Realization of temperature insensitive high energy storage performance via introducing NaNbO3 into NBT-KBT system

Abstract The development of lead-free dielectric ceramics with temperature insensitive high discharge energy density (Wdis) and high energy efficiency (η) are highly demanded for the practical applications in energy storage capacitors. In this work, we have designed and fabricated the NaNbO3 modified Na0.5Bi0.5TiO3–K0.5Bi0.5TiO3 (NBT-KBT-xNN) relaxor ferroelectrics. The addition of metastable antiferroelectric NN into the NBT-KBT matrix leads to enhanced relaxor behavior and improved breakdown strength. As a result, the x = 0.4NN specimen not only showed optimal integrated energy storage properties with a large Wdis of 1.7 J/cm3 and η of 90% under a moderate electric field of 150 kV/cm, but also exhibited superior temperature stability with the variation of Wdis within ±15% and η more than 80% from −50 °C to 150 °C. All these properties indicate that NN modified NBT-KBT ceramic was a promising candidate for the practical application of energy storage capacitors.