Flexible Membrane Device Constructed Based on Azopyridine Derivatives Synergized With Solid–Solid Phase Change Polyurethane for Coharvesting of Photochemical and Thermal Energy

Abstract Azo‐based photoswitchable molecules can undergo configurational transformations by tuning the wavelength of incident light, thereby enabling efficient energy storage. Polymer‐based solid–solid phase change materials are capable of storing and releasing thermal energy through surroundings temperature regulation without experiencing macroscopic morphological changes. There is growing interest in constructing hybrid systems that enable synergistic collection and release of energy in thermal management systems. Herein, a series of meta ‐azopyridine compounds with electron‐donating and electron‐withdrawing groups are synthesized, the azopyridine derivative with the highest energy density can reach up to 312 J g −1 . Meanwhile, polyethylene glycol is employed as the phase change component to synthesize solid–solid phase change polyurethanes featuring robust mechanical properties and favorable shape stability. Most importantly, a flexible energy‐storage device is innovatively integrated employs the above‐mentioned two systems, capable of coharvesting photon and phase change energy reaching up to 388 J g −1 . The temperature regulation capability of the devices through the storage and release of photothermal and phase change energy is demonstrated as a thermal‐insulation material, showing potential application in external thermal‐insulation aspects for transport pipelines.