The thermodynamic properties of electrode materials for lithium batteries are directly linked to electrochemical performance, heat generation and safety during electrochemical cell operation. However, such thermodynamic data are largely missing even for the most important cathode materials e.g. Li(Ni,Mn,Co)O2 (NMC: 111, 442, 532, 622, 811), LiMn2O4 (LMO) and their derivates. The situation is similar for anode materials based on Li4Ti5O12 (LTO) and tin-base alloys, respectively. Therefore, we aim at investigating thermodynamic properties and phase diagrams and link them to electrochemical and thermal cell behavior. The fundamental experimental research includes investigations of heterogeneous phase equilibria, heat capacities, enthalpies, chemical potentials as well as entropy measurements on both half and full electrochemical cells. CALPHAD-type thermodynamic models and descriptions of ternary and multicomponent systems are then used to calculate reversible open circuit voltages of electrochemical (half) cells. The thermodynamic datasets and additional thermophysical data can then be used for an advanced application-oriented electrochemical-thermal modeling.