High energy storage performance in (Pb0.858Ba0.1La0.02Y0.008)(Zr0.65Sn0.3Ti0.05)O3- (Pb0.97La0.02)(Zr0.9Sn0.05Ti0.05)O3 anti-ferroelectric composite ceramics

New anti-ferroelectric composite ceramics of (Pb0.858Ba0.1La0.02Y0.008)(Zr0.65Sn0.3Ti0.05)O3- (Pb0.97La0.02)(Zr0.9Sn0.05Ti0.05)O3 (PBLYZST-PLZST) have been fabricated by the conventional solid-state reaction process. The effect of PBLYZST/PLZST ratio on phase structure, dielectric, anti-ferroelectric and energy storage properties has been investigated in detail. The X-ray diffraction, field emission scanning electron microscopy and energy-dispersive spectrometry analysis illustrate that the composites are composed of tetragonal perovskite, orthorhombic perovskite and small amount of pyrochlore phases. With the increase of PLZST content, the two dielectric peaks, which link with AFEO to AFET and AFET to PE phase transition respectively, shift toward higher temperature, suggesting that the anti-ferroelectric temperature stability of the composites is enhanced. The composite ceramics with 50 wt % PLZST content possess a considerable FE-to-AFE phase transition electric field of 130 kV/cm and a high saturation polarization of 49.8 uC/cm2 at room temperature. As a result, the maximum value of energy storage density is obtained to be 4.65 J/cm3.