Microstructure-engineered electrocaloric P(VDF-TrFE-CFE) terpolymer-based nanocomposites with enhanced interfacial coupling for rapid thermal switching

Electrocaloric (EC) cooling represents a promising solid-state approach for next-generation thermal management. However, achieving substantial temperature modulation remains a challenge due to intrinsic material limitations and inefficient energy conversion. Herein, we focus on microstructure regulation to enhance thermal conductivity and EC performance. A hydroxyl-functionalized Ba0.63Sr0.37Zr0.01(Ti0.999Mn0.001)0.99O3 (BSZMT-OH) and h-BNNS-OH composite was designed, with enhanced interfacial hydrogen bonding to optimize electric field response in a P(VDF-TrFE-CFE) matrix. Finite element analysis (FEA) and piezo response force microscopy (PFM) reveal strengthened interfacial coupling, which facilitates rapid domain switching kinetics by amplifying tetragonal P4mm phase responses. These enhancements yield a peak EC temperature change (ΔT) of 1.59 K under a low electric field of 40 MV/m in the optimized 6% BSZMT-OH@4 h-BNNS-OH (6@4BNNS) composite. Integrated into a double-layer four-section electrocaloric cooling (DL 4 EC) device, it cools from 70 to 23 °C in 23 s, outperforming water cooling. Our findings offer insights into EC mechanisms and present a high-performance thermal management strategy.