Experimental and theoretical investigation of Li-ion battery active materials properties: Application to a graphite/Ni0.6Mn0.2Co0.2O2 system

The knowledge of active materials properties and their evolution with aging is crucial to simulate predict a high reliability the electrochemical performance lithium-ion batteries. In view developing more accurate physics-based Lithium Ion Battery (LIB) models, this paper aims present consistent framework, including both experiments theory, in order retrieve material commonly used electrodes made graphite at negative Ni0.6Mn0.2Co0.2O2 (NMC 622) positive, as function stoichiometry. To measure equilibrium potential solid diffusion coefficient, Galvanostatic Intermittent Titration Technique (GITT) measurements were used. Electrochemical impedance spectroscopy (EIS) reference performed determine exchange current density using transmission line model. measured stoichiometry dependence these three has been further analyzed, based on thermodynamic considerations. For positive material, model proposed highlighting non-ideal behavior lithium inside host material. relations available literature are not directly transposable suggesting necessity account for supplementary terms. Nevertheless, dependent laws determined same definition go already beyond most reported values can be increase predictability multi-physics battery models.