Remarkable improvement of energy storage performance of Gd2O3-doped BNT-based relaxor ferroelectric ceramics

• Published in: Journal of materials science. Materials in electronics 2024-03, Vol.35 (9), p.633, Article 633
• Main Authors: Wen, Hongjuan, Wu, Xiusheng, Jin, Zhengquan, Shi, Sijia, Cao, Jufang, Zhou, Naiji, Huang, Yujia
• Format: Article
• Language: English
• Subjects: Bismuth titanate; Breakdown; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Density; Discharge; Electrical properties; Energy storage; Ferroelectric materials; Ferroelectricity; Gadolinium; Gadolinium oxides; Lead free; Materials Science; Optical and Electronic Materials; Relaxors; Room temperature
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-024-12403-z

Bi 0.5 Na 0.5 TiO 3 (BNT) is a lead-free ferroelectric ceramic that has received much attention in recent years. However, the pure BNT presents a tetragonal structure with considerable remanent polarization at room temperature, which lead to its low energy storage efficiency thus limiting its application in energy storage. In this paper, on the basis of the introduction of Ba 0.3 Sr 0.7 TiO 3 (BST), NaNbO 3 (NN) into BNT to form a relaxor ferroelectric, Gd 2 O 3 is further doped to refine grain and reduce oxygen vacancy concentration thereby improving the breakdown strength, which is beneficial to improve its energy storage performance. A series of ceramic samples of 0.9 (0.5BNT-0.5BST)-0.1NN +  x wt%Gd ( x  = 0, 0.5, 1, 2.5, 3) were prepared by the solid-state reaction method. The effect of Gd 2 O 3 on the microstructure and electrical properties of the systems was investigated. The results show that a suitable doping level of Gd 2 O 3 can significantly refine the grains and improve the breakdown strength of the system. For x  = 2.5 ceramic sample obtained a high energy storage density of W rec = 4.86 J/cm 3 and an energy storage efficiency of η  = 86% at 250 kV/cm. Furthermore, this sample exhibited a stable discharge density ( W d ≥ 1.44 J/cm 3 ) and an ultra-fast discharge rate ( t 0.9 ≤ 0.056 µs) in the temperature range of 140 kV/cm, 40∼140 °C.