Design of Lead-Free Films with High Energy Storage Performance via Inserting a Single Perovskite into Bi4Ti3O12 *

We report a distinctive way for designing lead-free films with high energy storage performance. By inserting different single perovskite cells into Bi 4 Ti 3 O 12 , P – E hysteresis loops present larger maximum polarization, higher breakdown strength and smaller slim-shaped area. We prepared 0.15Bi 7 Fe 3 Ti 3 O 21 -0.5Bi 4 Sr 3 Ti 6 O 21 -0.35Bi 4 Ba 3 Ti 6 O 21 solid solution ferroelectric films employing the sol-gel method, and obtained high energy storage density of 132.5 J/cm 3 and efficiency of 78.6% while maintaining large maximum polarization of 112.3 μ C/cm 2 and a high breakdown electric field of 3700 kV/cm. Moreover, the energy storage density and efficiency exhibit stability over the temperature range from 20 °C to 125 °C, and anti-fatigue stability maintains up to 10 8 cycles. The films with a simple preparation method and high energy storage performance are likely to become candidates for high-performance energy storage materials.