Superior Energy-Storage Performance in Sandwich-Structured AgNbO₃-Based Ceramics

Area of Science:

• Materials Science
• Solid State Physics
• Ceramics Engineering

Background:

• Antiferroelectric (AFE) ceramics offer high capacitance density for capacitors.
• Limited energy storage in AFE ceramics stems from a trade-off between polarization and breakdown strength.

Purpose of the Study:

• To simultaneously enhance polarization and breakdown strength in AFE ceramics.
• To optimize a sandwich structure for improved energy storage performance.
• To explore the potential of lead-free AFE ceramics for practical applications.

Main Methods:

• Fabrication of a sandwich-structured ceramic using alternate layers of (Ag0.82Bi0.06)NbO3 and (Ag0.70Bi0.10)NbO3.
• Optimization of the layer composition to balance high polarization and high breakdown strength.
• Characterization of energy storage density, efficiency, stability, and discharge properties.

Main Results:

• Achieved a peak recoverable energy storage density (Wrec) of 16.8 J cm⁻³ with 81.3% energy efficiency (η).
• Demonstrated excellent stability across temperatures (30-150 °C), frequencies (1-500 Hz), and cycling (10⁵).
• Recorded a discharge energy density (Wd) of 6.2 J cm⁻³ and a fast discharge time (t0.9) of 120 ns.

Conclusions:

• The optimized sandwich structure effectively overcomes the polarization-breakdown strength limitation in AFE ceramics.
• The developed lead-free AgNbO3-based AFE ceramic exhibits superior energy storage performance and stability.
• This strategy provides a viable route for high-performance lead-free AFE ceramics in pulse power systems.