Achieved excellent energy storage properties and ultrahigh power density of Ba0.85Ca0.15Zr0.1Ti0.9O3 lead-free ceramics modified by Bi(Mg0.5Hf0.5)O3

Abstract

Herein, novel binary systems of (1-x)Ba0.85Ca0.15Zr0.1Ti0.9O3-xBi(Mg0.5Hf0.5)O3 ((1-x)BCZT-xBMH, x = 0.00 ∼ 0.30) were fabricated based on a collaborative optimization strategy of compositional modulation and nano-domain. All the samples have a pure perovskite structure with a compact microstructure devoid of pores. Interestingly, an excellent recoverable energy density (Wrec ∼ 3.29 J/cm3) and high efficiency (η ∼ 90%) were achieved in 0.75BCZT-0.25BMH ceramics under 305 kV/cm. The improved energy storage performances (ESP) could be attributed to the fact that the introduction of Bi(Mg0.5Hf0.5)O3 increases the band gap, decreases the leakage current and grain size, in particular, frustrates the long range ferroelectric order, leading to the formation of the polar nanoregions (PNRs). Moreover, an ultrahigh power density (∼133.76 MW/cm3), an ultrafast discharge time (∼98 ns), an high frequency stability (1–103 Hz), fatigue resistance (×104 cycles), and good temperature stability (20–120 °C) can be concurrently realized in the optimized ceramics. These results demonstrate that the environmentally friendly 0.75BCZT-0.25BMH lead-free ceramics are a potential candidate for dielectric energy storage devices.