Application of the Kramers–Kronig relationships in the electrochemical impedance models fit
Résumé
In lithium battery research, when we need to establish equivalent circuit based on impedance measurement, we can find several suitable circuit models. We usually use the chi-squared to determine the validity of equivalent models; when the chi-squared is less than 0.01, it indicates that those models have good fitting effect. In this case, we propose to verify the Kramers–Kronig transformation by extrapolating the data with equivalent circuit model and compare the residual errors of the Kramers–Kronig transform to determine the most suitable equivalent circuit model.