Poly(ethylene glycol)-Based Reprocessed Solid–Solid Phase Change Materials with Dynamic Semi-interpenetrating Network for Efficient Energy Storage and Thermal Management

Reprocessed solid–solid phase change materials (RSSPCMs) possess significant potential for energy conservation and sustainable energy utilization, making them a popular choice for battery thermal management (BTM). Currently, the design of RSSPCMs still faces challenges in terms of their enthalpy efficiency and mechanical properties. In this study, a typical semi-interpenetrating network (semi-IPN) has been constructed by incorporating a dynamic disulfide cross-linking network in PEG. It displays 99.97% enthalpic efficiency and 90.7% mechanical damage healing efficiency. Their latent heat (75.86–110.64 J/g) and phase change temperature (49.9–57.4 °C) can be easily tailored by adjusting the PEG. The semi-IPN structure provides RSSPCMs with high thermal reliability, thermal stability, shape stability, and excellent mechanical properties. Furthermore, 7.5–9.7 MPa of tension mechanical stress and 430–640% of strain demonstrate that the RSSPCMs possess excellent self-healing ability after exposure to thermal/infrared stimulus without the changes of chemical structure or phase change behavior. This work delivers a new route to develop thermal energy storage (TES) materials with high enthalpy efficiency, self-healing capabilities, and reprocessability.