthesis. The selection of highly viscous and thermally stable ionic liquids might promote the formation of nanostructures during the sol-gel synthesis. The presence of these structures shortens the diffusion paths and enlarges the contact area between the active material and the electrolyte; this leads to a significant improvement in lithium-ion diffusion. At the same time, the use of ionic liquids has a positive influence on the coating of the LVP particles, which improves the electronic conductivity of this material; this leads to enhanced charge-transfer properties. At a high current density of 40C, the LVP/N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide material delivered a reversible capacity of approximately 100mA hg(-1), and approximately 99% of the initial capacity value was retained even after 100cycles at 50C. The excellent high rate and cycling stability performance make Li3V2(PO4)(3) prepared by ionic-liquid-assisted sol-gel synthesis a very promising cathode material for high-power electrochemical storage devices.