Dielectric properties and excellent energy storage density under low electric fields for high entropy relaxor ferroelectric (Li0.2Ca0.2Sr0.2Ba0.2La0.2)TiO3 ceramic

Abstract

High entropy relaxor ferroelectrics, are a representative type of dielectric with exceptional properties and play an indispensable role in the next-generation pulsed power capacitor market. In this paper, a high-entropy relaxor ferroelectric ceramic (Li0.2Ca0.2Sr0.2Ba0.2La0.2)TiO3 successfully designed and synthesized using the traditional solid-state reaction method. The microstructure, dielectric properties, and energy storage characteristics of the ceramics were systematically investigated. The ceramic exhibited a dense microstructure with a single-phase perovskite structure and small grain size. The unique microstructure and high insulation not only wides the band gap, but also minimizes residual polarization and resulting in higher energy density (Eb) 1.51 J/cm3 and efficiency (η) of 89.6% at a low field strength of 260 kV/cm. Furthermore, the observed anomalous behavior in dielectric relaxation was explained within the context of high entropy ceramics. The material also exhibited excellent temperature/frequency stability and fast charging-discharging speed (∼35 ns). These results demonstrate the effectiveness of high entropy strategy to develop high-performance energy storage capacitors.