Bio-inspired carbon-stitched 3D boron nitride skeleton with enhanced thermal conductivity and waterproof performance for polyethylene glycol-based composite phase change materials

The development of energy storage technologies has emerged as a crucial initiative to address global energy challenges. However, existing phase change materials (PCMs) such as polyethylene glycol (PEG) suffer from inherent drawbacks including low thermal conductivity and poor shape stability. To tackle these issues, this study developed a carbon-stitching strategy that directs 1D boron nitride nanorod (BNNR) and 2D boron nitride nanosheet (BNNS) to co-assemble into a 3D skeleton inspired by natural abalone shell, thereby establishing an efficient heat transfer network. Experimental results demonstrated that the prepared PEG/BN c -10/UV composite PCM exhibited a thermal conductivity of 1.33 W · m −1  K −1 . Compared with pure PEG, this represented a 441 % increase in thermal conductivity, while the latent heat retention rate remained as high as 89 %. Through an ingenious design, the encapsulation with UV-curable resin not only prevents the leakage of PEG but also imparts waterproof properties to the composite. This expands the application of PCMs in underwater environments. This study provides a new design paradigm for the development of high-efficiency energy storage materials suitable for diverse environmental conditions.