Ultrahigh energy density in short-range tilted NBT-based lead-free multilayer ceramic capacitors by nanodomain percolation

DOI: 10.1016/j.ensm.2021.01.023

Authors: Hongfen Ji (University of Sheffield; Xi'an Technological University) , Dawei Wang (University of Sheffield) , Weichao Bao (Shanghai Institute of Ceramics) , Zhilun Lu (University of Sheffield; The Henry Royce Institute) , Ge Wang (University of Sheffield) , Huijing Yang (University of Sheffield; Tangshan Normal University) , Ali Mostaed (University of Sheffield; University of Oxford) , Linhao Li (University of Sheffield) , Antonio Feteira (Sheffield Hallam University) , Shikuan Sun (University of Sheffield) , Fangfang Xu (Shanghai Institute of Ceramics) , Dejun Li (Tianjin Normal University) , Chao-Jie Ma (Beijing Institute of Technology) , Shi-Yu Liu (Tianjin Normal University) , Ian M. Reaney (University of Sheffield)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Energy Storage Materials , VOL 12

State: Published (Approved)
Published: January 2021
Diamond Proposal Number(s): 21714

Abstract: Dense pseudocubic 0.62Na0.5Bi0.5TiO3-0.3Sr0.7Bi0.2TiO3-0.08BiMg2/3Nb1/3O3 (NBT-SBT-0.08BMN) ceramics with excellent recoverable energy density, Wrec = 7.5 J/cm3, and conversion efficiency, η = 92%, were synthesized. Large electric breakdown strength was facilitated by electrical homogeneity, high resistivity and large activation energy (1.86 eV). Transmission electron microscopy identified the presence of polar nano-regions (PNRs) in a matrix of short coherence in-phase and antiphase octahedral tilting. Combining polar and tilt order restricted the crystal classes of PNRs to tetragonal, orthorhombic and monoclinic. Using these symmetries, the enhancement of polarization was explained using Landau-Devonshire phenomenology and percolation theory. Octahedral tilting and introduction of larger B-site ions (Mg2+, Nb5+) inhibited long range polar coupling, minimizing strain and maximizing η. Wrec was further improved to 18 J/cm3 (>1000 kV/cm) in multilayers whose properties were stable from 0.01–100 Hz, from 20°C–160°C and up to 106 cycles, attractive for pulsed power applications and power electronics.

Journal Keywords: Na0.5Bi0.5TiO3; capacitors; relaxors; polar nanoregions; octahedral tilting

Subject Areas: Materials, Physics, Energy


Instruments: I15-Extreme Conditions

Added On: 03/02/2021 10:29

Discipline Tags:

Energy Storage Energy Ceramics Physics Electronics Energy Materials Materials Science

Technical Tags:

Diffraction