Enhanced energy storage properties of Sm(Mg0.5Ti0.5)O3 modified (Bi0.5Na0.5)0.7Sr0.3TiO3 relaxor ferroelectric ceramics

Developing high performance and pollution-free energy storage devices is crucial for the development of the energy industry. The Sm(Mg0.5Ti0.5)O3-modified (Bi0.5Na0.5)0.7Sr0.3TiO3 ((1-x)BNST–xSMT, x = 0.00–0.15)) relaxor ceramics were synthesized by using a traditional solid-state sintering method. The phase structure, microstructure, dielectric spectrum, and energy storage properties were studied. The x = 0.10 sample obtained an energy storage density of 4.33 J/cm3 under an electric field of 290 kV/cm, while the energy storage efficiency reached 80 %. In addition, the variation of energy storage density remains within ±4 % and the energy storage efficiency is above 80 % at a frequency of 1–100 Hz and a temperature of 25–120 °C, respectively, indicating that the x = 0.10 sample has good stability in both temperature and frequency. The energy storage decreases slightly with increasing temperature and frequency, which originates from the migration of intrinsic charge carriers and the weakening of the interaction force between cations and anions. In addition, the x = 0.10 sample exhibits good fatigue resistance, with little change in the ferroelectric loop after 105 cycles. This performance advantage indicates that the (1-x)BNST-xSMT ceramic systems have great potential in the field of high energy storage.