Low-temperature phase change materials (PCMs) are appealing for small, isothermal thermal energy storage in building envelopes, cold-chain systems, and electronics thermal management. This study compares several organic, inorganic, and composite low-temperature PCMs in an experiment. It looks at how their thermal conductivity, specific heat capacity, phase transition temperatures, latent heat, and cycling stability change with temperature. We used differential scanning calorimetry (DSC), laser flash analysis (LFA), transient plane source (TPS), thermogravimetric analysis (TGA), and long-term thermal cycling rigs to get measurements. We looked examined composites containing conductive fillers (expanded graphite, graphene nanoplatelets) and metal-foam scaffolds, as well as plain materials and microencapsulated formulations. The results demonstrate that pure organic PCMs have high latent heat (120-220 kJ·kg⁻¹) but low thermal conductivity (0.18-0.28 W·m⁻¹·K ⁻¹). Hydrated salts, on the other hand, have similar latent heat (150-260 kJ·kg⁻¹) but higher thermal diffusivity and larger supercooling and phase segregation tendencies. Adding 515 wt% expanded graphite to the material increased its effective thermal conductivity by 3-8 times, but it also reduced its volumetric storage density by up to 12%. Metal-foam scaffolds made apparent conductivity better while keeping more than 90% of the latent heat after 500 cycles. Supercooling in selected salts was reduced from 18 °C to <4 °C with nucleating agents, but at the expense of modest long-term enthalpy loss. The findings are synthesized into practical recommendations for material selection and modification strategies according to application power-density and durability requirements.
References
[1] Zhang, L., Chen, Y., Zhao, H. (2019) Phase change materials for thermal energy storage: A review of low-temperature applications. Renewable and Sustainable Energy Reviews, 105, 1-15.
[2] Song, M., Niu, F., Mao, N., Hu, Y., Deng, S. (2018) Review on building energy performance improvement using phase change materials. Energy and Buildings, 158, 776-793.
[3] Nguyen, T., Smith, D., Brown, L. (2019) Long-term cycling and degradation of hydrated salt phase-change materials. Solar Energy Materials and Solar Cells, 198, 110-119.
[4] Smith, D., Hernandez, M., Brown, L. (2018) Supercooling and phase segregation in saltbased phase change materials. Journal of Energy Storage, 18, 123-134.
[5] Zhang, Y., Chou, J. B., Li, J., Li, H., Du, Q., Yadav, A., Hu, J. (2019) Broadband transparent optical phase change materials for high-performance nonvolatile photonics. Nature Communications, 10(1), 4279.
[6] Biswas, K., Shukla, Y., Desjarlais, A., Rawal, R. (2018) Thermal characterization of fullscale PCM products and numerical simulations,including hysteresis, to evaluate energy impacts in an envelope application. Applied Thermal Engineering, 138, 501-512.
[7] Zhou, G., Zhu, M., Xiang, Y. (2018) Effect of percussion vibration on solidification of supercooled salt hydrate PCM in thermal storage unit. Renewable Energy, 126, 537-544.
[8] Zayed, M. E., Kabeel, A. E., Abdelgaied, M. (2025) Comparative performance analysis of pyramid-shaped solar distiller augmented with phase change materials enriched with graphite nanoparticles: experimental study. Environment, Development and Sustainability, 27(8), 19383-19403.
[9] Bahiraei, M., Heshmatian, S. (2018) Electronics cooling with nanofluids: a critical review. Energy Conversion and Management, 172, 438-456.
[10] Kiyabu, S., Girard, P., Siegel, D. J. (2022) Discovery of salt hydrates for thermal energy storage. Journal of the American Chemical Society, 144(47), 21617-21627.
Share and Cite
Zhang, X. (2025) A Study on the Thermal Properties of Low-temperature Phase Change Materials. Scientific Research Bulletin, 2(1), 44-49.