Applicability analysis of equivalent circuit model parameter identification method for lithium-ion batteries

Abstract The equivalent circuit model (ECM) of lithium-ion batteries is commonly utilized for state of charge (SOC) online estimation. In recent years, researchers have proposed different ECM identification methods according to their own needs, so the application scenarios of each method are different. The ECM identification consists of two steps: (1) obtaining the open circuit voltage curve and (2) obtaining the parameters of ECM. Since the OCV curve acquisition process is common, the difference between these estimation methods lies in the different parameter estimation methods. Since high dynamic profiles and low dynamic profiles have different influences on parameter estimation, this paper analyzes three modeling methods for SOC estimation are compared. Finally, the selection basis of ECM identification is provided.