Melamine Foam/CNT/Graphene Hybrid Aerogel-Based Phase Change Composites with High Latent Heat Capacity for Solar/Electrothermal Conversion

Phase change materials (PCMs) possess notable advantages in the realm of energy conversion and storage due to their capacity to absorb and release thermal energy, high energy density, and consistent phase change temperature. Nevertheless, several drawbacks, including the issue of leakage during solid–liquid phase transition, inadequate solar absorption capabilities, and low thermal and electrical conductivity, limit the advancement of PCMs. Although substantial efforts have been directed toward constructing composite PCMs based on three-dimensional (3D) carriers, their practical application in energy conversion necessitates further investigation. In this study, we have successfully fabricated a lightweight composite PCM without liquid phase leakage for addressing the requirements for high enthalpy and solar-thermal energy conversion and storage. By utilizing a combination of melamine foam (MF), graphene nanoplatelets (GNP), and carbon nanotubes (CNT) as the supporting framework, along with octadecane as the core PCM, we have achieved composite PCMs with a loading amount of only 85.8% that exhibit a comparable phase transition enthalpy to that of pure octadecane. Furthermore, the composite PCMs exhibit minimal alterations in thermal performance even after undergoing 350 simulated hot and cold cycles. Additionally, the composites exhibit exceptional abilities in solar-thermal conversion and electrothermal conversion, with photothermal conversion efficiency surpassing 95%. Consequently, the composite PCMs developed in this study demonstrate significant potential for applications in thermal energy storage and conversion.