Development of sustainable composite PCMs using bio-derived activated carbon hybrid matrices for enhanced thermal energy storage efficiency

Abstract

The enhancement of heat storage and conversion efficiency in phase change materials (PCMs) often involves incorporating supporting materials to address the main obstacles, such as leakage issues and low heat transfer rates, associated with PCMs. However, as these supporting materials come from various sources and synthesis methods, there is a growing emphasis on developing renewable and sustainable PCM composites. This study introduces a novel approach by designing cost-effective and eco-friendly AC-hybrids using apricot kernel shell-derived activated carbon (AKAC) and carbon nanofibers (CF). The innovative combination of AKAC and CF effectively enhances both thermal conductivity and shape stability, offering a sustainable solution to overcome the inherent limitations of PCMs. AKAC-CF hybrids with 3 and 5 wt% CF ratios exhibited n-eicosane (n-Eic) PCM adsorption rates of 78 % and 80 wt%, respectively, surpassing the 75 % loading rate achieved by pristine AKAC alone. The resulting AKAC-CF-n-Eic composite, loaded with 80 % n-Eic, displayed a melting point of 34.40 °C and an enthalpy of 189.20 J/g. Remarkably, the thermal conductivity of composite PCMs supported by AKAC-CF hybrids exhibited significant enhancement compared to that of AKAC/n-Eic. This improvement in thermal conductivity was further validated through infrared thermal imaging tests. Overall, the advancement of AKAC-CF hybrids as supporter matrices and enhancers of thermal conductivity for n-Eic holds immense potential across a wide range of thermal management applications.