Tuneable conductivity at extreme electric fields in ZnO tetrapod-silicone composites for high-voltage power cable insulation
Artikel i vetenskaplig tidskrift, 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.
Författare
Helena Greijer
Hitachi
Nicola Mirotta
Consiglio Nazionale delle Ricerche (CNR)
E. Treossi
Consiglio Nazionale delle Ricerche (CNR)
Filippo Valorosi
Consiglio Nazionale delle Ricerche (CNR)
Fabian Schütt
Christian-Albrechts-Universität zu Kiel
Leonard Siebert
Christian-Albrechts-Universität zu Kiel
Yogendra Kumar Mishra
Syddansk Universitet
Rainer Adelung
Christian-Albrechts-Universität zu Kiel
Vincenzo Palermo
Consiglio Nazionale delle Ricerche (CNR)
Chalmers, Industri- och materialvetenskap, Material och tillverkning
Henrik Hillborg
Hitachi
Scientific Reports
2045-2322 (ISSN) 20452322 (eISSN)
Vol. 12 1 6035-Ämneskategorier (SSIF 2011)
Materialkemi
Annan elektroteknik och elektronik
Den kondenserade materiens fysik
DOI
10.1038/s41598-022-09966-4
PubMed
35410428