Radial assembly of graphene nanoplates via ice-template method to construct 3D thermally conductive phase change materials

Abstract

Phase change material (PCM) with the capacity to store and release substantial thermal energy, has drawn significant attention. However, its large-scale application is still hindered by inadequate thermal management capacity and unsatisfactory thermal conductivity. In this study, graphene nanoplates were assembled into a 3D thermally conductive scaffold using a specialized ice template method. By virtue of the unique growth of ice crystals in radial pattern, a series of multidirectional thermal conduction pathways were successfully constructed within PCM, which has provided microscopically interconnected pathways for thermal transport. Consequently, a remarkable 5.2-fold increment in thermal conductivity (1.365 W m−1 K−1) in comparison to pure paraffin was achieved by incorporating a mere 6 vol% of GNP, which therefore enables excellent thermal cycling stability, remarkable latent heat storage capacity exceeding 175 J/g, together with leak-proof properties even under extended high-temperature conditions. Moreover, the solar-to-thermal energy storage efficiency is up to 85.8 % due to its efficient photothermal effect. This work presents an innovative approach to design PCMs with enhanced thermal conductivity and photothermal efficiency, offering promising applications in advanced thermal storage.