Thermal energy storage performance of paraffin-based composite phase change materials filled with hexagonal boron nitride nanosheets

An experimental assessment was performed on the thermal energy storage performance of a novel family of paraffin-based composite phase change materials (PCMs) filled with hexagonal boron nitride (h-BN) nanosheets. A series of composite PCM samples were prepared at different loadings (0, 1, 2, 5, and 10 wt.%) of h-BN nanosheets in the absence of any surfactants. The composite PCMs were subjected to a variety of characterization techniques. It was shown that the thermal conductivity of the composite PCMs, in both solid and liquid phases, increases by a factor up to 60% with raising the loading of h-BN nanosheets. The melting/solidification points of the composite PCMs were found to be nearly unvaried upon adding h-BN nanosheets, whereas their latent heat of fusion slightly decreases with the loading. In addition, acceleration of both melting and solidification heat transfer rates, afforded by the increased thermal conductivity of the composite PCMs, was clearly exhibited. The observations suggested that h-BN nanosheets may serve as promising fillers for preparing custom high-conductivity composite PCMs toward thermal energy storage applications.