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 advantagesin therealm of energy conversion and storage due to their capacity to absorband release thermal energy, high energy density, and consistent phasechange temperature. Nevertheless, several drawbacks, including theissue of leakage during solid-liquid phase transition, inadequatesolar absorption capabilities, and low thermal and electrical conductivity,limit the advancement of PCMs. Although substantial efforts have beendirected toward constructing composite PCMs based on three-dimensional(3D) carriers, their practical application in energy conversion necessitatesfurther investigation. In this study, we have successfully fabricateda lightweight composite PCM without liquid phase leakage for addressingthe requirements for high enthalpy and solar-thermal energy conversionand storage. By utilizing a combination of melamine foam (MF), graphenenanoplatelets (GNP), and carbon nanotubes (CNT) as the supportingframework, along with octadecane as the core PCM, we have achievedcomposite PCMs with a loading amount of only 85.8% that exhibit acomparable phase transition enthalpy to that of pure octadecane. Furthermore,the composite PCMs exhibit minimal alterations in thermal performanceeven after undergoing 350 simulated hot and cold cycles. Additionally,the composites exhibit exceptional abilities in solar-thermal conversionand electrothermal conversion, with photothermal conversion efficiencysurpassing 95%. Consequently, the composite PCMs developed in thisstudy demonstrate significant potential for applications in thermalenergy storage and conversion.