Giant electrocaloric cooling in flexible BSZT/Terpolymer composites enabled by interfacial polarization and relaxor ferroelectric synergy

With increasing global concerns about energy efficiency and environmental protection, conventional refrigeration technologies face significant challenges. The electrocaloric effect (ECE), as a solid-state and eco-friendly refrigeration technology, has emerged as a research hotspot for next-generation cooling solutions due to its performance controllability and broad applicability. A critical challenge lies in developing materials that exhibit large temperature change under low electric field. In this study, we designed a flexible composite film with remarkable electrocaloric capability by integrating BSZT-based relaxor ferroelectric fillers into a ternary copolymer matrix P(VDF-TrFE-CFE). Experimental results demonstrate that the incorporation of BSZT fillers significantly enhances the dielectric response and polarization intensity of the composites through interfacial polarization effect. Under a moderate electric field of 75 MV/m, the composite achieves a prominent adiabatic temperature change of 11.2 K, which is ∼2.7 times of the pure polymer matrix (ΔT = 4.09 K). This work provides a novel material solution for green refrigeration technology, particularly promising for applications in portable and wearable devices.