Highly enhanced discharged energy density and superior cyclic stability of Bi0.5Na0.5TiO3-based ceramics by introducing Sr0.7Ca0.3TiO3 component

The composition-induced phase transition from ferroelectric to relaxor and cycling stability is critical for energy storage application of Bi0.5Na0.5TiO3 (BNT) ceramics. The paraelectric Sr0.7Ca0.3TiO3 (SCT) component is selected to modify the ferroelectric phases of BNT ceramics and improve its energy storage properties. A tiny amount of manganese is used to reduce leakage current. High breakdown field of 210 kV/cm, large recoverable energy density of 2.64 J/cm3, and high power density of 61.89 MW/cm3 are achieved simultaneously in the SCT modified BNT ceramics. Meanwhile, an improved discharged energy density for practical application is obtained within the temperature range of 20–120 °C. By deviating from the critical composition with giant strain, the discharged energy density of 1.11 J/cm3 with excellent stability of cycling performance after 7100 cycles can be achieved. Therefore, the as-proposed solution can solve the ceramic cracking originating from high electric field-induced giant strain, and promote the practical capacitor application.