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

By Zhilun Lu, Wei-Chao Bao, Ge Wang, Shikuan Sun, Linhao Li, Jinglei Li, Huijing Yang, Hongfen Ji, A. Feteira, Dejun Li and 5 more. Nano Energy, 2021

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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.

Subfields: Biomedical Engineering, Electronic, Optical and Magnetic Materials, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/b998e838dbf7ee704697a788d1524b396e0a1c21