Novel Latent Heat Storage Systems Based on Liquid Metal Matrices with Suspended Phase Change Material Microparticles

Phase change materials (PCMs) are considered useful toolsfor efficientthermal management and thermal energy utilization in various applicationfields. In this study, a colloidal PCM-in-liquid metal (LM) systemis demonstrated as a novel platform composite with excellent latentheat storage capability, high thermal and electrical conductivities,and unique viscoelastic properties. In the proposed formulation, eutecticGa-In is utilized as a high-thermal-conductivity and high-fluidityliquid matrix in which paraffinic PCM microparticles with varioussolid-liquid phase transition temperatures are suspended asfillers. Good compatibility between the fillers and matrix is achievedby the nanosized inorganic oxides (titania) adsorbed at the filler-matrixinterface; thus, the composite is produced via simple vortex mixingwithout tedious pre- or post-processing. The composite shows uniquetrade-off effects among various properties, i.e., elastic modulus,yield stress, density, thermal conductivity, and melting or crystallizationenthalpy, which can be easily controlled by varying the contents ofthe suspended fillers. A Joule heating device incorporating the compositeexhibits improved electrothermal performance owing to the synergybetween the high electrical conductivity and latent heat storage capabilityof the composite. The proposed platform may be exploited for the rationaldesign and facile manufacture of high-performance form-factor-freelatent heat storage systems for various potential applications suchas battery thermal management and flexible heaters.