Improved Energy Storage Performance at the Phase Boundary in Batio3-Based Thin Film Capacitors

Abstract

Relaxor ferroelectric thin films have been widely studied for applications in miniaturized advanced pulsed power devices due to their fast charging and discharging rates and very fine polarized electric field hysteresis, which can be designed by incorporating paraelectric components into the ferroelectrics. In this work, lead-free BaTiO3-based relaxor ferroelectric thin films are achieved by formulating solid solutions of ferroelectric BaTiO3 with the paraelectric BaZrO3. The optimized energy storage performance is achieved at the ferroelectric-relaxor ferroelectric phase boundary in the BaZr0.3Ti0.7O3 thin films with an improved recoverable energy storage density of 58.6 J/cm3 and an energy storage efficiency of 71% due to the increased maximum polarization. In addition, frequency-insensitive stability from 100 Hz to 10 kHz, long-term fatigue resistance up to 107 switching cycles, and high-temperature stability in the range of 20 °C to 100 °C are achieved. The work offers a good strategy via creating a phase boundary for improving the energy storage performance in the BaTiO3-based relaxor ferroelectric thin films for advanced energy storage dielectric capacitors.

Keywords: phase boundary, sol-gel, Thin Film, relaxor ferroelectric, Energy storage