(Na0.5Bi0.5)0.7Sr0.3TiO3 modified by Bi(Mg2/3Nb1/3)O3 ceramics with high energy-storage properties and an ultrafast discharge rate†
The design of ceramic dielectrics with high energy-storage properties and outstanding temperature stability is an important but challenging topic in advanced electronic and electrical power systems. Here, we utilized a strategy to achieve synergistic enhancement of energy density and energy efficiency in the (1 − x)(Na0.5Bi0.5)0.7Sr0.3TiO3–xBi(Mg2/3Nb1/3)O3 systems based on refined grain size and the introduction of Bi3+'s lone pair electron 6s2 configuration, respectively. As a result, a giant discharge energy density of 3.45 J cm−3 and a high energy efficiency of 88.01% were simultaneously achieved in the 0.85NBST–0.15BMN ceramic, which precede those of recently reported lead-free dielectric ceramic materials. Meanwhile, excellent temperature (30–150 °C) and frequency (1–100 Hz) stability were also observed at 200 kV cm−1. Moreover, an outstanding power density (PD) of 38.47 MW cm−3 and an ultrafast discharge rate (t0.9) of 52.8 ns were also achieved in the 0.85NBST–0.15BMN ceramic at 120 kV cm−1. These results may provide a feasible approach to develop more NBST-based lead-free ceramics with vastly improved energy-storage properties.