Organic/carbon and organic/carbon-metal composite phase change material for thermoelectric generator: Experimental evaluation

Abstract

Phase change materials (PCMs) are regarded as a promising choice for thermal energy storage and thermal regulation applications owing to their extensive range of operational temperature. Nevertheless, the effective utilization of PCMs is primarily limited by their inadequate thermal conductivity. Present study investigates the efficacy of employing graphene (Gr) mono nanoparticles and graphene-silver (Gr:Ag) hybrid nanoparticles as an approach to enhance thermal features and establish a comparative analysis in energy storage performance of organic phase change material (PCM). The comparative study suggest the addition of 0.8 weight% (wt%) of hybrid Gr:Ag nanoparticles (NPs) enhanced the thermal conductivity of PCM (RT54HC) by 96 %, while 0.8 wt% addition of mono graphene NPs increases thermal conductivity by 83 %. Hybridization of Ag nanoparticle over Gr nanoparticle surface ensures uniform dispersion of nanoparticle into the PCM matrix overcoming the issue of floating in graphene mono nanoparticle and settling in silver nanoparticle. Subsequently, energy storage enthalpy of nanocomposite PCM with 0.8 wt% NPs of Gr and Gr:Ag nanoparticle results in increase in latent heat by 11 % and 8.5 % respectively. Likewise, inclusion of Gr nanoparticles resulted in a decrease in optical transmissibility by 71 %, while Gr:Ag hybrid nanoparticles led to a slightly lower decrease of 65 %. The composites also exhibited a minor alteration in their thermo-physical properties following 500 thermal cycles, thus validating the reliability of prepared nanoparticle enhanced PCMs. Further, hybrid nanocomposite applied in thermoelectric generator (TEG) that produced 425 mV in comparison to base PCM 325 mV. Therefore, the prepared nanocomposites, with their established capabilities, have the potential to make a substantial contribution to the advancement of energy storage requirements in the future.