Synthesis and characterizations of SrTiO3 modified BNT-KNN ceramics for energy storage applications

Lead-free (1-x) [0.934BNT-0.07KNN]-x SrTiO3/BNT-KNN-ST ceramics with x = 0, 0.04, 0.08, 0.12 and 0.16 were synthesized in single perovskite phase by conventional solid state reaction route. Effect of SrTiO3 modification on phase, microstructure, dielectric, electric field induced polarization, electric field induced strain and energy-storage properties were investigated and discussed in detail. Dielectric study confirmed relaxor nature with a drastic decrease of T-c with the increase of SrTiO3 content in BNT-KNN-ST system. Saturation polarization, remnant polarization, coercive field (E-c ) and maximum induced strain decreased with the increase of SrTiO3 content in BNT-KNN-ST system. High recoverable energy storage density of similar to 0.59 J/cm (3) with energy storage efficiency of similar to 64% were obtained in x = 0.16 ceramic samples, which suggested its usefulness for energy-storage capacitor applications.