Reprocessable form-stable phase change materials with high latent heat via dynamically cross-linked polysiloxane networks for efficient thermal energy storage

Phase change materials (PCMs) present significant potential for achieving zero-energy thermal management, owing to their excellent thermal storage capabilities and stable phase-change temperatures. Nevertheless, the issues of liquid leakage, the solid rigidity and non-circularity of current PCMs pose longstanding challenges for the implementation of PCM-based thermal regulation. Herein, we developed a recyclable form-stable phase change materials (FSPCMs) with high latent heat for efficient thermal storage from utilizing the dynamically cross-linked polysiloxane networks as the supporting networks and n-octacosane (C28) as the latent heat material. These FSPCMs demonstrate enhanced phase change enthalpies, excellent mechanical properties, and exceptional recyclability. The “active” ammonium silanate ion pairs inside the supporting networks facilitate rapid exchange of Si[sbnd]O bonds, thereby promoting the formation of an effective dynamic cross-linked polysiloxane. Additionally, integrating thermally conductive fillers such as micron-sized graphite sheets into these FSPCMs, the composites exhibit promising applications in thermal management applications.