Constructing phase boundary in AgNbO₃ antiferroelectrics: pathway simultaneously achieving high energy density and...

Area of Science:

• Materials Science
• Solid-State Physics
• Energy Storage

Background:

• High energy storage density and efficiency are critical for dielectric capacitors in pulsed power applications.
• Current lead-free dielectric materials struggle to optimize both energy storage density and efficiency simultaneously.
• Developing advanced lead-free dielectrics is essential for next-generation power electronic systems.

Purpose of the Study:

• To develop a lead-free dielectric material with simultaneously high energy storage density and efficiency.
• To investigate the (1-x)AgNbO3-xAgTaO3 solid solution system for advanced energy storage applications.
• To understand the structure-property relationships governing energy storage performance in these materials.

Main Methods:

• Synthesis and characterization of (1-x)AgNbO3-xAgTaO3 solid solutions.
• Fabrication and testing of dielectric capacitors based on the developed materials.
• Utilizing scanning transmission electron microscopy (STEM) and synchrotron X-ray diffraction (XRD) for structural analysis.

Main Results:

• Achieved a high recoverable energy storage density (Wrec) of 6.3 J cm⁻³ with an efficiency (η) of 90% at room temperature.
• Demonstrated excellent energy storage stability over a wide temperature range (20–150 °C).
• Confirmed exceptional cycling reliability up to 10⁶ cycles.

Conclusions:

• The (1-x)AgNbO3-xAgTaO3 solid solution system offers a promising lead-free dielectric material for high-power energy storage.
• The observed performance is attributed to the unique relaxor antiferroelectric properties arising from local structure heterogeneity and antiferroelectric ordering.
• This study provides a valuable framework for designing lead-free dielectrics for demanding energy storage applications.