Aerogel‐Functionalized Phase Change Materials toward Lightweight and Robust Thermal Management

With their low density and high porosity, aerogels are widely used as supporting frameworks for phase change materials (PCMs). However, the host-guest solid-liquid phase-change systems often encounter difficulties in optimizing the balance between mechanical properties and thermal energy storage performance, the intrinsic advantages of aerogels not being fully realized. Herein, an aerogel-functionalization-PCM strategy, a completely converse route compared to traditional aerogel-filling-PCM method, toward lightweight, flexible PCM for robust thermal management is developed. As a proof of concept, silica aerogel particles (SAPs) as functional components are added to a polyvinyl alcohol-polyethylene glycol network to produce composite PCMs. The addition of SAP reduces the composite PCM's latent heat by 25% but significantly decreases the heating rate by 190% and enhances thermal insulation by 147%, achieving a 28 °C temperature drop at 80 °C. This work provides a fresh perspective on the design of flexible and thermally robust PCMs and demonstrates the feasibility of enhancing thermal protection under reduced latent heat conditions.