Rapid Optimization of Thermal Runaway Propagation Inhibition in Composite Phase Change Material-based Battery Module

Thermal runaway propagation (TRP) in lithium-ion battery applications causes severe safety hazards. Utilizing phase change material (PCM) with optimized thermal properties can effectively buffer heat diffusion among batteries, thereby potentially inhibiting TRP. However, the realization of such a goal requires an efficient and reliable model along with an effective optimization strategy. Herein, a lumped thermal resistance network is developed for the PCM-based battery module, and the TRP process is calculated in two minutes using the thermal-electrical analogy method with adequate accuracy. This research investigates the impact of thermal runaway (TR) trigger locations within the module, alongside the influence of diverse thermophysical parameters of composite PCM, on the characteristics of TRP. The results show that the TRP risk level varies dramatically across the trigger locations, from which the inhibition of TRP at edge locations is more difficult than that at middle locations. In the range of thermal conductivity from 1 to 21 W m
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, the composite PCM with higher thermal conductivity only has a highly effective inhibition performance to TRP triggered in middle locations. Besides, the inhibition effect can be improved by adjusting the PCM thermophysical parameters (such as decreasing phase change temperature, increasing phase change enthalpy or specific heat capacity), with an impact degree of phase change temperature < phase change enthalpy < specific heat capacity. Furthermore, to balance the TRP risk level of all locations, an optimization strategy of unequal spacing distribution with fixed module volume is proposed. For an optimized module based on composite PCM with thermal conductivity of 1 W m
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, the demand for preventing TRP at all locations is reduced by 42% (measured by specific heat capacity) compared to the original module with equal spacing distribution.