Synthesis and characterizations of NaNbO3 modified BNT–BT–BKT ceramics for energy storage applications

Lead-free (1−x)[0.884BNT–0.036BT–0.08BKT]–xNaNbO3 samples (with x=0, 0.04, 0.08, 0.12 and 0.16) were synthesized in single perovskite phase by solid state reaction route. Decrease of grain size with the increase of NaNbO3/NN content was related to the grain boundary pinning effect. Dielectric study confirmed the relaxor nature of x=0.08, 0.12 and 0.16 samples. Energy storage density and efficiency were calculated from polarization vs. electric field hysteresis loops. Value of energy storage efficiency increased with the increase of NaNbO3 content. A relatively large energy storage density of ~0.721 J/cm3 was obtained in the x=0.08 samples. Electric field induced polarization and strain loops, respectively suggested the increase of AFE ordering with the increase of NN content.