Modelling of thermal runaway propagation in lithium-ion battery pack using reduced-order model

The study presents a thermal runaway propagation (TRP) model developed by coupling the reduced-order thermal and thermal runaway (TR) models at the mini-module, real-module, and pack levels. Comparing to the ANSYS thermal model, the maximum error of reduced-order model was less than 1.2%. Moreover, the speed is 12 times faster. Furthermore, the TRP models of the mini-module with 4 cells and real-module with 18 cells were validated experimentally. The simulation error of the mini-module test was less than 3.52%. The simulation of the real-module revealed different propagation modes. The TRP time though the whole module was 1906.2s. Finally, the model was extended to the pack level. The propagation characteristic on the triggered module was quite similar with that in the real module. The propagation time of the initiated module in the pack was 1069.4s, which is faster than the propagation time in the real-module. The TRP between the modules was found in the battery pack and accelerated by the cooling plate. The reduced order TRP model can well simulated the TRP of battery pack from mini-module level to the pack level, which is possible to guide the safety design method on the battery pack.