A Fast Screening and Recombinant Method Based on Short-Time Pulse Discharge and Electrochemical Impedance Spectroscopy for Decommissioned Power Batteries

Abstract

Aiming at the problems of low screening efficiency, high energy consumption and low grouping rate of decommissioned power batteries at this stage, a fast screening and recombinant method based on short-time pulse discharge and electrochemical impedance spectroscopy (EIS) for decommissioned power batteries is proposed. More than 200 decommissioned lithium iron phosphate power batteries of the same type and different batches were tested and analyzed by short-time pulse discharge and EIS. Then, the obtained pulse voltage difference, DC internal resistance, EIS curve shape characteristics and EIS equivalent circuit model parameters are used as screening indexes, and a mathematical model is established to realize the rapid and effective sorting and reorganization of decommissioned power batteries. The experimental results show that this method has low energy consumption, the average test time of single cell is less than 20 min, and the consistency index is good after grouping, so it has great practical value in engineering.