Electrochemical investigations of Li2AuSn2

This paper deals with the electrochemical characterization of the lithium ternary intermetallic compound Li2 + xAuSn2 as an anode material for lithium cells. Li2 + xAuSn2 crystallizes in a tetragonal structure type with a three-dimensional [AuSn2] network forming distorted hexagonal channels which are occupied by lithium atoms. GITT and PITT techniques were employed to study the kinetics of lithium ion diffusion in this ternary stannide. The chemical diffusion coefficient of lithium, DLi, was determined as a function of the lithium non-stoichiometry x with respect to the formula Li2 + xAuSn2 having a maximum value DLi-max = 1.5 × 10− 6 cm2 s− 1 at the lowest lithium content of x = 0 at 25 °C. Accordingly, Li2AuSn2 is an interesting ternary intermetallic compound with good lithium and electron mobility, low potentials vs. metallic lithium and, thus, favourable as a model compound for anode materials in lithium batteries.