Dynamic evolution of effective thermophysical parameters in lit 2027 Applied

Characterizing the thermophysical evolution preceding overcharge-induced thermal runaway (TR) remains important for improving the thermal safety modeling of lithium iron phosphate batteries. Fixed thermophysical parameters remain commonly used in reduced-order battery thermal models, which limits representation of the evolving thermal response during overcharge-induced TR. This study proposes a temperature gradient inversion method integrated with a coupled electrochemical-thermal-mechanical framework to dynamically identify these transient parameters. The method characterizes the coupled evolution of effective lumped thermal resistance ( R C ) and heat capacity ( C C ) during overcharging. R C exhibits pronounced stage-dependent fluctuations and reaches a maximum of 5.2 K/W, consistent with progressive interfacial and structural changes during overcharging. Concurrently, C C evolves from an initially stable regime through progressive attenuation to terminal depletion. These parameter trajectories provide effective dynamic indicators of the evolving internal thermal state under the investigated overcharge conditions. Compared with the constant-parameter reference, incorporating the identified dynamic thermophysical parameters reduces the core-temperature root mean square error by up to 64.5% for independent-cell validation. This work provides a physics-based dynamic modeling framework for representing overcharge-induced TR thermal evolution and establishes.