3D layered nanostructure of vanadium nitrides quantum Dots@Graphene anode materials via In-Situ redox reaction strategy

Abstract

• An anode material with 3D layered nanostructure is fabricated by in-situ strategy. • The insertion of the vanadium nitride quantum dots expands rGO layer spacing. • There are numerous electrolyte transfer channels and electrochemical reaction area. • High capacity of 272.9F g −1 and good cyclic stability over 10, 000 cycles. The Anode materials are predominant and play key role to get high power and high energy densities for energy storage device. Recently, graphene is extensively investigated as anode material for energy device, because of its amazing superlative properties. Nevertheless, re-stacking of graphene is an important technological problem for their electrode structure, which strongly reduces the active surface area of graphene, and leads to lower capacitance of the material. Vanadium nitride exhibits high theoretical capacitance, good electric conductivity, and wide potential range, but its weak rate capability and cycling stability limits the practical application. In this work, vanadium nitride as quantum dots (1 ~ 3 nm) combine with graphene layers have been fabricated by using a novel method of in-situ redox reaction and heat-treatment. Fascinatingly, the anchored vanadium quantum dots expand the interlamellar spacing of graphene and increase dispersion of single-layer graphene, which brings more channels for move of electrolyte, and more electrochemical active site for absorb of ions. Compared the pristine graphene and vanadium nitride, the prepared vanadium nitrides quantum dots anchored graphene anode materials shows high capacity of 272.9F g −1 at 0.5 A g −1 with good cycling stability of 84% over 10, 000 cycles. The new anode materials could be further used in the battery systems, and the novel fabrication method also could be applied in the other fields, such as catalysis, adsorption, sensors, drug delivery, and so on.