High Energy Storage Performance under Moderate Electric Field in Fine-Grain Bi_0.5Na_0.5TiO₃-Based Ceramics

Area of Science:

• Materials Science
• Solid State Physics
• Energy Storage

Background:

• Ceramic dielectrics are crucial for pulsed-power devices due to high power density.
• Current high energy density capacitors require extremely high electric breakdown strength (>500 kV/cm).

Purpose of the Study:

• To develop a lead-free dielectric ceramic with high recoverable energy density at a moderate electric field.
• To investigate the relationship between material structure and energy storage performance.

Main Methods:

• Preparation of a relaxor ferroelectric ceramic based on Bi_0.5Na_0.5TiO₃-NaNbO₃-BaZrO₃.
• Characterization of energy storage properties, including recoverable energy density (W_rec) and efficiency (η).
• Analysis of electric breakdown strength (E_b) and polarization difference (ΔP).

Main Results:

• Achieved a high W_rec of 7.7 J/cm³ and η of 87.3% at 450 kV/cm.
• Demonstrated a large ΔP of 39.4 μC/cm² and E_b of 464 kV/cm.
• Exhibited excellent reliability across frequency, fatigue, and temperature ranges.

Conclusions:

• The developed Bi_0.5Na_0.5TiO₃-NaNbO₃-BaZrO₃ ceramic shows significant potential for high-capacitive energy storage applications.
• Enhanced ergodic relaxor state and reduced grain size contribute to superior performance.
• This work provides a pathway for advancing lead-free dielectric ceramics.