Pulse-Driven Internal Resistance Dynamics Enable Dual-Function Lithium-Plating Diagnosis and Longevity Enhancement in V2G-Optimized Lithium-Ion Batteries

The lithium-plating phenomenon induced by low-temperature fast charging of lithium-ion batteries severely compromises their performance and safety. However, current lithium-plating detection methods predominantly rely on complex hardware systems with insufficient sensitivity, presenting significant challenges for implementation in increasingly prevalent Vehicle-to-Grid (V2G) scenarios. This study proposes a novel bidirectional pulse-current charging method designed to mitigate lithium plating and retard battery aging through intermittent pulse-current application. Experimental results verify a 30–50% reduction in capacity fade rate under fast charging conditions (≥0.5 C rates). Furthermore, by leveraging pulse-current characteristics, we reveal strong correlations between the evolution patterns of charge/discharge internal resistance and lithium plating. An in situ detection criterion requiring no additional hardware is established: the L-shaped decline of charging internal resistance under high-rate conditions coupled with the disappearance of defined reverse-hump curves in discharge resistance profiles serve as precise indicators of lithium-plating onset. Validation through SEM and relaxation voltage differential analysis confirms 100% detection accuracy. This methodology combines rapid detection capability, non-destructive nature, and compatibility with V2G applications, providing new perspectives for enhancing lithium-ion battery longevity and lithium-plating detection.