Optimizing electrical performance of low hysteresis Sr0.7Bi0.2TiO3 energy storage ceramic.

Dielectric capacitors with rapid discharge rates and high power density are the basis for advanced pulsed power systems. Sr 0.7 Bi 0.2 TiO 3 (SBT) is expected to be used in energy storage capacitors owing to the small hysteresis and high energy storage efficiency (η). Nevertheless, the low breakdown strength (BDS) limits the enhancement of energy storage density. This study explores the potential of Ho 2 O 3 -modified SBT to address this limitation. Introducing Ho reduces oxygen vacancies, decreases electrical conductivity, and increases thermal conductivity, thus enhancing BDS. The enhancement mechanism of electrical performance is studied through microscopic morphology analysis, structural refinement and numerical simulation. The Sr 0.7 Bi 0.15 Ho 0.05 TiO 3 exhibits remarkable properties, including ultra-low loss tanδ (0.1 %), ultra-high η (95.8 %), and outstanding thermal, frequency, and cycling stability in energy storage properties. Additionally, Sr 0.7 Bi 0.15 Ho 0.05 TiO 3 possesses a high power density (67.9 MW/cm3) and a rapid discharge rate (0.03 μs). The findings indicate that Sr 0.7 Bi 0.15 Ho 0.05 TiO 3 is a prospective material for energy storage capacitors. [ABSTRACT FROM AUTHOR]