Facile synthesis of N-doped reduced graphene oxide matrix-covered porous Fe2VO4 hybrid composite nanostructures as anode material for lithium-ion batteries

Abstract

For iron vanadium-based lithium (Li)-ion batteries (LIBs), enhancing solidity as well as exploring storage mechanism is important. Herein, a facile hydrothermal method is employed to fabricate N-doped reduced graphene oxide-wrapped porous iron vanadate (FVO@N-rGO) hybrid composite nanostructures (HCNSs), followed by the calcination under the N2 atmosphere. The as-prepared FVO@N-rGO HCNSs are used as an anode material for LIBs. The FVO@N-rGO HCNSs electrode delivers a high reversible specific capacity of 711 mA h g−1 at 100 mA g−1 and durable cycling life (226 mA h g−1 at 3000 mA g−1). The Li+ intercalation kinetics (from cyclic voltammetry analysis) reveal that the Li storage capacity of FVO@N-rGO HCNSs is normally dominated via a pseudo-capacitive behavior. A full cell using commercial LiNi0.3Mn0.3Co0.3O2 (NMC111) as a cathode and pristine FVO nanospheres and FVO@N-rGO HCNSs as an anode is also fabricated. The obtained good reversible capacity, stability, and rate capability may be due to the synergetic result of three-dimensional HCNSs construction and porous morphology with a large surface area, which offers void space to shield size expansion/contraction along with reducing the diffusion coefficient for Li ions/electrons in the cycling process. Thus, this study gives a deep understanding of improving the cell performance of iron vanadium-based LIBs.