Composition and Structure Optimized BiFeO3‐SrTiO3 Lead‐Free Ceramics with Ultrahigh Energy Storage Performance

Dielectric ceramic capacitors have attracted increasing attention as advanced pulsed power devices and modern electronic systems owing to their fast charge/discharge speed and high power density. However, it is challenging to meet the urgent needs of lead‐free ceramics with superior energy storage performance in practical applications. Herein, a strategy for the composition and structural modification is proposed to overcome the current challenge. The lead‐free ceramics composed of BiFeO3‐SrTiO3 are fabricated. A low hysteresis and high polarization can be achieved via composition optimization. The experimental results and finite element simulations indicate that the two‐step sintering method significantly influences the decrease in the grain size and improvement in the breakdown strength (EBDS). A high EBDS of ≈750 kV cm−1 accompanied by a large maximum polarization (≈40 µC cm−2) and negligible remanent polarization (