Simultaneously achieved high energy density and efficiency in (1−x)BaZr0.2Ti0.8O3−xBi0.5Na0.5TiO3 thin films with good stability via amorphous-structure engineering.

Dielectric film capacitors are widely studied in recent years owing to their advanced power density and excellent mechanical and thermal stability. Despite the fact that extensive research has been done, the energy storage density still needs to be further improved. Herein, the highly polarized phase and amorphous phase are introduced into barium zirconate titanate simultaneously by the sol–gel method to fabricate (1−x)BaZr_0.2Ti_0.8O₃−xBi_0.5Na_0.5TiO₃ ((1−x)BZT−xNBT) amorphous films, researching the impact of amorphous phase and NBT levels on microstructure, energy storage, and dielectric properties of the films systematically. This material can generate a giant recoverable energy density of 86.35 J cm⁻³ and a great energy efficiency of 89.2% when x = 0.10, showing great thermal stability in energy storage property and dielectric property at 20–200 °C and excellent cycling reliability up to 10⁵ cycles, which indicate the potential of 0.9BZT–0.1NBT film in the energy storage field. More importantly, there is no research on BZT-NBT films in the published literatures up to now. This work verifies the feasibility of this system in energy storage films and provides a new avenue to design lead-free dielectric materials. [ABSTRACT FROM AUTHOR]