Giant Room-Temperature Electrocaloric Effect of Polymer-Ceramic Composites with Orientated BaSrTiO<sub>3</sub> Nanofibers.

Zou, Kailun; Shao, Cancan; Bai, Peijia; Zhang, Chao; Yang, Ying; Guo, Rundong; Huang, Houbing; Luo, Wei et al. · Nano Lett · 2022

basic_science · Level V

Where this comes from

Abstract

Cooling based on the electrocaloric effect (ECE) is a promising solution to environmental and energy efficiency problems of vapor-compression refrigeration. Ferroelectric polymer-ceramics nanocomposites, integrating high electric breakdown of organic ferroelectrics and large EC strength of ceramics, are attractive EC materials. Here, we tuned the orientation of Ba<sub>0.67</sub>Sr<sub>0.33</sub>TiO<sub>3</sub> nanofibers (BST nfs) in the P(VDF-TrFE-CFE) polymer. When the nfs were aligned parallel to the field, a Δ<i>T</i> of 11.3 K with an EC strength of 0.16 K·m/MV was achieved in the blends. The EC strength not only surpasses advanced nanocomposites but also is comparable to ferroelectric ceramics. The simulation indicates that a significantly higher electric field is concentrated in polymer regions around the ends of the orientated nfs, contributing to easier flipping of polymer chains for large ECE. This work provides a new method to obtain large ECE in composites for next-generation refrigeration.