Abstract
State of Health (SOH) monitoring is critical for the efficient and reliable operation of lithium-ion batteries, particularly in electric vehicle applications. Electrochemical Impedance Spectroscopy (EIS) is a widely used non-destructive technique for estimating the SOH of batteries, as it provides detailed insights into the battery's internal condition across a range of frequencies. In this study, datasets collected from four cylindrical lithium-ion batteries manufactured by Molicel of model INR-21,700-P42A under various operating conditions were presented. Each cell was tested under a range of operating conditions, like four State of Charge (SOC) levels: 80%, 60%, 40%, and 20%; five current amplitudes: 30 mA, 50 mA, 100 mA, 500 mA, and 1 A; and three rest times: 30 min, 1 hour, and 2 h. The experiments were conducted using an Arbin battery cycler, and EIS tests were performed in galvanostatic mode using a Gamry Interface 5000P Potentiostat. The experiment resulted in 60 unique test conditions per battery (4 SOC levels × 5 current amplitudes × 3 rest times). The entire experimental procedure was repeated for four battery cells, resulting in a total of 240 impedance data. The resulting dataset consists of frequency, real and imaginary components of impedance data. This data is used to generate Nyquist plots. This plot provides information about different parameters like Ohmic resistance, solid electrolyte interface capacitance and resistance, charge transfer resistance, double layer capacitance and ionic diffusion. These parameters are sensitive to battery aging and can be used to assess the battery's SOH.