Application of copper slags in encapsulating high-temperature phase change thermal storage particles

作者：Ye, Chengliang; Zhang, Meijie^*; Yang, Shuang; Mweemba, Stephen; Huang, Ao; Liu, Xing; Zhang, Xiliang

来源：Solar Energy Materials and Solar Cells, 2023, 254: 112257.

DOI：10.1016/j.solmat.2023.112257

• Copper slag
• Thermal energy storage
• Macro encapsulation
• Commercial metal ball
• Double layer shell

Achieving efficient and low-cost preparation of high-temperature phase change materials (HTPCMs) is of great significance to the sustainable development of thermal energy storage (TES) systems. This study reports the successful fabrication of core-shell structure macro capsules using copper slag partial replacement of bauxite in the shell raw material. The commercial solid Al ball was in situ encapsulated by a double-layer ceramic shell with the cavity between the core and the inner shell using a two-step granulating method and heat treatment. Sur-prisingly, the macro capsules with the addition of copper slag in the shell material showed excellent thermal cycle stability and durability at the drastic melting-solidification cycling test up to 500 cycles even under air atmosphere. The addition of copper slag to the shell material of HTPCMs effectively improves the sensible heat storage capacity, thermal conductivity and thermal diffusivity. This can be attributed to the formation of Fe2O3 in the outer layer shell. This research provides a novel idea for the high-value utilization of copper slag to produce HTPCMs and realize the recycling of solid waste resources.