Revealing the relationship between external pressure and lithium plating of pouch lithium-ion batteries based on in-situ impedance and relaxation voltage

Lithium plating during fast charging poses a significant threat to battery lifespan and safety. However, conventional lithium plating detection methods relying on specialized equipment fail to meet the practical demands of fast charging technology development. Novel approaches are required to overcome these limitations. Relevant studies indicate a strong correlation between the mechanical characteristics of batteries and lithium plating. This study, leveraging relaxation voltage and in-situ impedance measurements, revealed the relationship between force characteristics and lithium plating. The results indicate that the differential force curve can be used to characterize the onset of lithium plating. In the absence of lithium plating, the differential force plot does not exhibit a prominent second peak. By comparison, if lithium plating occurs, the second peak will be relatively pronounced, which corresponds to the onset of lithium plating. The proposed online lithium plating diagnosis method based on differential force detection, which can be integrated into the current battery management system (BMS), enables dynamic adjustment of the charging current. By detecting the onset of lithium plating and identifying its initial stage, the BMS can take proactive measures to suppress its further progression.