Effect of carbon-based hybrid nano-fillers on the thermal conductivity of PCM composites

PCMs show great promise as thermal energy storage (TES) medium; however, their low thermal conductivity presents a major bottleneck for their potential application. Enhancement of the thermal conductivity of a paraffin based PCM material using GNP in combination with CNF, CNTs and TRG was investigated in this work. SEM was used to qualitatively assess the dispersion & distribution of the hybrid-nanofillers. DSC was used to determine the melting temperature, thermal capacity and latent heat, whereas thermal conductivity was measured using Hot Disk TPS Thermal Conductivity Instrument (TPS2500S). An overall increase by 143%, 158% and 174% in thermal conductivity and 179%, 193% and 214% in thermal diffusivity was observed for 2 wt.% hybrid loading of TRG, CNT and CNF respectively (pure PCM as ref.). Furthermore, the contribution of the CNF and CNT hybrid-fillers was evaluated to increase the composite PCM thermal conductivity by 122% & 110%, and diffusivity by 117% & 105% respectively (10%-GNP as ref.).