Ultrahigh energy storage in high-entropy ceramic capacitors with polymorphic relaxor phase

Abstract

Ultrahigh–power-density multilayer ceramic capacitors (MLCCs) are critical components in electrical and electronic systems. However, the realization of a high energy density combined with a high efficiency is a major challenge for practical applications. We propose a high-entropy design in barium titanate (BaTiO 3 )–based lead-free MLCCs with polymorphic relaxor phase. This strategy effectively minimizes hysteresis loss by lowering the domain-switching barriers and enhances the breakdown strength by the high atomic disorder with lattice distortion and grain refining. Benefiting from the synergistic effects, we achieved a high energy density of 20.8 joules per cubic centimeter with an ultrahigh efficiency of 97.5% in the MLCCs. This approach should be universally applicable to designing high-performance dielectrics for energy storage and other related functionalities.

Excellent Energy Storage Performance of Perovskite High-Entropy Oxide-Modified (Bi0.5Na0.5)TiO3-Based Ceramics

“…Zhang et al explored the domain structures of BaTiO 3 -based high-entropy ceramics using TEM and found that the domain size decreased to 0.8–3.6 nm with increasing entropy. The nanodomains were accompanied by improved relaxation features, which were closely relevant to local composition disorder in high-entropy systems . According to these reports, it can be believed that in the present work, the local random field induced by increasing entropy can destroy the long-range ordered ferroelectric domains, which makes the large-scale domains evolve into small-scale domains, resulting in strong relaxation behavior.…”

“…The nanodomains were accompanied by improved relaxation features, which were closely relevant to local composition disorder in high-entropy systems. 36 According to these reports, it can be believed that in the present work, the local random field induced by increasing entropy can destroy the long-range ordered ferroelectric domains, which makes the large-scale domains evolve into small-scale domains, resulting in strong relaxation behavior. Furthermore, Figure 4h shows that the tan δ values of the asprepared samples are small and decrease with the increasing BNCBSTN content, indicating that BNCBSTN addition can reduce the dielectric loss.…”

Improved energy storage properties achieved in NaNbO3-based relaxor antiferroelectric ceramics via anti-parallel polar nanoregion design

“…Recently, researchers have made considerable investments in lead-free relaxor ferroelectric/antiferroelectric ceramics, which include NaNbO 3 (NN), 3,4 K 0.5 Na 0.5 NbO 3 (KNN), 5,6 BaTiO 3 (BT), 7,8 Bi 0.5 Na 0.5 TiO 3 (BNT), 9–11 and BiFeO 3 (BF) 12,13 ceramics. With a 3.4 eV broad band gap and significant polarization responses, NN-based ceramics are regarded as one of the potential choices among them.…”