Self-assembly of single layer V2O5 nanoribbon/graphene heterostructures as ultrahigh-performance cathode materials for lithium-ion batteries

Abstract

Two-dimensional (2D) heterostructures composed of the single layer V2O5 and graphene achieve good chemical diffusion of Li+, high conductivity and cycling stability. Hence, a simple and novel bottom-up approach has been proposed to build the true single layer V2O5 nanoribbon/graphene heterostructures. The single layer V2O5 nanoribbon, which has a thickness of 800 p.m. and are approximate 80 nm in wide, is combined with graphene as sandwich-like heterostructures through the layer-by-layer assembly method. The distinct heterostructures can effectively shorten the practical diffusion pathway for Li+ and improve the electrical conductivity of the overall electrode. Therefore, the as-prepared ultrathin V2O5 nanoribbon/graphene heterostructures exhibit excellent reversible capacity and stable cycling performance as a cathode material for lithium storage. Under the current density of 10 C, the electrode made from the ultrathin V2O5 nanoribbon/graphene heterostructures has an ultrahigh initial discharge capacity of 225 mAh g−1 (with corresponding coulombic efficiency of 99.6%) and a superior capacity retention of 92.8% after 600 charge and discharge cycles. In all, rapid ion and electron diffusions, which are the kinetic demands of alternative electrode material for lithium storage, will be satisfied by our single layer heterostructures.