Microstructures, piezoelectric properties and energy harvesting performance of undoped (K0.5Na0.5)NbO3 lead-free ceramics fabricated via two-step sintering

G. Ye; J. Wade-Zhu; J. Zou; T. Zhang; T. W. Button; J. Binner

doi:10.1016/j.jeurceramsoc.2020.02.035

Microstructures, piezoelectric properties and energy harvesting performance of undoped (K_0.5Na_0.5)NbO₃ lead-free ceramics fabricated via two-step sintering

G. Ye^*, J. Wade-Zhu, J. Zou, T. Zhang, T. W. Button, J. Binner

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

4 Citations (Scopus)

Abstract

Piezoelectric energy harvesters have become increasingly popular in the field of green energy because of the ability to convert low-frequency environmental vibrations into usable electricity. To fabricate high-performance energy harvesters, the key requirements are piezoelectric ceramics with a small grain size, of near-full density, the intended stoichiometric ratio and a high transduction coefficient. In this work, the effects of two-step sintering on the sinterability, microstructure, piezoelectric properties and energy harvesting performance of (K_0.5Na_0.5)NbO₃ were systematically investigated. Compared with conventional single-step sintering, two-step sintering samples were of higher density, increasing from 91 % to 95 % of theoretical, reduced mean grain size, down from 17 μm to 7.5 μm, and decreased evaporation of the alkali metals. This translated into an improved piezoelectric performance (d₃₃ ∼122 pC/N, k_p ∼36 % and Q_m ∼76), a higher transduction coefficient and energy conversion efficiency as well as a higher open-circuit voltage and power density. This demonstrates the potential of two-step sintering as a high through-put sintering technique for moderate-performance, pure KNN ceramics.

Original language	English
Pages (from-to)	2977-2988
Number of pages	12
Journal	Journal of the European Ceramic Society
Volume	40
Issue number	8
DOIs	https://doi.org/10.1016/j.jeurceramsoc.2020.02.035
Publication status	Published - Jul 2020

Bibliographical note

Funding Information:
The work was supported by grants from the UK's Engineering and Physical Science Research Council ‘Multi scale tuning of interfaces and surfaces for energy applications’, grant number EP/P007821/1 and School of Metallurgy and Materials, University of Birmingham . The authors also appreciate the contributions from Dr. Daniel Reed, Dr. Vinothini Venkatachalam, Mr. Carl Meggs and Mr. Paul Stanley from the University of Birmingham, also Prof. Mike Reece from the Queen Mary University of London for assistance.

Funding Information:
The work was supported by grants from the UK's Engineering and Physical Science Research Council ?Multi scale tuning of interfaces and surfaces for energy applications?, grant number EP/P007821/1 and School of Metallurgy and Materials, University of Birmingham. The authors also appreciate the contributions from Dr. Daniel Reed, Dr. Vinothini Venkatachalam, Mr. Carl Meggs and Mr. Paul Stanley from the University of Birmingham, also Prof. Mike Reece from the Queen Mary University of London for assistance.

Publisher Copyright:
© 2020 Elsevier Ltd

Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.

Keywords

Density
Grain size
Potassium sodium niobate (KNaNbO)
Sintering kinetics
Two-step sintering

ASJC Scopus subject areas

Ceramics and Composites
Materials Chemistry

Access to Document

10.1016/j.jeurceramsoc.2020.02.035

Cite this

@article{d4b13d0efa5d4cca8b54a748a8c70556,

title = "Microstructures, piezoelectric properties and energy harvesting performance of undoped (K0.5Na0.5)NbO3 lead-free ceramics fabricated via two-step sintering",

abstract = "Piezoelectric energy harvesters have become increasingly popular in the field of green energy because of the ability to convert low-frequency environmental vibrations into usable electricity. To fabricate high-performance energy harvesters, the key requirements are piezoelectric ceramics with a small grain size, of near-full density, the intended stoichiometric ratio and a high transduction coefficient. In this work, the effects of two-step sintering on the sinterability, microstructure, piezoelectric properties and energy harvesting performance of (K0.5Na0.5)NbO3 were systematically investigated. Compared with conventional single-step sintering, two-step sintering samples were of higher density, increasing from 91 % to 95 % of theoretical, reduced mean grain size, down from 17 μm to 7.5 μm, and decreased evaporation of the alkali metals. This translated into an improved piezoelectric performance (d33 ∼122 pC/N, kp ∼36 % and Qm ∼76), a higher transduction coefficient and energy conversion efficiency as well as a higher open-circuit voltage and power density. This demonstrates the potential of two-step sintering as a high through-put sintering technique for moderate-performance, pure KNN ceramics.",

keywords = "Density, Grain size, Potassium sodium niobate (KNaNbO), Sintering kinetics, Two-step sintering",

author = "G. Ye and J. Wade-Zhu and J. Zou and T. Zhang and Button, {T. W.} and J. Binner",

