Electrospun Li₃V₂(PO₄)₃/carbon nanofibers as freestanding cathodes for high-performance zinc-ion batteries

Li3V2(PO4)3 is a promising high-voltage cathode for zinc-ion batteries, but it suffers from a poor electronic conductivity and vanadium dissolution in aqueous electrolytes. The growth of carbon-coated Li3V2(PO4)3 (LVP@C) nanoparticles on carbon nanofibers (CNFs) has been achieved by an electrospinning technique followed by calcination. The protective carbon coating prevents the aggregation of the LVP nanoparticles and suppresses V dissolution by preventing direct contact with aqueous electrolytes. The CNFs derived from the electrospun nanofibers provide a 3D network to increase the electronic conductivity of the LVP electrode, and the LVP@C-CNF hybrid film can be directly used as a freestanding cathode for zinc-ion batteries without adding conductive additives and binders. A mechanism for the formation of a uniform and continuous carbon coating has been proposed. This nanostructure, combined with the uniform and intact carbon coverage, significantly increases the electronic conductivity. This LVP@C-CNF freestanding electrode has an excellent rate capability (47.3% retention at 2 C) and cycling stability (61.2% retention after 100 cycles) within the voltage range 0.6 V to 1.95 V and is highly suitable for zinc-ion battery applications.