Enhanced large field-induced strain and energy storage properties of Sr0.6La0.2Ba0.1TiO3-modified Bi0.5Na0.5TiO3 relaxor ceramics

Dielectric materials especially relaxor ferroelectrics with giant strain and super-high energy density have received substantial attentions. Bi_0.5Na_0.5TiO₃ (BNT)-based ceramics as one of the typical relaxor ferroelectric materials have been extensively explored for their distinctive performance. Here, lead-free (1?x)Na_0.5Bi_0.5TiO₃–xSr_0.6La_0.2Ba_0.1TiO₃ (BNT–SLBT) ceramics were designed and prepared by the solid-state reaction method. A large strain response of 0.470% and huge piezoelectric strain coefficient of 600 pm/V were achieved in BNT–0.15SLBT relaxor, which were attributed to the relaxor-ferroelectric phase transition under stimulated electric field. The ε_r–T curve shows that with the increase of x content, the phase transition temperature moves to room temperature, which improves the energy storage performance. A super-high recoverable energy density W_rec of 3.18 J/cm³ and η of 82.8% under 250 kV/cm can be achieved in BNT–0.25SLBT ergodic relaxor. Moreover, the charge–discharge properties characterized by a high pulse discharge energy density (0.816 J/cm³), a rapid discharge duration (3 μs) and a power density (2.86 MW/cm³) are also observed in BNT–0.25SLBT ceramic. We provide a method for enhanced BNT-based ceramics with strain and energy storage in drive device or capacitor, facilitating the exploration of ceramic in the future.