Enhanced Energy Storage Performance in Mn-Doped BaTiO₃-Based Epitaxial Thin Films.

Area of Science:

• Materials Science
• Solid State Physics
• Dielectric Materials

Background:

• Lead-free dielectric films are crucial for pulse power capacitors but require improved energy storage.
• Enhancing charge-discharge capabilities and breakdown strength is essential for high-performance applications.

Purpose of the Study:

• To investigate the effects of Mn doping on the microstructure, electrical properties, and energy storage characteristics of 0.84BaTiO3-0.16Bi(Mg0.2Ni0.2Zn0.2Zr0.2Nb0.2)O3-xMn/LaNiO3 heteroepitaxial films.
• To optimize Mn doping concentration for superior energy storage performance.

Main Methods:

• Fabrication of heteroepitaxial films using chemical solution deposition (CSD) technology on SrTiO3 (001) substrates.
• Systematic investigation of Mn doping effects on film microstructure, leakage behavior, and breakdown strength.

Main Results:

• Mn doping refines grain size, improves leakage, and enhances breakdown strength.
• Optimal performance at x=0.01 Mn doping: recoverable energy density (Wrec) of 72.3 J·cm⁻³, efficiency (η) of 72.6%, and breakdown strength (Eb) of 5604 kV·cm⁻¹.
• Excellent temperature stability (-120 to 120 °C) and long-cycle reliability (Wrec fluctuation < 2% after 10⁹ cycles).

Conclusions:

• Mn-doped lead-free dielectric films show significant potential for high-power energy storage applications.
• The optimized film demonstrates excellent energy density, efficiency, and stability, making it a promising candidate material.