Phase-change materials (PCMs) are particularly attractive for latent heat storage because they provide a high energy storage density at a constant temperature, which corresponds to the phase transition temperature of the material. Various techniques have been introduced to enhance the thermal conductivity of PCMs. Expanded graphite (EG) is a common thermal enhancer because of its high thermal conductivity, low density, and chemical inertness. This paper provides a brief introduction of several common techniques for heat transfer enhancement and EG preparation. The present review focuses on studies that examined the preparation and characterization of EG/PCM composites, as well as the simulations and applications of EG/PCM composites in thermal management and thermal energy storage systems. Solution, melt-blending, impregnation, and compression methods are used to prepare the binary system which only contains PCMs and EG. Melt-blending, hot-pressing, impregnation, polymerization, sol-gel, and piercing-solidifying incuber methods are used to prepare the ternary system, which contains PCMs, EG, and matrix. The simulation and application data confirm that EG has obvious heat transfer reinforcement effects in thermal management and thermal energy storage systems.

Xianglei Wang, Yanfang Shi, Xuedong Zhai, Buhe Dong, Yunfei Wang, Ruifeng Wang, Shu Sun, Yupeng Hua. Review on heat transfer enhancement of phase-change materials using expanded graphite for thermal energy storage and thermal management . Academic Journal of Engineering and Technology Science (2021) Vol. 4 Issue 1: 26-61. https://doi.org/10.25236/AJETS.2021.040105.

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