Efficient electrode material of restacked Na–V2O5–graphene nanocomposite for Na-ion batteries

Efficient electrode material of Na–V2O5–reduced graphene oxide (rG-O) nanocomposite is synthesized by the restacking of anionic component nanosheets with Na+ ions at room temperature. The restacked Na–V2O5–rG-O nanocomposite shows layer-by-layer-ordered structure of V2O5/rG-O nanosheets and Na+ ions with mesoporous stacking structure and expanded surface area. Upon the restacking with rG-O, the pentavalent V5+ oxidation state and layered lattice of vanadium oxide nanosheet remain unchanged. The composite formation with rG-O leads to a significant enhancement of the discharge capacity from ~50 to ~150mAh g−1 as cathode material for Na-ion batteries, underscoring the usefulness of restacking between metal oxide and rG-O nanosheets in exploring novel nanocomposite electrode materials. [Display omitted] •The first synthesis of mesoporous Na–V2O5–reduced graphene oxide (rG-O) nanocomposite•A significant enhancement of the discharge capacity of V2O5 upon coupling with rG-O•Mixed colloid of V2O5 and rG-O nanosheets as excellent precursor for Na-ion electrode