Modular assembly strategy to construct lightweight thermal management system by developing high-stable phase change material units

• A novel CPCM overcoming the trade-off between stability and latent heat is prepared. • A modular assembly strategy is proposed for modules in TMS based on the novel CPCM. • New j-CPCM module forms developed airflow channels and enlarged heat transfer area. • j-CPCM module shows better cooling performance than classical massive CPCM module. • j-CPCM module saves 45 wt% CPCM dosage and increases energy density by 19 Wh·kg −1. The low mechanical/thermal stability of existing composite phase change material (CPCMs) leads to bulky and low-efficient structures of the battery thermal management system (TMS). Herein, we successfully overcome the trade-off relationship between the mechanical/thermal stability and thermal storage capacity of the CPCM by designing a phase changeable polymeric skeleton (PCPS). Then, a novel modular assembly strategy is proposed to realize the lightweight, high-efficient cooling and smart assembly of the CPCM module. The PCPS provides high mechanical/thermal stabilities and an intrinsic latent heat of 94 J·g −1 . Thus, its proportion can be increased to 56 wt% without greatly sacrificing the latent heat, realizing the preparation of half-jacket-units and the subsequent smart assembly. The jacket-unit assembly CPCM module forms developed air-flow channels and heat transfer area. Consequently, it demonstrates better cooling performance than classical massive module. For instance, its temperature can be reduced by 22.6 °C at 3-C discharge under 35 °C.