Overcharging Investigation in Lithium-Ion Batteries Using Electrochemical Impedance Spectroscopy and Relaxation Time Distribution

The lithium-ion battery (LIB) has a complex and changeable electrochemical behavior. It is difficult to diagnose the state of LIBs and predict the state of LIBs. Electrochemical impedance spectroscopy (EIS) is a kind of effective measuring method which can provide important information about internal phenomena of battery. To convert EIS data from the frequency domain to the relaxation time distribution function (DRT), which is referred to as DRT or the τ-domain. This separation and visualization of potential electrochemical processes can be done. The diagnosis of overcharging in LIBs is of paramount importance in guaranteeing the system's thermal stability and long-term serviceability. Three groups of batteries in this study were overcharged from 0%SOC to 107% SOC, then the time constants and polarization resistance values of loss-related processes were obtained through EIS and DRT methods. And also looked at how the temperatures depended on it, with all the proper physics explained.