Investigating the Applicability of Electrochemical Impedance Spectroscopy for Parallel-Connected Lithium-ion Battery Modules

Electrochemical impedance spectroscopy (EIS) is a non-destructive method of testing that provides information on the internal processes within a cell. Previous studies using EIS have primarily focused on the cell level, with few studies conducted at the module or pack level. This study applies EIS to eight 4P1S modules at varying states-of-charge (100%, 50%, and 0%) and degrees of aging. At 100% SOC, the modules show relatively high impedance …