Realizing high comprehensive energy storage performances of BNT-based ceramics for application in pulse power capacitors

Lead-free ceramic capacitors play an important role in electrical energy storage devices because of their ultrafast charge/discharge rates and high power density. However, simultaneously obtaining large energy storage capability, high efficiency and superior temperature stability has been a huge challenge for practical applications of ceramic capacitors. Here, the relaxor ferroelectric (1-x)[0.8Bi0.5Na0.5TiO3-0.2Ba(Zr0.3Ti0.7)O3]-xSr0.7La0.2TiO3 ((1-x)(BNT-BZT)-xSLT) ceramics are prepared through solid-state reaction method to obtain excellent comprehensive energy storage performances. Particularly, high recoverable energy density (Wrec ∼ 2.6 J/cm3) as well as superior efficiency (η ∼ 92.2 %) can be achieved simultaneously under 210 kV/cm with composition of x = 0.3. Meanwhile, the corresponding ceramic shows excellent temperature (20−140 °C), frequency (1−200 Hz) and cycle stabilities (106 st). Additionally, the 0.7(BNT-BZT)-0.3SLT ceramic also displays high power density (PD ∼ 38.8 MW/cm3) and extremely short discharge time (τ0.9 ∼ 0.11 μs). Therefore, this study provides a useful guideline for designing novel BNT-based ceramics with superior comprehensive energy storage performances.