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

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 lithium plating onset. In this article, 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. 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 this article. 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 the state of charge (SOC), which is beneficial for optimal charging strategies to minimize the harm of lithium plating.