Hydrothermal synthesized AgNbO3 powders: Leading to greatly improved electric breakdown strength in ceramics

Ceramic-Based Dielectric Materials for Energy Storage Capacitor Applications

Materials offering high energy density are currently desired to meet the increasing demand for energy storage applications, such as pulsed power devices, electric vehicles, high-frequency inverters, and so on. Particularly, ceramic-based dielectric materials have received significant attention for energy storage capacitor applications due to their outstanding properties of high power density, fast charge-discharge capabilities, and excellent temperature stability relative to batteries, electrochemical capacitors, and dielectric polymers. In this paper, we present fundamental concepts for energy storage in dielectrics, key parameters, and influence factors to enhance the energy storage performance, and we also summarize the recent progress of dielectrics, such as bulk ceramics (linear dielectrics, ferroelectrics, relaxor ferroelectrics, and anti-ferroelectrics), ceramic films, and multilayer ceramic capacitors. In addition, various strategies, such as chemical modification, grain refinement/microstructure, defect engineering, phase, local structure, domain evolution, layer thickness, stability, and electrical homogeneity, are focused on the structure-property relationship on the multiscale, which has been thoroughly addressed. Moreover, this review addresses the challenges and opportunities for future dielectric materials in energy storage capacitor applications. Overall, this review provides readers with a deeper understanding of the chemical composition, physical properties, and energy storage performance in this field of energy storage ceramic materials.

High Energy Storage Performance in La-Doped AgNbO3 Ceramics via Tape Casting

AgNbO₃-based Pb-free antiferroelectric (AFE) ceramics have attracted increasing interest owing to their excellent potential in energy storage applications. Herein, a high recoverable energy storage density (W_rec) of 7.62 J/cm³ is realized in La-doped AgNbO₃ ceramics prepared via tape casting. The high W_rec is attributed to high breakdown strength E_b of 380 kV/cm induced by dense microstructure as well as fine grain size and enhanced AFE stability stemming from M₂ phase and reduced tolerance factor t. The high W_rec exceeding 6 J/cm³ was maintained in a wide temperature range of 20-150 °C and exhibited frequency stability with less than 8% variation in a range of 1-200 Hz. The discharge energy density W_d exhibited temperature stability at 30-110 °C with less than 9% variation. Our research provides a good method for producing AgNbO₃-based ceramics having high energy storage performances.

Synergic Enhancement of Energy Storage Density and Efficiency in MnO2-Doped AgNbO3@SiO2 Ceramics via A/B-Site Substitutions

Dielectric energy storage devices with high power density show great potential in applications of smart grids, electrical vehicles, pulsed power weapons, and so on. However, their limited recoverable energy density badly restricts their utilization and harms the miniaturization, portability, and integration of electronics. Herein, equivalent amounts of Bi₂O₃ and Sc₂O₃ were introduced to improve the energy storage property of 0.10 wt % MnO₂-doped AgNbO₃@SiO₂ ceramics by simultaneously enhancing the maximum polarization, breakdown strength, and relaxation feature. It is particularly interesting that the AgNbO₃-based ceramics with 4 mol % Bi₂O₃ and Sc₂O₃ demonstrate the recoverable energy storage density of 5.9 J/cm³ with the energy storage efficiency of 71%, exhibiting 1.9 and 1.4 times enhancement compared to 0.10 wt % MnO₂-doped AgNbO₃@SiO₂ ceramics. In addition, the benign energy storage performance can be maintained at elevated temperatures and frequencies and up to 10⁵ cycling, indicating great potential in advanced high-power applications.