Lead‐free Ag_1−3xLa_xNbO₃ antiferroelectric ceramics with high‐energy storage density and efficiency

Abstract

Environmentally benign lead-free bulk ceramics with high recoverable energy density (W rec ) are very attractive in advanced pulsed power capacitors. In this work, composition engineering was adopted by La 3+ modification to improve the energy storage performance of Ag 1−3x La x NbO 3 ceramics. It was found that the antiferroelectric (AFE) phase was stabilized after La 3+ substitution, as a result of the reduced tolerance factor t. Significant improvement of W rec and energy storage efficiency (η) were achieved with value of 3.12 J/cm 3 and 0.63 for x = 0.02 at an electric field of 230 kV/cm, more than 1.5 times the value of pure AgNbO 3 (W rec = 1.9 J/cm 3 , η = 0.40). The excellent energy storage properties are resulted from the increased antiferroelectric-ferroelectric phase transition electric field (E F ), ferroelectric-antiferroelectric phase transition electric field (E A ), and breakdown electric field (E b ). The enhanced E b was ascribed to the decreased grain size and increased electrical resistivity upon La 3+ modification. The feature makes Ag 1−3x-La x NbO 3 a potential candidate for energy storage applications. K E Y W O R D Sdielectric materials/properties, energy storage, ferroelectricity/ferroelectric materials, lead-free ceramics

Electroceramics for High-Energy Density Capacitors: Current Status and Future Perspectives

“…Most conventional AFEs exhibit low W rec (∼1.5–2 J cm –3 ) and η (∼40%), which can be optimized to W rec > 3 J cm –3 and η > 50% (enhanced-AFEs) by strategies described in the work of Lu and others. 348 , 350 − 352 , 357 , 359 , 363 , 366 Similar values of ΔP (30–40 μC cm –2 ) are found for AFEs and enhanced-AFEs which reflects an intrinsic limitation of AFE materials, i.e. when antiparallel polar coupling is fully switched to polar under electric field, P max reaches saturation and is difficult to enhance unlike for RFEs ( section 4.1 ).…”

“… (a) Temperature- 42 , 43 , 130 , 131 , 208 , 242 , 297 , 337 , 348 , 352 , 357 , 359 and (b) frequency-dependent W rec for some reported electroceramic materials for high energy density capacitors. 276 , 295 , 297 , 337 , 416 …”

Greatly enhanced energy storage and discharge properties of AgNbO3 ceramics with a stable antiferroelectric phase and high breakdown strength using hydrothermally synthesized powders

“…shows E b and energy storage performances of recently reported pure AgNbO 3 ceramics. 3,4,10,11,13,26–36 Clearly, hydrothermally fabricated AgNbO 3 ceramics exhibit obvious advantages in terms of E b , W rec and η . Therefore, it is proved that the strategy proposed in this work to improve the energy storage capacity of AgNbO 3 ceramics is effective.…”

High energy storage density and efficiency with excellent temperature and frequency stabilities under low operating field achieved in Ag0.91Sm0.03NbO3-modified Na0.5Bi0.5TiO3-BaTiO3 ceramics

“…Additionally, Zhao et al also found that lead-free AgNbO 3 ceramics showed a characteristic antiferroelectric double hysteresis loop at a low electric field of 13 kV/mm and a high W rec of 1.6 J/cm 3 at 14 kV/mm was achieved [16]. This finding has triggered a burst of research activities on AgNbO 3 ceramics [54][55][56][57][58][59][60][61][62][63][64]. Among them, Luo et al reported that Ag 0.91 Sm 0.03 NbO 3 (ASN) sample showed excellent energy storage performance (W rec = 5.2 J/cm 3 and η = 68.5%) [64].…”