Crystal Structure and Electrochemical Behavior of Li₂CuP: a Surprising Reversible Crystalline−Amorphous Transformation

Abstract

In situ XRD experiments on an electrochemical cell show that extraction of Li from crystalline Li2CuP (oxidation) is accompanied by a first-order transition in the solid state at room temperature to form a quasi-amorphous delithiated phase. The process is readily reversed on reduction, resulting in recrystallization of the original Li2CuP phase.