Scalable Sol–Gel Permeation Assembly of Phase Change Layered Film Toward Thermal Management and Light‐Thermal Driving Applications

Abstract Phase change materials (PCMs) are pivotal in thermal energy management and conversion applications owing to their exceptional thermal energy storage and release characteristics. However, persistent challenges such as poor thermal conductivity and leakage issues have impeded their widespread adoption. While existing approaches mitigate these challenges by constructing and incorporating 3D thermal conductive networks, they are constrained by discontinuous preparation methods and mold size limitations. Herein, a scalable sol–gel permeation assembly strategy is proposed to prepare phase change layered film by in situ filling polyethylene glycol (PEG) in aramid nanofibers (ANF)/graphene nanoplates (GNP) network. Befitting from the laminated network encapsulation effect of ANF and GNP, the phase change film demonstrates leak‐free and stable phase transition behavior, even after undergoing 500 heating/cooling cycles. Moreover, the resulting PEG/ANF/GNP layered film exhibits an impressive in‐plane thermal conductivity of 23.7 W mK −1 at GNP loading of 28.1 vol.%, rendering it suitable for thermal management applications in electronic devices. The phase change layered film possesses exceptional photo‐thermal conversion properties, maintaining temperatures exceeding 90 °C under a light power density of 200 mW cm − 2 . Capitalizing on the thermally induced flexibility of the phase transition film and its temperature‐dependent stiffness, its utility extended to developing a light‐thermal driving gripper.