Correlating lithium plating quantification with thermal safety characteristics of lithium-ion batteries

Abstract

Lithium plating is one of the most safety-critical side reactions in lithium-ion (Li-ion) batteries. It is likely to occur under overcharge or fast-charge scenarios when the overwhelming Li-ion flux exceeds the intercalation or diffusion limits of the graphite host structure. Adverse lithium plating will cause the loss of lithium inventory to accelerate degradation and reduce the cell safety limits due to high thermal instability. Correlating lithium plating quantification with cell-level thermal safety characteristics remains a critical bottleneck. In this study, we derive correlations between the total plating energy and kinetic parameters of lithium plating induced exothermic reactions. Three-electrode electrochemical analytics of Li-ion pouch cells, under isothermal and thermal gradient conditions, are analyzed based on decoupled anode potential for lithium plating signatures. Post-mortem analysis reveals the distribution, morphology, and chemical state of lithium plating regimes. Accelerating rate calorimetry is employed to evaluate cell thermal hazards, followed by thermos-kinetic analysis to reveal correlations between the safety factor and plating energy. This work reveals the evolution of lithium plating induced early cell exotherm and total heat generation, promoting the development of real-time battery safety monitoring based on the online detection of lithium plating severity.