Interpretation of processes at positive and negative electrode by measurement and simulation of impedance spectra. Part II: Concentration limitation

Impedance measurements of both electrodes of a flooded OEM SLI battery at various SOC and with various direct currents have been measured. For each part of the impedance spectra, an electrochemical process is proposed and implemented in a simulation model. By simulation of impedance spectroscopy, spectra of the model are obtained and compared with the measurement. In the first part, the focus was put on inductive semicircles, while in this second part, concentration limitation and its appearance in impedance spectra is investigated.

► Impedance spectroscopy of both electrodes of lead-acid batteries. ► Spectra contain inconsistencies according to Kramers–Kronig check. ► Inconsistencies can be simulated by concentration limitation.