Medium-temperature promising candidate thermal management materials: Interfacial passivation via TTA ligands enhances thermal cyclability of copper foam/Bi-In phase change materials

Metal-based phase change composites (MPCMs) with high thermal conductivity and energy density are promising candidates for advanced thermal management applications, especially in medium-temperature. However, interfacial reactions between the metal framework and the encapsulated metal phase change material frequently compromise their stability. In this study, we developed a stabilized copper foam(CF)/bismuth‑indium(Bi In) MPCM through vacuum pressurized impregnation process and interfacial modification with 2-thenoyltrifluoroacetone (TTA). The porous CF was functionalized with the chelating ligand, TTA, forming a passivation layer that effectively suppresses the interfacial formation of copper‑indium intermetallic compounds (IMCs). The Bi In alloy was then infused into the foam structure using a vacuum pressurized impregnation process, yielding a uniform composite with exceptional properties, including high thermal conductivity (37.92 W/m·K), substantial latent heat (357.44 J/cm 3 ), and excellent latent heat retention (91.23 % after 200 cycles). SEM and XRD revealed that the IMC growth rate in TTA-modified samples significantly slowed during thermal aging. This work introduces a novel strategy for fabricating high-performance MPCM's and paves the way for broader applications in industrial waste heat recovery, thermal management of high-power electronics, and thermal cushioning in vehicle components.