Application of Localized Electrochemical Impedance Spectroscopy to Lithium‐Ion Cathodes and in situ Monitoring of the Charging Process

Localized electrochemical techniques, which have been developed for the last few decades, are useful tools for the examination of surface properties and processes in many different fields of research. Especially localized electrochemical impedance spectroscopy (LEIS) is a promising technique for many applications, as it combines the advantages of conventional electrochemical impedance spectroscopy (EIS) and localized techniques. In this study, requirements and difficulties regarding the application of LEIS to lithium ion electrodes are illustrated and different aspects of a useful experimental setup are introduced. Furthermore, some basic observations regarding the development of the system's Ohmic and charge transfer resistances during the electrode's charging process are presented.