Heat transfer enhanced inorganic phase change material compositing carbon nanotubes for battery thermal management and thermal runaway propagation mitigation

Developing technologies that can be applied simultaneously in battery thermal management(BTM)and thermal runaway(TR)mitigation is significant to improving the safety of lithium-ion battery systems.Inorganic phase change material(PCM)with nonflammability has the potential to achieve this dual function.This study proposed an encapsulated inorganic phase change material(EPCM)with a heat transfer enhancement for battery systems,where Na_(2)HPO_(4)·12H_(2)O was used as the core PCM encapsulated by silica and the additive of carbon nanotube(CNT)was applied to enhance the thermal conductivity.The microstructure and thermal properties of the EPCM/CNT were analyzed by a series of characterization tests.Two different incorporating methods of CNT were compared and the proper CNT adding amount was also studied.After preparation,the battery thermal management performance and TR propagation mitigation effects of EPCM/CNT were further investigated on the battery modules.The experimental results of thermal management tests showed that EPCM/CNT not only slowed down the temperature rising of the module but also improved the temperature uniformity during normal operation.The peak battery temperature decreased from 76℃to 61.2℃at 2 C discharge rate and the temperature difference was controlled below 3℃.Moreover,the results of TR propagation tests demonstrated that nonflammable EPCM/CNT with good heat absorption could work as a TR barrier,which exhibited effective mitigation on TR and TR propagation.The trigger time of three cells was successfully delayed by 129,474 and 551 s,respectively and the propagation intervals were greatly extended as well.

Advances and challenges in thermal runaway modeling of lithium-ion batteries

The broader application of lithium-ion batteries(LIBs)is constrained by safety concerns arising from thermal runaway(TR).Accurate prediction of TR is essential to comprehend its underlying mechanisms,expedite battery design,and enhance safety protocols,thereby significantly promoting the safer use of LIBs.The complex,nonlinear nature of LIB systems presents substantial challenges in TR modeling,stemming from the need to address multiscale simulations,multiphysics coupling,and computing efficiency issues.This paper provides an extensive review and outlook on TR modeling technologies,focusing on recent advances,current challenges,and potential future directions.We begin with an overview of the evolutionary processes and underlying mechanisms of TR from multiscale perspectives,laying the foundation for TR modeling.Following a comprehensive understanding of TR phenomena and mechanisms,we introduce a multiphysics coupling model framework to encapsulate these aspects.Within this framework,we detail four fundamental physics modeling approaches:thermal,electrical,mechanical,and fluid dynamic models,highlighting the primary challenges in developing and integrating these models.To address the intrinsic trade-off between computational accuracy and efficiency,we discuss several promising modeling strategies to accelerate TR simulations and explore the role of AI in advancing next-generation TR models.Last,we discuss challenges related to data availability,model scalability,and safety standards and regulations.