Enhanced dielectric energy storage performance of A-site Ca2+-doped Na0.5Bi0.5TiO3–BaTiO3–BiFeO3 Pb-free ceramics

(1- x ) (0.98Na 0.5 Bi 0.5 TiO 3 –0.01BaTiO 3 –0.01BiFeO 3 )– x CaTiO 3 (NBB- x CT) ceramics were produced using traditional solid-state synthesis methods. The surface morphology , domain structure, and electrical properties of the ceramic samples were systematically studied. In addition, the temperature and frequency stabilities of the NBB-15CT sample at 200 kV/cm were tested. Generally, NBB- x CT ceramics exhibit a typical single perovskite phase structure. The results indicate that the NBB-15CT ceramics showed a high energy density of 3.14 J/cm 3 at 250 kV/cm. The piezoresponse force microscopy (PFM) results showed that the addition of CT broke the macrodomains of the 0.98Na 0.5 Bi 0.5 TiO 3 -0.01BaTiO 3 -0.01BiFeO 3 ceramic and helped to form nanodomains, leading to an improved energy storage performance. The above performance indicates that the specimens possess very good temperature-and frequency-dependent energy storage performances at 30–150 °C and 1–100 Hz. Moreover, the electric energy storage and release in the NBB-15CT ceramic indicated that the power density could reach 55.30 MV/cm 3 at 180 kV/cm. Therefore, the NBB-15CT ceramic is a promising material for electrical capacitors.