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

Area of Science:

• Materials Science
• Solid State Physics
• Nanotechnology

Background:

• Flexible ferroelectric films are crucial for next-generation energy storage and electrocaloric (EC) refrigeration.
• Developing lead-free materials with high performance and stability is a key challenge.

Purpose of the Study:

• To fabricate and characterize a lead-free Mn-modified Bi(Mg0.5Ti0.5)O3-BaTiO3 (BMT-BTO) thin film on a flexible mica substrate.
• To evaluate its potential for energy storage and EC refrigeration applications.

Main Methods:

• Fabrication of a lead-free Mn-modified 0.75 Bi(Mg0.5Ti0.5)O3-0.25 BaTiO3 (BMT-BTO) thin film on a flexible mica substrate.
• Measurement of electrocaloric performance (adiabatic temperature and isothermal entropy changes).
• Assessment of energy storage density, efficiency, frequency, and electric fatigue stability.

Main Results:

• Achieved excellent electrocaloric performance with a maximum adiabatic temperature change (ΔT) of ~23.5 K and isothermal entropy change (ΔS) of ~33.1 J K⁻¹ kg⁻¹.
• Realized a high energy storage density of ~70.6 J cm⁻³ with an efficiency of ~82%.
• Demonstrated excellent stability over a wide frequency range (500-10 kHz), 10⁸ cycles of electric fatigue, and under various bending strains.

Conclusions:

• The flexible BMT-BTO ferroelectric film exhibits outstanding multifunctional properties for energy storage and EC refrigeration.
• Its robust performance under mechanical strain makes it a promising candidate for flexible electronic devices.