Investigating Temperature Variations in AC Impedance with an Indigenously Developed EIS Test-Bed

The adoption of electric vehicles (EVs) is increasing rapidly, necessitating improvements in vehicle performance, reli-ability, and safety. The battery pack plays a crucial role in an EV, and thus, its performance should be monitored and enhanced. However, the performance of a battery pack is affected by multiple factors, one of which is the changing environmental conditions of the area where the vehicle operates. Ideally, it is targeted that the battery pack output exhibits minimal variations with changes in climatic conditions. Impedance in battery is one of the commonly analysed parameter to determine the performance of pack. Analyzing impedance variations under diverse operating conditions is essential for understanding pack behavior. This paper presents a detailed electrochemical impedance spectroscopy (EIS) analysis of lithium-ion cells of different manufacturers at different temperature conditions, ranging from -10°C to 50°C, across a frequency range of 20 mHz to 10 kHz. The study offers insights for the research community and OEMs (Original equipment manufacturer) to identify cell chemistry and manufacturers that exhibit minimal variation with changes in temperature.