Achieving high energy storage performance and breakdown strength in modified strontium titanate ceramics

Lead-free ceramic capacitors with attractive properties such as their environmental friendliness, superior energy density, fast charge and discharge rate, and superior stability have recently received increased attention to meet liber market demands for energy storage devices in low consumption systems. However, overcoming its relatively low energy storage capacity is becoming extremely important. Based on this task, La3+ and Li+ co-doped SrTiO3 ceramics are fabricated by a solid-state reaction method. The effect of La3+ and Li+ contents on the structural, microstructure, dielectrics, and energy storage properties of SrTiO3 ceramics are systematically studied. XRD confirmed the phase structure along with Rietveld refinement studies. The morphological structure is studied using SEM. Through X-ray photoelectron spectroscopy spectra, the chemical composition and the chemical state of Sr(1-x)(Li0.50La0.50)(x)TiO3 (SLLTx); (0 <= x <= 8%) ceramics are studied. The energy storage properties are theoretically estimated by integrating the polarization versus electric field P-E hysteresis loop. The results show an increase in La3+ and Li+ content (x), resulting in enhanced dielectric breakdown strength, and maximum polarization yields a higher energy storage density. In the sample with x = 8%, it is found that the energy density is 2.455 J/cm(3) and the energy efficiency is more than 90%. The further improvement in dielectric constant, dielectric breakdown strength, enhanced energy storage densities and the energy efficiency maintained > 90% make these materials commercially promising for energy storage device capacitors for a wide range of energy storage applications.