Analysis on the Improvement of Thermal Performance of Phase Change Material Ba (OH)₂·8H₂O

Benefitting from the characteristics of a high latent heat capacity and stable phase change behavior, phase change materials have widely received concerns in the field of thermodynamic management. Ba(OH)₂·8H₂O is an ideal phase change material (PCM) in the mid-to-low temperature range, but its large-scale application is still limited by severe supercooling during the nucleation process. In this paper, the experimental analysis and comparison are performed via an Edisonian approach, where Ba(OH)₂·8H₂O is adopted as an original substrate; BaCO₃, CaCl₂, NaCl, KH₂PO₄, and NaOH are selected as nucleating agents; and graphite is used as a heat-conducting agent. The results show that Ba(OH)₂·8H₂O containing 1.2% BaCO₃ and 0.2% graphite powder has the best performance. Compared with pure Ba(OH)₂·8H₂O, the supercooling degree is reduced to less than 1 °C, the phase change latent heat duration is extended, and the thermal conductivity is significantly improved. Therefore, this study not only provides a reference for the application of Ba(OH)₂·8H₂O, but can also be used as a guidance for other material modifications.