High Energy-Storage Capacity in Lead-Free Relaxor Ferroelectric Ceramics with a Simple Chemical Composition Via Synergistic Design

Dielectric energy storage ceramics with both superior energy storage performance (ESP) and simple chemical compositions are highly in demand for dielectric capacitors practical applications. However, advancing excellent ESP commonly demands highly complex chemical components, which is a challenging task that remains unresolved. Here, via integrating the component engineering and process engineering, we achieve substantially improved energy storage density Wrec (∼9.21 J/cm3) and efficiency η (∼85.4%)under 940 kV/cm in SrTiO3-based ceramic with a simple chemical composition (two doped elements), showcasing tremendous potential for next-generation energy-storage device. The achieved performance merits are credited to multiple synergy effects: local polar structure concomitant with ultrasmall and highly dynamic polar nano-regions, improved electrical homogeneity, reduced grain size, and suppressed oxygen vacancies. Therefore, our proposed approach offers a design freedom to develop high-performance dielectrics with a simple composition for practical implementations of dielectric capacitors.