Weak nonlinearity engineering induced excellent low-field energy storage performance in BNTST-based lead-free relaxors

• Published in: Journal of alloys and compounds Vol. 1008; p. 176753
• Main Authors: Li, Xinheng, Zhu, Chaoqiong, Li, Aoyu, Liang, Lanqing, Li, Shiheng, Xu, Cheng, Cai, Ziming, Feng, Peizhong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.12.2024
• Subjects: BNT-Based ceramics; Energy storage; High effective dielectric constant; High polarization; Linear-like relaxors; High effective dielectric constant; High polarization; Linear-like relaxors; BNT-Based ceramics; Energy storage
• ISSN: 0925-8388
• DOI: 10.1016/j.jallcom.2024.176753

With continuously developing of electronic power systems, ceramic dielectrics with superior energy-storage performance have received widespread attention. Relaxor ferroelectric ceramics have become a research hotspot due to the small hysteresis, while how to modify the strong nonlinear and limited polarization difference is still a huge challenge for achieving a desirable discharge energy density (Wdis). In this work, a linear-like relaxors system with high polarization is constructed by introducing antiferroelectric phase (NaNbO3, NN) into relaxor ferroelectric phase (0.6Bi0.5Na0.5TiO3-0.4SrTiO3, BNTST). Benefitting from the improvement on DC-bias stability and the high zero-field dielectric constant, the 0.90BNTST-0.10NN ceramic successfully keeps a high effective dielectric constant even at high electric fields (εr@120kV/cm=1670), which ensures the high polarization and optimized linearity of P-E loops. As a result, 0.90BNTST-0.10NN ceramics achieve superior energy storage performance with a high Wdis (5.79 J/cm3) and high efficiency (91.5 %). These findings provide an effective nonlinearity-weakening approach to explore promising candidate in practical energy-storage applications. •A weak-nonlinearity engineering strategy is proposed to improve the energy storage performance of BNT-ST-based ceramic system.•A large Wdis of 5.79 J/cm3 is obtained at 400 kV/cm in 0.9BNTST-0.1NN ceramic, with a η of 91.5 %.•0.90BNTST-0.10NN ceramic keeps a high effective dielectric constant even at high electric fields (εr@120kV/cm=1670).