Practical Analysis of Fast Measurement of Electrochemical Impedance Spectra Based on Wavelet Transforms

The rapid measurement method of electrochemical impedance spectroscopy (EIS) based on continuous wavelet transform (CWT) provides an efficient and convenient technical means for lithium battery fault diagnosis and on-site inspection. However, the influence of environmental factors such as charge/discharge multiplier, state of charge (SOC) and temperature on the state of Li-ion batteries cannot be ignored during practical application. Therefore, this study builds an experimental platform on the basis of wavelet transform technology and systematically analyzes the effects of these environmental factors on the impedance spectrum of the battery by combining the relaxation time distribution method (DRT) with the equivalent circuit fitting method. Through this analysis, it aims to provide scientific basis and reference for real-time fault diagnosis and performance testing of lithium batteries, in order to improve the diagnostic accuracy and reliability of the battery management system in the actual operating environment.