Impedance modeling-based online detection of lithium plating in lithium-ion batteries

Online detection of lithium plating is critical for fast charging of lithium-ion batteries. Impedance-based method has shown great potential due to its high sensitivity and implementation feasibility. However, an impedance modeling-based method for variable current fast charging has not yet been developed. In this study, the impedance behavior was first investigated through experiments. To enable online detection of lithium plating onset, an impedance model based on the Butler-Volmer equation was developed to predict impedance evolution during charging. By integrating this model with an extended Kalman filter, lithium plating onset can be detected when the deviation between the predicted and measured impedance exceeds a defined threshold. With a detection threshold of 3%, the maximum delay in identifying the onset of lithium plating does not exceed 5% SoC. Although a short delay is inevitable, aging experiments demonstrate that this delay does not result in irreversible plating. Consequently, the proposed method offers a practical way for real-time lithium plating detection and exhibits great potential in battery fast charging.