Silver Niobate Lead-Free Antiferroelectric Ceramics: Enhancing Energy Storage Density by B-Site Doping

Abstract

Lead-free dielectric ceramics with high recoverable energy density are highly desired to sustainably meet the future energy demand. AgNbO-based lead-free antiferroelectric ceramics with double ferroelectric hysteresis loops have been proved to be potential candidates for energy storage applications. Enhanced energy storage performance with recoverable energy density of 3.3 J/cm and high thermal stability with minimal energy density variation (<10%) over a temperature range of 20-120 °C have been achieved in W-modified AgNbO ceramics. It is revealed that the W cations substitute the B-site Nb and reduce the polarizability of B-site cations, leading to the enhanced antiferroelectricity, which is confirmed by the polarization hysteresis and dielectric tunability. It is believed that the polarizability of B-site cations plays a dominant role in stabilizing the antiferroelectricity in AgNbO system, in addition to the tolerance factor, which opens up a new design approach to achieve stable antiferroelectric materials.

Lead‐free Ag1−3xLaxNbO3 antiferroelectric ceramics with high‐energy storage density and efficiency

“…It should be noted that the energy storage efficiency η also increases from 0.42 (AN) to 0.63 (LAN2) and 0.87 (LAN5) due to the remarkably increased E F , E A and reduced E F ‐ E A with the incorporation of La 3+ . The results demonstrate the Ag 1−3 x La x NbO 3 ceramics exhibit more attractive comprehensive energy storage performance (with both high W rec and η ) than most of the reported AgNbO 3 ‐based and other lead‐free antiferroelectric ceramics (Figure B), making it promising a candidate for energy storage applications.…”

“…The energy storage properties of the as‐prepared LAN ceramics in this work and some other lead‐free antiferroelectric ceramics in literatures. A, W rec and η ; B, energy storage properties of AN and other lead‐free antiferroelectric ceramics, 0.828(Bi 0.5 Na 0.5 )TiO 3 –0.72BaTiO 3 –0.10NaNbO 3 (BNTBT–NN), 0.89(Bi 0.5 Na 0.5 )TiO 3 –0.06BaTiO 3 –0.05(K 0.5 Na 0.5 )NbO 3 (BNT–BT–KNN), AgNbO 3 (AN), Ag AgNbO 3 –0.2%MnO 2 (ANMn), Ag 0.97 Bi 0.01 NbO 3 (BAN), AgNbO 3 –0.1wt%WO 3 (AWN), Ag(Nb 0.85 Ta 0.15 )O 3 (ANT) [Color figure can be viewed at wileyonlinelibrary.com]…”

Antiferroelectric‐ferroelectric phase transition in lead‐free AgNbO3 ceramics for energy storage applications

“…It should be noted that the polarization of AgNbO 3 ceramics, especially P r , is susceptible not only to the phase structure, but also extrinsic factors such as domain wall motion, dielectric loss or leakage current. 23,26 This explains why P r demonstrates slight increase with increasing temperature, with no evident change of the M 1 -M 2 transition temperature, as shown in Figure 3B,D and F. Based on the above discussions, it can be concluded that the elevated temperature has the similar effect on dielectric behavior and phase transition as high electric field in AgNbO 3 ceramics, which is expected to decrease the transition energy barrier and shift the FIE-FE phase transition to lower critical electric fields. However, there is a certain critical electric field below which the FIE-FE phase transition would not occur even at elevated temperature.…”

“…In 2016, breakthrough was reported in AgNbO 3 ‐based ceramics where recoverable energy densities of 2.1 and 2.5 J/cm 3 were achieved in pure and MnO 2 ‐doped AgNbO 3 ceramics . By further modification with Bi 2 O 3 , Ta 2 O 5 and WO 3 dopants, the energy density as well as thermal stability of AgNbO 3 ‐based ceramics have been greatly enhanced, demonstrating that the AgNbO 3 ‐based ceramics are promising for energy storage applications.…”

Recent progress of ecofriendly perovskite-type dielectric ceramics for energy storage applications

“…80 Later, introduction of W 6þ and Ta 5þ cations at the B-site in AgNbO 3 ceramics have been considered as efficient avenue for enhancing energy storage performance. 81,82 The authors suggested that the introduction of aliovalent cations enhance antiferroelectricity, reduce B-site polarizations and optimize microstructure in AgNbO 3 ceramics. Enhanced BDS and AFE properties by substitution of W 6þ and Ta 5þ result in excellent energy storage performance.…”