Voltage Hysteresis Cancellation for Fast Impedance Measurements of Lithium-ion Batteries in Short Relaxation Process

Electrochemical impedance spectroscopy (EIS) offers valuable insights into battery state monitoring and failure diagnosis; however, the impedance measurements are constrained by the high implementation costs. Within this context, the fast measurements of the battery impedance spectrum during a brief relaxation process are investigated in this work. The sources of impedance measurements’ inaccuracies are first analyzed, revealing that the undependable impedance responses are mostly attributed to voltage hysteresis effects. A zero-lag voltage hysteresis cancellation (ZVHC), integrated with a gradient descent algorithm, is then proposed for the extraction of voltage hysteresis components intertwined with the perturbation responses while eliminating the data latency. Experimental studies indicate that the proposed method is capable of accurately capturing the battery impedance responses ranging from 1.5 kHz to 0.1 Hz within 20 seconds. The requested resting period is less than 0.3% that of the conventional method. The impedance measurement results consistently match the reference trajectory under diverse operating conditions, confirming the high efficiency and validity of the proposed method.