Highly efficient lithium container based on non-Wadsley-Roth structure Nb18W16O93 nanowires for electrochemical energy storage

Abstract

The tungsten niobium oxides that belong to the well-known Wadsley-Roth shear structure have been already studied as the high-performance anode materials over the past several years since these materials can provide the additional vacuum site for accommodating lithium ions. Now, a novel anode material Nb18W16O93 which has a tetragonal tungsten bronze type structure is firstly reported in this paper. This material exhibits the good electrochemical performance. Upon the modification of its surface morphology, the electrochemical performance for Nb18W16O93 nanowire has been greatly improved. Nb18W16O93 nanowire shows the reversible specific capacity of 195 mAh g−1 when the current density is 100 mA g−1 and it can reach 153 mAh g−1 even at 1000 mA g−1. Meanwhile, the lithiation/delithiation mechanism and its corresponding structural change during the charge and discharge process are also carried out by an in-situ XRD technique. The result shows that Nb18W16O93 nanowire has excellent electrochemical reversibility and structural stability. Consequently, Nb18W16O93 nanowire can be employed as a novel anode material for lithium ion batteries.