Thermochemical stability of Li–Cu–O ternary compounds stable at room temperature analyzed by experimental and theoretical methods

Compounds in the Li–Cu–O system are of technological interest due to their electrochemical properties which make them attractive as electrode materials, i. e., in future lithium ion batteries. In order to select promising compositions for such applications reliable thermochemical data are a prerequisite. Although various groups have investigated individual ternary phases using different experimental setups, up to now, no systematic study of all relevant phases is available in the literature. In this study, we combine drop solution calorimetry with density function theory calculations to systematically investigate the thermodynamic properties of ternary Li–Cu–O phases. In particular, we present a consistently determined set of enthalpies of formation, Gibbs energies and heat capacities for LiCuO, Li_2CuO_2 and LiCu_2O_2 and compare our results with existing literatur