Ionic-liquid-assisted synthesis of nanostructured and carbon-coated Li 3V2(PO4)3 for high-power electrochemical storage devices

Zhang X.,Böckenfeld N.,Berkemeier F.,Balducci A.,

Abstract

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 40 C, the LVP/N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide material delivered a reversible capacity of approximately 100 mA h g-1, and approximately 99 % of the initial capacity value was retained even after 100 cycles at 50 C. The excellent high rate and cycling stability performance make Li3V2(PO 4)3 prepared by ionic-liquid-assisted sol-gel synthesis a very promising cathode material for high-power electrochemical storage devices. Storage solutions: Carbon-coated Li3V2(PO 4)3 displaying nanostructured morphology is easily prepared by using ionic-liquid-assisted sol-gel synthesis. This material displays improved lithium-ion diffusion and electronic conductivity and thus enhanced charge-transfer properties. Li3V2(PO 4)3 prepared by this sol-gel route is a very promising cathode material for high-power electrochemical storage devices. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.