Enhanced energy storage performance and thermal stability in relaxor ferroelectric (1‐x)BiFeO3‐x(0.85BaTiO3‐0.15Bi(Sn0.5Zn0.5)O3) ceramics

Lead‐free (1‐x)BiFeO3‐x(0.85BaTiO3‐0.15Bi(Sn0.5Zn0.5)O3) [(1‐x)BF‐x(BT‐BSZ), x=0.45‐0.7] ceramic samples were prepared by solid phase sintering. It is revealed that the pure single‐phase perovskite structure can be obtained in samples with x ≥ 0.6. With increasing x, the measured ferroelectric hysteresis loop becomes gradually slimmed in accompanying with reduced remnant polarization, and a clear ferroelectric‐relaxor transition at x = 0.65 is identified. Furthermore, the measured electric breakdown strength can be significantly enhanced with increasing x, and the optimal energy storage performance is achieved at x = 0.65, characterized by the recoverable energy storage density up to ≈3.06 J/cm3 and energy storage efficiency as high as ≈92 %. Excellent temperature stability (25°C–110°C) and fatigue endurance (>105 cycles) for energy storage are demonstrated. Our results suggest that the BF‐based relaxor ceramics can be tailored for promising applications in high energy storage devices. An optimal energy storage performance with high Wre ≈ 3.06 J/cm3 and high η ≈ 92% was obtained at x = 0.65 sample. Moreover, the energy storage performance could reach 105 cycles of fatigue endurance.