Effect of electrode crosstalk on heat release in lithium-ion batteries under thermal abuse scenarios

Predicting thermal safety events of lithium-ion (Li-ion) batteries is significant in optimizing electrochemical systems with high thermal tolerance. The safety performances of Li-ion batteries are dictated by the thermal stability of their component materials both individually and collectively due to intricate exothermic reactions. Although the heat release of individual battery material has been thoroughly investigated, the safety hazards of inter-electrode chemical crosstalk under thermal abuse scenarios remain elusive and thus need a fundamental understanding. This study carries out a comprehensive thermal analysis of various material samples harvested from a commercial Li-ion cell using differential scanning calorimetry (DSC), complemented with full-cell accelerating rate calorimetry (ARC) and computational modeling. Reaction kinetics of electrolyte, wet cathode, wet anode and DSC-full cell samples imitating cell layered architectures are delineated to reveal substantial thermal interactions between electrodes. High-resolution kinetic parameters of reaction mechanisms are estimated using a synergy of Kissinger's method and mechanism-driven non-linear optimization strategies. A thermal abuse model is built based on the extracted kinetic parameters to simulate the cell-level thermal runaway phenomenon and compared with experimental observations, indicating how interlayer crosstalk effects significantly impact the thermal safety characteristics of Li-ion cell chemistries.