Synergistic optimization of barium titanate-based ferroelectrics for enhanced energy storage performance

Barium titanate (BT) ferroelectric materials have garnered significant interest in pulse dielectric capacitor devices due to their remarkable chemical stability and exceptional electrical performance. However, their inferior energy-storage performance (ESP), characterized by inadequate breakdown strength and high energy storage loss, has hindered their further advancement in applications. To address this challenge, we adopt a synergistic optimization strategy combining composition design with chemical substitution and microstructure engineering through the viscous polymer process (VPP) to develop an eco-friendly system, denoted as (1–x)[0.65BaTiO₃-0.35(Sr_0.7Bi_0.2)TiO₃]-xBi(Mg_2/3Nb_1/3)O₃ (abbreviated as BS-xBMN). This deliberate modification enhances polarization by leveraging the hybridization of the 6 s orbitals of Bi³⁺ ions with the 2p orbitals of O²⁻ ions. By adjusting the BMN content to regulate relaxor ferroelectric characteristics and field-induced polarization, we promote the formation of polar nanoregions and microstructural heterogeneity, ultimately enhancing ESP and improving the thermal stability of the materials. In the BS-0.05BMN ceramics fabricated by the VPP, we simultaneously achieve a large recoverable ES density of 5.29 J/cm³ and a prime energy storage efficiency of 95.3% under the E-field of 520 kV/cm, along with reliable temperature applicability within 30−150 °C. These results highlight the potential of BT-based materials for energy storage and provide guidance for future research endeavors.