note = "Funding Information: The work was supported by grants from the UK's Engineering and Physical Science Research Council {\textquoteleft}Multi scale tuning of interfaces and surfaces for energy applications{\textquoteright}, grant number EP/P007821/1 and School of Metallurgy and Materials, University of Birmingham . The authors also appreciate the contributions from Dr. Daniel Reed, Dr. Vinothini Venkatachalam, Mr. Carl Meggs and Mr. Paul Stanley from the University of Birmingham, also Prof. Mike Reece from the Queen Mary University of London for assistance. Funding Information: The work was supported by grants from the UK's Engineering and Physical Science Research Council ?Multi scale tuning of interfaces and surfaces for energy applications?, grant number EP/P007821/1 and School of Metallurgy and Materials, University of Birmingham. The authors also appreciate the contributions from Dr. Daniel Reed, Dr. Vinothini Venkatachalam, Mr. Carl Meggs and Mr. Paul Stanley from the University of Birmingham, also Prof. Mike Reece from the Queen Mary University of London for assistance. Publisher Copyright: {\textcopyright} 2020 Elsevier Ltd Copyright: Copyright 2020 Elsevier B.V., All rights reserved.",

year = "2020",

month = jul,

doi = "10.1016/j.jeurceramsoc.2020.02.035",

language = "English",

volume = "40",

pages = "2977--2988",

journal = "Journal of the European Ceramic Society",

issn = "0955-2219",

publisher = "Elsevier",

number = "8",

}

TY - JOUR

T1 - Microstructures, piezoelectric properties and energy harvesting performance of undoped (K0.5Na0.5)NbO3 lead-free ceramics fabricated via two-step sintering

AU - Ye, G.

AU - Wade-Zhu, J.

AU - Zou, J.

AU - Zhang, T.

AU - Button, T. W.

AU - Binner, J.

N1 - Funding Information: The work was supported by grants from the UK's Engineering and Physical Science Research Council ‘Multi scale tuning of interfaces and surfaces for energy applications’, grant number EP/P007821/1 and School of Metallurgy and Materials, University of Birmingham . The authors also appreciate the contributions from Dr. Daniel Reed, Dr. Vinothini Venkatachalam, Mr. Carl Meggs and Mr. Paul Stanley from the University of Birmingham, also Prof. Mike Reece from the Queen Mary University of London for assistance. Funding Information: The work was supported by grants from the UK's Engineering and Physical Science Research Council ?Multi scale tuning of interfaces and surfaces for energy applications?, grant number EP/P007821/1 and School of Metallurgy and Materials, University of Birmingham. The authors also appreciate the contributions from Dr. Daniel Reed, Dr. Vinothini Venkatachalam, Mr. Carl Meggs and Mr. Paul Stanley from the University of Birmingham, also Prof. Mike Reece from the Queen Mary University of London for assistance. Publisher Copyright: © 2020 Elsevier Ltd Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/7

Y1 - 2020/7

N2 - Piezoelectric energy harvesters have become increasingly popular in the field of green energy because of the ability to convert low-frequency environmental vibrations into usable electricity. To fabricate high-performance energy harvesters, the key requirements are piezoelectric ceramics with a small grain size, of near-full density, the intended stoichiometric ratio and a high transduction coefficient. In this work, the effects of two-step sintering on the sinterability, microstructure, piezoelectric properties and energy harvesting performance of (K0.5Na0.5)NbO3 were systematically investigated. Compared with conventional single-step sintering, two-step sintering samples were of higher density, increasing from 91 % to 95 % of theoretical, reduced mean grain size, down from 17 μm to 7.5 μm, and decreased evaporation of the alkali metals. This translated into an improved piezoelectric performance (d33 ∼122 pC/N, kp ∼36 % and Qm ∼76), a higher transduction coefficient and energy conversion efficiency as well as a higher open-circuit voltage and power density. This demonstrates the potential of two-step sintering as a high through-put sintering technique for moderate-performance, pure KNN ceramics.

AB - Piezoelectric energy harvesters have become increasingly popular in the field of green energy because of the ability to convert low-frequency environmental vibrations into usable electricity. To fabricate high-performance energy harvesters, the key requirements are piezoelectric ceramics with a small grain size, of near-full density, the intended stoichiometric ratio and a high transduction coefficient. In this work, the effects of two-step sintering on the sinterability, microstructure, piezoelectric properties and energy harvesting performance of (K0.5Na0.5)NbO3 were systematically investigated. Compared with conventional single-step sintering, two-step sintering samples were of higher density, increasing from 91 % to 95 % of theoretical, reduced mean grain size, down from 17 μm to 7.5 μm, and decreased evaporation of the alkali metals. This translated into an improved piezoelectric performance (d33 ∼122 pC/N, kp ∼36 % and Qm ∼76), a higher transduction coefficient and energy conversion efficiency as well as a higher open-circuit voltage and power density. This demonstrates the potential of two-step sintering as a high through-put sintering technique for moderate-performance, pure KNN ceramics.

KW - Density

KW - Grain size

KW - Potassium sodium niobate (KNaNbO)

KW - Sintering kinetics

KW - Two-step sintering

UR - http://www.scopus.com/inward/record.url?scp=85079905985&partnerID=8YFLogxK

U2 - 10.1016/j.jeurceramsoc.2020.02.035

DO - 10.1016/j.jeurceramsoc.2020.02.035

M3 - Article

AN - SCOPUS:85079905985

SN - 0955-2219

VL - 40

SP - 2977

EP - 2988

JO - Journal of the European Ceramic Society

JF - Journal of the European Ceramic Society

IS - 8

ER -