Mechanism of enhanced energy storage density in AgNbO3-based lead-free antiferroelectrics

Lu, Zhilun; Bao, Weichao; Wang, Ge; Sun, Shi-Kuan; Li, Linhao; Li, Jinglei; Yang, Huijing; Ji, Hongfen; Feteira, Antonio; Li, Dejun; Xu, Fangfang; Kleppe, Annette K.; Wang, Dawei; Liu, Shi-Yu; Reaney, Ian M.

Abstract

The mechanisms underpinning high energy storage density in lead-free Ag1–3xNdxTayNb1-yO3 antiferroelectric (AFE) ceramics have been investigated. Rietveld refinements of in-situ synchrotron X-ray data reveal that the structure remains quadrupled and orthorhombic under electric field (E) but adopts a non-centrosymmetric space group, Pmc21, in which the cations exhibit a ferrielectric configuration. Nd and Ta doping both stabilize the AFE structure, thereby increasing the AFE-ferrielectric switching field from 150 to 350 kV cm−1. Domain size and correlation length of AFE/ferrielectric coupling reduce with Nd doping, leading to slimmer hysteresis loops. The maximum polarization (Pmax) is optimized through A-site aliovalent doping which also decreases electrical conductivity, permitting the application of a larger E. These effects combine to enhance energy storage density to give Wrec = 6.5 J cm−3 for Ag0.97Nd0.01Ta0.20Nb0.80O3.

• Journal Article Type: Article
• Acceptance Date: Sep 19, 2020
• Online Publication Date: Sep 30, 2020
• Publication Date: 2021-01
• Deposit Date: Oct 21, 2021
• Publicly Available Date: Oct 22, 2021
• Journal: Nano Energy
• Print ISSN: 2211-2855
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 79
• Article Number: 105423
• DOI: https://doi.org/10.1016/j.nanoen.2020.105423
• Keywords: Energy storage capacitors, Antiferroelectrics, In-situ synchrotron X-ray diffraction, Silver niobate
• Public URL: http://researchrepository.napier.ac.uk/Output/2814969