New Prelithiated V2O5 Superstructure for Lithium-Ion Batteries with Long Cycle Life and High Power

Vanadium pentoxide (V2O5) is an attractive high-capacity cathode material for lithium-ion batteries but is limited by the poor structural stability. In this work, we report the synthesis and properties of a new lithium-ordered superstructure of Li0.0625V2O5 through controlled prelithiation treatment. Compared to VO5 square pyramids in a pure alpha-V2O5 structure, the distorted VO5 square pyramid in this superstructure imparts an intrinsic layer structure with improved stability, expanded c-plane spacing, as well as expansion in the a-axis. In the voltage range of 2.5-4.0 V vs Li/Li+, Li0.0625V2O5 nanobelts with lithium-ordered superstructures exhibit a specific capacity up to 215 mAh g(-1), ultrahigh cycling capability, and high rate capability. Cyclic voltammograms of lithium insertion into Li0.0625V2O5 nanobelts also demonstrate two new pairs of reversible pseudocapacitive peaks in addition to the ordinary peaks of Le insertion into the pure orthorhombic alpha-V2O5.