Metrological examination of an impedance model for a porous electrode in cyclic aging using a 3-electrode lithium-ion cell with NMC111 | Graphite

In battery technology and electrochemical investigations, it is common to record impedance spectra to specific states (SoC, SoH, temperature, etc.). It is possible to determine appropriate parameters of the battery cell and assign them to the anode and cathode by a specifically selected electrical equivalent circuit diagram. A problem that arises here is that a statement about the reliability of the separation from the entire cell behavior is limited. By measuring the individual spectra of the anode and cathode through a 3-electrode cell and a subsequent single fitting it can be shown how valid the separation is. This Contribution aims to investigate an electrical model that depicts the separation of anode and cathode made of porous active materials.