Novel BCZT-based ceramics with ultrahigh energy storage efficiency and outstanding high temperature fatigue endurance and stability for practical application

Dielectric ceramic capacitors with superior energy storage efficiency and ability to operate in high temperature environments (T∼200 °C) are urgently needed for practical application. In this study, a relaxor component of Bi(Zn2/3Nb1/3)O3 (BZN) was massively doped into Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) ceramic to improve energy storage properties and ability to operate in high temperature. The massive introduction of Bi(Zn2/3Nb1/3)O3 optimizes dielectric relaxor behavior, enhances bandgap width, refines grain size and improves electrical homogeneity, which can significantly increase breakdown strength (Eb), decrease remanent polarization (Pr) and broaden dielectric constant peak. Here, the 0.75BCZT-0.25BZN ceramic possesses an ultrahigh energy storage efficiency (∼96.8%) with a large recoverable energy density (∼2.39 J/cm3) under a medium applied field (260 kV/cm). In addition, the optimum sample exhibits prominent thermal stability within 20∼200°C and dielectric temperature stability (ΔC/C25°C ≤ ± 15%, −63∼234°C) in accordance with X9R. More critically, the same composition was firstly measured fatigue endurance at 200°C and possesses excellent fatigue stability. The above results demonstrate that the optimum sample has potential for practical application in high temperature environments.