Consistency Screening Method of Lead Acid Battery Monomer Based on Characteristic Parameters of Electrochemical Impedance Spectroscopy

When the lead-acid battery is in actual use, not only does the charge and discharge chemical reaction occur inside the battery, but also many side reactions occur at the same time, which cause the irreversible consumption of lithium ions, making the battery capacity decline, and directly affecting the battery's charge and discharge capacity. Long-term use of the battery internal resistance increases, capacity decreases, and health life is shortened, the most common aging mechanism can be summarized as: lithium inventory loss (LLI), active material loss (LAM), and impedance increase, compared with the new battery, decommissioned power battery from different use environment and operating conditions, poor consistency. The purpose of decommissioned battery sorting is to solve the problem of battery consistency and grouping. As a non-invasive measurement technique, electrochemical impedance spectroscopy measures the impedance values of batteries at different frequencies to reflect the internal state of batteries. In this paper, the electrochemical impedance spectra of 104 retired lead-acid batteries were measured. According to the characteristic parameters of impedance spectrum, 24 lead-acid batteries with good capacity consistency were selected from 104 decommissioned batteries.