Online Detection of Lithium Plating Onset for Lithium-Ion Batteries Based on Impedance Changing Trend Identification During Charging Processes

Abstract

Lithium-ion batteries (LIBs) with a graphite anode are currently the most popular in electric vehicles. Lithium plating may occur in such LIBs due to an inappropriate charging strategy, worsening safety and cycle life. So far there is still a lack of effective online detection methods for the lithium plating onset. In the paper, the broadband impedance in the charging process was measured with a proposed simultaneous and fast measurement method. By comparing with the electrochemical impedance spectra measured in the quasi-steady state, the correlation between the impedance changing trend and the lithium plating onset was revealed. And a novel mechanism for the online detection of lithium plating onset was constructed based on the impedance changing trend identification, which is considered the main contribution of the paper. The proposed method can identify the lithium plating onset within a short delay. The maximum errors of the detection method are within 4.5% represented in state of charge, which is beneficial for optimal charging strategies to minimize the harm of lithium plating.