Outstanding comprehensive energy storage performance in lead-free BiFeO3-based relaxor ferroelectric ceramics by multiple optimization design

Abstract

Lead-free ceramic-based dielectric capacitors with high-performance energy storage properties have become an emerging issue recently as a result of the applications in high-power and/or pulsed-power technologies. However, the trade-off between various parameters, such as maximum polarization Pmax, remnant polarization Pr and dielectric breakdown strength Eb, restricts the further improvement of the energy storage properties of dielectric ceramics. Herein, a synergistic optimization strategy via simultaneous enhancement of Pmax and Eb and reduction of Pr is adopted to achieve outstanding energy storage properties for Bi0.9La0.1FeO3-Ba0.7Sr0.3TiO3NaNb0.85Ta0.15O3 relaxor ferroelectric ceramics, characterized by an ultrahigh recoverable energy density Wrec of 15.9 J/cm3 and high efficiency η of 87.7%. The inborn gene of BiFeO3-based materials results in high Pmax and the improved relaxor behavior gives rise to a small Pr value. In Particular, a very large value for Eb is obtained by tailoring multiple intrinsic and extrinsic factors. These results demonstrate the reliability and feasibility of the multiple optimization strategy proposed in this work to develop novel dielectric ceramics for advanced energy storage applications.