Tuneable conductivity at extreme electric fields in ZnO tetrapod-silicone composites for high-voltage power cable insulation
Journal article, 2022

Resistive Field Grading Materials (RFGM) are used in critical regions in the electrical insulation system of high-voltage direct-current cable systems. Here, we describe a novel type of RFGM, based on a percolated network of zinc oxide (ZnO) tetrapods in a rubber matrix. The electrical conductivity of the composite increases by a factor of 108 for electric fields > 1 kV mm-1, as a result of the highly anisotropic shape of the tetrapods and their significant bandgap (3.37 eV). We demonstrate that charge transport at fields < 1 kV mm-1 is dominated by thermally activated hopping of charge carriers across spatially, as well as energetically, localized states at the ZnO-polymer interface. At higher electric fields (> 1 kV mm-1) band transport in the semiconductive tetrapods triggers a large increase in conductivity. These geometrically enhanced ZnO semiconductors outperform standard additives such as SiC particles and ZnO micro varistors, providing a new class of additives to achieve variable conductivity in high-voltage cable system applications.

Author

Helena Greijer

Hitachi, Ltd.

Nicola Mirotta

Institute for organic syntheses and photoreactivity (ISOF-CNR)

E. Treossi

Institute for organic syntheses and photoreactivity (ISOF-CNR)

Filippo Valorosi

Institute for organic syntheses and photoreactivity (ISOF-CNR)

Fabian Schütt

University of Kiel

Leonard Siebert

University of Kiel

Yogendra Kumar Mishra

University of Southern Denmark

Rainer Adelung

University of Kiel

Vincenzo Palermo

Institute for organic syntheses and photoreactivity (ISOF-CNR)

Chalmers, Industrial and Materials Science, Materials and manufacture

Henrik Hillborg

Hitachi, Ltd.

Scientific Reports

2045-2322 (ISSN) 20452322 (eISSN)

Vol. 12 1 6035-

Subject Categories

Materials Chemistry

Other Electrical Engineering, Electronic Engineering, Information Engineering

Condensed Matter Physics

DOI

10.1038/s41598-022-09966-4

PubMed

35410428

More information

Latest update

11/4/2022