Enhancing energy harvesting potential of (K,Na,Li)NbO3-epoxy composites via Li substitution

Title

Enhancing energy harvesting potential of (K,Na,Li)NbO3-epoxy composites via Li substitution

 Author

Deutz, D.B. (TU Delft Novel Aerospace Materials)
Mascarenhas, N.T. (TU Delft Novel Aerospace Materials)
van der Zwaag, S. (TU Delft Novel Aerospace Materials) ORCID 0000-0001-5085-0255
Groen, W.A. (TU Delft Novel Aerospace Materials; TNO) ORCID 0000-0003-4215-2064

 Date

2016

 Abstract

In this study, the influence of Li substitution on the piezoelectric performance of lead-free K0.5Na0.5NbO3 (KNN)-epoxy composites is explored. KNN piezoceramic particles modified with 0-12 mol% of Li are prepared via a double calcination technique, resulting in a perovskite particulate which transitions from an orthorhombic to tetragonal crystal structure between 6 and 9 mol% of Li, and contains a minor nonperovskite second phase from 6 mol%. A cuboid particle morphology is evident in all cases, though tetragonal KNN-based particles have formed with serrated edges and fractures. The particles are dispersed at 10 vol% in an epoxy matrix to develop both random and dielectrophoretically structured (K,Na,Li)NbO3-epoxy composites. The dielectric constant of the composites appears almost independent of Li content, while the piezoelectric charge constant of structured composites peaks before the polymorphic phase transition, at 3 mol% of Li. The peak in performance can be attributed to the increased primary particle size of the composition in combination with its single phase orthorhombic crystal structure. The enhancement of the energy harvesting figure of merit, derived from substituting 3 mol% of Li in the KNN particulate, makes these composites an interesting choice for flexible energy generators.


 Subject

Energy harvesting
Lead-free ceramics
Piezoelectric materials/properties
Sensors

 To reference this document use:

http://resolver.tudelft.nl/uuid:49b842eb-b6b8-47a2-bf12-d60657dcfb8f

 DOI

https://doi.org/10.1111/jace.14698

 Embargo date

2018-03-01

 ISSN

0002-7820

 Source

Journal of the American Ceramic Society, 100 (3), 1108–1117

 Part of collection

Institutional Repository

 Document type

journal article

 Rights

© 2016 D.B. Deutz, N.T. Mascarenhas, S. van der Zwaag, W.A. Groen
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