Using Numerical Models to Accelerate Electrolyte Transport Parameter Identification

Abstract

A new electrolyte transport parameter identification methodology, based on the numerical solution of a symmetric Li–Li cell model, is presented. In contrast to available techniques in the literature, where small concentration perturbations are generated in testing setups and linearization is assumed to identify transport properties for the initial salt concentration, large currents are used here to excite nonlinear dynamics able to reveal concentration dependent transport properties. This approach allows a significant reduction in the experimental effort. The proposed methodology is applied to two synthetic experiments. Firstly, an ideal case (where all difficulties associated to stripping and plating dynamics on Li metal surface are neglected) is considered in order to show both the details of the proposed methodology and its performance (specially its robustness, including the effect of the noise level in the voltage measurements in the experiment). A second case considers the effect of complex stripping and plating dynamics to show that, provided (macroscopic) modelling/identification of this dynamics is carried out, the proposed methodology is still able to accurately identify electrolyte transport properties using a simple experimental test setup.