Grain size engineered Ba_0.9Sr_0.1Ti_0.9Hf_0.1O₃‐Na_0.5Bi_0.5TiO₃ relaxor ceramics with improved energy storage performance

Abstract

Novel lead‐free diphasic (1‐x)Ba0.9Sr0.1Ti0.9Hf0.1O3‐xNa0.5Bi0.5TiO3 (BSTH‐NBT) ceramic nanocomposites were synthesized via an economically viable modified mechano‐chemical activation technique. In the present investigation, we have developed an energy storage composite material by systematically optimizing the charge transport behavior and charge storage characteristics between the ferroelectric BSTH and piezoelectric NBT phase. The composite with x = 0.09 NBT concentration has shown the best energy storage properties with 1.61 J/cm3 discharge energy density along with 80.1% energy efficiency. The BSTH and NBT had a synergetic effect on the ferroelectric properties of the composites. The improvement in ferroelectric and piezoelectric properties along with excellent aging characteristics in composite materials is mainly attributed to enhancement in microstructural density, grain boundary interface, and stress effects. The improved dispersibility and excellent compatibility between BSTH and NBT phase have resulted in approximately 20% enhancement in breakdown strength of composite compared to pure BSTH ceramic.

Local Heterogeneous Polarization Enhanced Superior Low-Field Energy Storage Performance in Lead-Free Relaxor Ferroelectric Ceramics

“…The polarization and electric field relation ( P – E loop) is highly related to the domain configurations. Much effort has been made to the domain engineering, i.e., by elements doping , or grain refinement, , the long-range ordered microdomains are broken into polar nano regions (PNRs), as shown in Figure b. PNRs are highly active to the applied electric field, leading to a small hysteresis of relaxor ferroelectrics, which is considered an effective approach to enhance energy density and energy efficiency.…”

Superior energy storage performance coupled with excellent electrical characteristics in lead-free Ba0.8Ca0.2TiO3-(Bi0.80Mg0.20) (Ti0.65Mg0.30)O3 ceramics

“…In the past, various isovalent and aliovalent substituents have been incorporated into the BT lattice to enhance the dielectric, ferroelectric, and breakdown strength characteristics [14,15]. The effect of isovalent substituents, such as Ca and Sr at A-site (Ba-site) and Hf and Zr at B-site (Ti-site) of BT have been widely investigated with the purpose of enhancing electrical properties [16,17]. The substitution of Ca at the Ba-site has resulted in a substantial enhancement in dielectric and ferroelectric characteristics.…”