Improved Energy Storage Properties Achieved in (K, Na)NbO₃‑Based Relaxor Ferroelectric Ceramics via a Combinatorial Optimization Strategy

Abstract

Although ceramic dielectric materials have been extensively explored owing to their numerous advantages, there are still obstacles in the collaborative enhancement of recoverable energy density (W rec ) and efficiency (η). In this work, a combinatorial optimization strategy is proposed to optimize energy storage properties of (K, Na)NbO 3 -based ceramics, that is, drive a specific temperature region between the temperature of maximum dielectric constant and the Burns temperature to room temperature under the guidance of phase field simulation to induce the polar nanoregions, then further improve the breakdown strength by repeated rolling process. As a result, an ultrahigh W rec of 6.7 J cm −3 and a high η of 92% at 600 kV cm −1 are achieved simultaneously in the 0.85K 0.5 Na 0.5 NbO 3 -0.15Bi(Zn 2/3 Ta 1/3 )O 3 ceramic prepared by repeated rolling process, together with excellent temperature stability under 400 kV cm −1 over a temperature range of 25 to 150 °C, outperforming all reported (K, Na)NbO 3based energy storage ceramics. This approach should also be generalizable for designing high-performance dielectrics for electrical energy storage applications.

High‐Performance Strain of Lead‐Free Relaxor‐Ferroelectric Piezoceramics by the Morphotropic Phase Boundary Modification

“…Recently, significant progress has been made in using phase-field simulations for the exploration and prediction of domain structures, ferroelectric polarization, piezoelectricity, and phase transformations in various piezoelectric materials. [33][34][35] However, phase-field models for the characterization of electric-field-induced strains in BNT-based ceramics remain nascent. [36] Therefore, enabled by phase-field guidance and rational composition design, development of highperformance BNT-based ceramics is desirable for applications that feature actuators operating in a wide range of temperatures.…”

Energy storage performance of BiFeO3–SrTiO3–BaTiO3 relaxor ferroelectric ceramics

“…Figure 6 exhibits the comparison of W rec and η values between x = 0.12 in this work and some recently reported typical lead‐free dielectric ceramics, including Bi 0.5 Na 0.5 TiO 3 (BNT)‐, BaTiO 3 (BT)‐, BiFeO 3 (BF)‐, and K 0.5 Na 0.5 NbO 3 (KNN)‐based ceramics 12,13,18,23–37 . As can be seen, excellent energy storage properties have been achieved in many works, but the simultaneous enhancement of W rec (> 5 J/cm 3 ) and η (> 80%) is still a challenge.…”

“…Figure 6 exhibits the comparison of W rec and η values between x = 0.12 in this work and some recently reported typical lead-free dielectric ceramics, including Bi 0.5 Na 0.5 TiO 3 (BNT)-, BaTiO 3 (BT)-, BiFeO 3 (BF)-, and K 0.5 Na 0.5 NbO 3 (KNN)-based ceramics. 12,13,18,[23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] As can be seen, excellent energy storage properties have been achieved in many works, but the simultaneous enhancement of W rec (> 5 J/cm 3 ) and η (> 80%) is still a challenge. Fortunately, the x = 0.12 ceramic explored in this work exhibits more superior comprehensive energy storage properties than most of lead-free bulk ceramics.…”

Simultaneously achieving large energy density and high efficiency in NaNbO3–(Sr,Bi)TiO3–Bi(Mg,Zr)O3 relaxor ferroelectric ceramics for dielectric capacitor applications

“…3(d). 4,12,14,[19][20][21]23,[30][31][32][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53] Obviously, NN-SBT-BMZ012 demonstrates both high energy storage density and high efficiency among them. Fig.…”