Phase structure, microstructure, electrical and energy storage properties of SBNLT lead free ceramics with Zr⁴⁺ substituted into B-sites

Lead-free (Sr_0.3Bi_0.35Na_0.335Li_0.015) (Ti_1−xZr_x) O₃ ceramics (SBNLT_1−xZr_x) with x = 0–0.04 were prepared via the solid-state combustion technique using glycine as the fuel. The influence of Zr content on the phase structure, microstructure, electrical properties, and energy storage properties of the SBNLT_1−xZr_x ceramics was examined. The presence of a pure perovskite phase was shown by X-ray diffraction (XRD) patterns, with the coexistence of rhombohedral and tetragonal phases in all samples, as certified by the Rietveld refinement method. Scanning electron microscopy (SEM) was utilized to observe the morphology of the SBNLT_1−xZr_x ceramics, which revealed cube shaped grains with anisotropic growth. Average grain size increased from 2.01 to 2.49 µm when x increased from 0 to 0.01 and then reduced with further increases in Zr content. The maximum dielectric constant dropped from 4667 to 2990 when x increased from 0 to 0.04, caused by a shift from the morphotropic phase boundary (MPB). The maximum polarization (P_max) of 29.18 µC/cm², energy storage density (W_total) of 0.851 J/cm³ and recoverable energy storage (W_rec) of 0.609 J/cm³ were achieved when x = 0.02.