Abstract
Contrary to stationary storage, mobility applications require batteries with both a high energy density (e.g., vehicle autonomy) and a large power capability (e.g., fast-charging, or sudden power calls). Batteries designed for high-energy applications usually embed thick electrodes that are subject to substantial limitations, in part due to the sluggish transport Li+ ions in liquid electrolytes. Electrolyte characterization is therefore crucial, both in terms of formulation and for the simulation of battery systems (requiring accurate parametrization to get realistic predictions). In this Ph.D. thesis work, we review the different methods for the characterization of liquid electrolytes for lithium-ion batteries. Then, the transport properties are determined at different concentrations for the LiPF6 in EC/DEC (1:1 weight proportions) electrolyte (considered binary). Herein, the transport and thermodynamic properties of interest for the electrolyte are the diffusion coefficient D’, transference number t_+^0, conductivity kappa, and thermodynamic factoralpha'. The transport properties are determined by applying a galvanostatic pulse to the multi-electrode cell and by measuring the voltage response of the electrolyte between the N-1 pairs of reference electrodes (REs) (N is the number of REs in the cell). D', t_+^0 and kappa_eff are determined using data processing methods combining inverse modeling and analytical calculations. The thermodynamic factor alpha' of the electrolyte is calculated from the output data of the multi-electrode cell and the alpha' t_-^0 determined using concentration cells