From Aging Mechanism to Safety Response: A Framework for Lithium Plating Detection and Safety Assessment

Thermal runaway poses a substantial safety concern in high-energy lithium-ion batteries. Understanding aging-induced degradation and developing reliable detection strategies are, therefore, essential. This study compares the thermal safety characteristics of commercial 3.5 Ah 18650 cylindrical cells containing nickel-rich cathodes and graphite/SiO x anodes that had been aged using dynamic WLTP driving cycles and continuous laboratory cycling conditions with and without lithium plating at different SoH and SoC levels. This work focuses on the formation, detection, reversibility, and safety implications of low-temperature-induced lithium plating using accelerating rate calorimetry (ARC), differential voltage analysis (DVA), galvanostatic electrochemical impedance spectroscopy (GEIS), and Post-Mortem analysis with glow discharge optical emission spectroscopy (GD-OES) depth profiling. We already observe lithium plating in the initial cycles and also a continuous growth of plated lithium during continuous cycling with 0.85 C at 0 °C. Cells with low-temperature-induced lithium plating exhibit pronounced safety degradation, with the self-heating onset temperature reduced by up to 50 °C regardless of the load profile. Subsequent heating to 45 °C for 48 h partially restores safety, leaving the thermal runaway mostly unaffected but increasing the self-heating onset temperature by 25 °C–40 °C depending on SoH level. These results underscore the importance of lithium plating detection to improve lithium-ion battery safety.