Different dimensional nanoadditives for thermal conductivity enhancement of phase change materials: Fundamentals and applications

Thermal energy storage technologies based on phase change materials (PCM) have been increasingly studied because of their superb regulation of thermal energy and their recent increases in efficient energy utilization. However, the low thermal conductivity of pure PCM immensely restricts their use in some applications such as the thermal management of devices and wearable textiles. Adding highly thermal conductive nanoadditives to PCM is widely accepted as a highly effective strategy to enhance the thermal conductivity of PCM. In this review, a comprehensive summary of the recent advances in enhancing thermal conductivity of PCM based on different dimensional nanoadditives is proposed, including zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) nanoadditives along with hybrid nanoadditives. We emphasize the fundamental thermal mechanisms: phonon transport, interfacial thermal resistance, thermal conductive architectures, and thermal conductivity. Furthermore, we systematically compare the traits and differences of different dimensional nanoadditives and their construction of thermally conductive pathways on the thermal conductivity enhancement of PCM. Potential applications in different fields for PCM with enhanced thermal conductivity are also presented. Finally, we outline the main advances, challenges and outlooks for enhancing the thermal conductivity of PCM.