Three-dimensional hybrid carbon nanocomposite-based intelligent composite phase change material with leakage resistance, low electrical resistivity, and high latent heat

The development of shape-stabilized composite phase change materials (PCMs) is critical for realization of efficient thermal energy management systems and sustainable energy utilization. Herein, we designed an intelligent, multifunctional, organic composite PCMs with a three-dimensional (3D) hybrid nanocomposite and n-pentadecane. The 3D hybrid material was designed via integration of exfoliated graphene nanoplatelets (xGnP) and multiwalled carbon nanotubes (CNTs). The hybrid nanocomposite exploited the distinctive attributes and synergistic effect of each the supporting component for the well-designed composite PCMs to demonstrate high physical and thermochemical responses. The obtained composite PCM presented a high loading ratio of 82.7% and latent heat of 150.9 ± 0.9 J/g (which is 36% higher than that of the pristine xGnP-supported PCMs) owing to favorable space availability for phase change transformation with the aid of the CNTs skeleton. Moreover, the composite exhibited reduced supercooling (56.6% lower than that of CNTs-supported n-alkane), high leakage resistance capability, and thermal stability performance. The composite PCMs can also enable realization of a thermoelectric conversion system (lower than 10¹ Ω m resistivity, which is a reduction of more than six orders of magnitude compared with pristine n-alkane) and exhibit high thermal diffusivity (up to 3.707 mm²/s), indicating several practical applications thereof.