Structural Transformation During Li/Na Insertion and Theoretical Cyclic Voltammetry of the δ-NH4V4O10 Electrode: A first-principles study

A double layer δ-NH4V4O10, due to its high energy storage capacity and excellent rate capability, is a very promising cathode material for Li-ion and Na-ion batteries for large-scale renewable energy storage in transportation and smart grids. While it possesses better stability, and higher ionic and electronic conductivity than the most widely explored V2O5, the mechanisms of its cyclability are yet to be understood. Here, we present a theoretical cyclic voltammetry as a tool based on first-principles calculations, and uncover structural transformations that occur during Li+/Na+ insertion (x) into (Lix/Nax)NH4V4O10.