Multifunctional Flexible Ferroelectric Thin Films with Large Electrocaloric Effect and High Energy Storage Performance

作者：Chengwen Bin, Xu Hou, Zeqing Yu, Luocheng Liao, Han Yang, Yunya Liu, Jie Wang · 发表于：ACS Applied Materials & Interfaces · 年份：2024 · DOI：10.1021/acsami.3c14630 · 被引用次数：23 · 研究领域：Ferroelectric and Piezoelectric Materials、Dielectric materials and actuators、Multiferroics and related materials

Flexible ferroelectric films with high polarization hold great promise for energy storage and electrocaloric (EC) refrigeration. Herein, we fabricate a lead-free Mn-modified 0.75 Bi(Mg 0.5 Ti 0.5 )O 3 –0.25 BaTiO 3 (BMT–BTO) thin film based on a flexible mica substrate. Excellent EC performance with maximum adiabatic temperature change (Δ T ∼23.5 K) and isothermal entropy change (Δ S ∼33.1 J K –1 kg –1 ) is achieved in the flexible BMT–BTO film, which is attributed to the local structural transition and lattice disorder near 90 °C. Meanwhile, a good energy storage density of ∼70.6 J cm –3 and a quite high efficiency of ∼82% are realized in the same ferroelectric film, accompanied by excellent stability of frequency and electric fatigue (500–10 kHz and 10 8 cycles). Furthermore, there is no apparent variation in performance under different bending strains. These prominent properties indicate that the multifunctional BMT–BTO ferroelectric film is a promising candidate for applications of flexible energy storage and EC refrigeration.