Electrospun Hierarchical LiV3O8 Nanofibers Assembled from Nanosheets with Exposed {100} Facets and their Enhanced Performance in Aqueous Lithium-Ion Batteries

Hierarchical LiV3O8 nanofibers, assembled from nanosheets that have exposed {100} facets, have been fabricated by using electrospinning combined with calcination. The formation mechanism of hierarchical nanofibers was investigated by X-ray diffraction and scanning electron microscopy. Poly(vinyl alcohol) (PVA) played a dual role in the formation of the nanofibers: besides acting as the template for forming the fibers, it effectively prevented the aggregation of LiV3O8 nanoparticles, thereby allowing them to grow into small nanosheets with exposed {100} facets owing to the self-limitation property of LiV3O8. This nanostructure is beneficial for the insertion/extraction of lithium ions. Meanwhile, the {100} facets have fewer and smaller channels, which may effectively alleviate proton co-intercalation into the electrode materials. Hence, the hierarchical LiV3O8 nanofibers exhibit higher discharge capacities and better cycling stabilities as the anode electrode material for aqueous lithium-ion batteries than those reported previously. We demonstrate that these hierarchical nanofibers have promising potential applications in aqueous lithium-ion batteries.