Calculation of the distribution of relaxation times for characterization of the dynamic battery behavior

Abstract

Impedance spectroscopy is widely used for characterization of batteries. Beside model based approaches for data analysis, the impedance spectra can be used to calculate a distribution of relaxation times (DRT). These DRT spectra can be seen as the time domain representation of the linear battery behavior as it describes the relaxation for different time constants. In contrast to the impedance spectra, it can be used to directly simulate the linear response of the battery. In this paper a calculation method for the distribution of relaxation times is shown that employs an iterative regularization scheme combined with stochastic methods for determination of the regularization parameters. For preserving peaks in the relaxation spectra during calculation edge preserving techniques are implemented.