Research on the Performance Evaluation of Lithiumion Battery Cascade Utilization Based on Impedance Spectrum

摘要

In order to evaluate the performance of lithium-ion battery in cascade utilization, a fractional order equivalent circuit model of lithium-ion battery was constructed based on electrochemical impedance spectrum, and the parameters of the model were identified by complex nonlinear least square regression. Using fractional calculus as a tool, the SOP estimation of lithium-ion battery based on impedance spectrum model is realized. A BP neural network is constructed and trained by impedance spectrum data of different aging stages in cycle aging experiment. The SOH estimation of lithium-ion battery based on high sensitivity parameters is realized. The relative error of SOP/SOH estimation is less than 10% and 4%, respectively.