Batteries, Vol. 7, Pages 52: Combining the Distribution of Rest Times from EIS and Time-Domain Data for Parameterizing Equivalent Circuit Models associated with Lithium-Ion Batteries
Batteries doi: 10. 3390/batteries7030052
Authors: Leo Wildfeuer Philipp Gieler Alexander Karger
ECM are a widely used modeling approach regarding lithium-ion batteries in engineering applications. The RC elements, which display the dynamic loss processes of the cell, are usually parameterized by fitting the ECM in order to experimental data in possibly the time-domain or the frequency-domain. However, both varieties of data have limitations with regard to the particular observable time constants associated with electrochemical processes. This function proposes a solution to combine time-domain and frequency-domain measurement information for parameterization of REMOTE CONTROL elements by exploiting the particular full potential of the DRT. Instead of using only partial information from the DRT to supplement a conventional fitting algorithm, we all determine the parameters associated with an arbitrary number associated with RC elements directly from the DRT. The difficulties of automated deconvolution associated with the DRT, including regularization and the choice of an optimal regularization aspect, is tackled by using the L-curve criterion for optimized calculation of the particular DRT via Tikhonov regularization. Three different approaches in order to merge time- and frequency-domain data are presented, including a novel approach exactly where the DRT is simultaneously calculated from EIS and pulse relaxation measurements. The parameterized model to get an industrial 18650 NCA cell had been validated during an approval cycle consisting of continuous current and real-world automotive cycling and yields a relative improvement of over 40 % compared to a conventional EIS-fitting formula.