OPTIMIZATION OF FILM CAPACITORS: A NEW COSMOS OR JUST A CHAOS

Odysseas Gkionis-Konstantatos

doi:10.21996/3658bd87-214b-46c0-9469-df797ede7772

OPTIMIZATION OF FILM CAPACITORS: A NEW COSMOS OR JUST A CHAOS

Odysseas Gkionis-Konstantatos^*

^*Kontaktforfatter

Publikation: Afhandling › Ph.d.-afhandling

77 Downloads (Pure)

Abstract

Inden for grøn energiteknologi er behovet for kondensatorer, der kan fungere ved forhøjede elektriske felter og høje temperaturer, blevet stadig mere påtrængende. Litteraturanalyser fremhæver industrien præference for polymérfilm-kondensatorer, hvor biaxialt orienteret polypropylen (BOPP) fortsat er den førende dielektriske film på grund af dens effektive selvhelings-evne og omkostningseffektivitet. Dog kræver dens begrænsede energitæthed og driftstemperaturområde optimering for at imødekomme stræben efter en universel kondensatorteknologi.

På trods af mere end 70 års industriel anvendelse giver metalliserede polypropylenfilm-kondensatorer (MPPFC’er) stadig nye indsigter. Deres delvist uforståede potentiale skyldes BOPP’s semicrystallinske natur, som let kan ændres og dermed frembringe forskellig dielektrisk adfærd. Denne afhandling undersøger ydeevnen af ultratynde 1,9 µm BOPP-film, når de anvendes i kondensatorsystemer.

Det første studie undersøgte effekten af reduceret dielektrisk tykkelse ved hjælp af enkelt- og dobbeltlagsprøver. Tyndere film viste lavere nedbrydningsstyrke, større clearing-steder og større variation i efter-nedbrudskapacitans, hvilket understreger behovet for alternative optimeringsstrategier. For at imødekomme dette blev et multilagsdesign med wolframoxid (WO) og aluminium-nitrid (AlN) implementeret. Dette forbedrede varmeafledning, øgede nedbrydningsstyrken ved 63,2% u-pålidelighedsniveauet og reducerede variationen i clearing-steder, hvilket blev bekræftet gennem termisk billeddannelse og simuleringer.

Parallelt viste varmebehandling af BOPP-film før kondensatormontage sig at fremme molekylær kædeorientering, øge krystalliniteten, forbedre overflademorfologi og styrke vedhæftningen af metallisering. Disse ændringer resulterede i højere smeltepunkt, bedre termisk stabilitet og en afvejning mellem duktilitet og styrke med reduceret mekanisk variation. Elektrisk viste de anløbne film højere nedbrydningsstyrke på tværs af alle u-pålidelighedsniveauer, mindre og mere ensartede nedbrudssteder samt stabil kapacitansbevarelse, også verificeret i dobbeltlagskonfigurationer kondensatorstak.

Samlet demonstrerer resultaterne, at multilagsintegration og varmebehandling udgør effektive veje til at imødegå pålidelighedsudfordringerne ved ultratynd BOPP og tilbyder et fundament for udviklingen af næste generations MPPFC’er. Resultaterne afspejler desuden både industrielle og laboratoriemæssige praksisser og giver nye indsigter til fremtidig kondensatoroptimering.

Originalsprog	Engelsk
Bevilgende institution	Syddansk Universitet
Vejledere/rådgivere	Tavares, Luciana, Hovedvejleder Ebel, Thomas, Bivejleder Greenbank, William, Bivejleder
Dato for forsvar	14. nov. 2025
Udgiver	Syddansk Universitet. Det Tekniske Fakultet
DOI	https://doi.org/10.21996/3658bd87-214b-46c0-9469-df797ede7772
Status	Udgivet - 2. okt. 2025

Dokumenter og links

10.21996/3658bd87-214b-46c0-9469-df797ede7772

PhD_Thesis_Odysseas_Gkionis_KonstantatosForlagets udgivne version, 36,8 MB

SDU link

Tjek adgangen til materialet i Syddansk Universitetsbiblioteks søgemaskine

2 Tidsskriftartikel

Investigating the role of flow plate surface roughness in polymer electrolyte membrane fuel cells with the use of multiphysics simulations
Gkionis-Konstantatos, O., Tavares, L. & Ebel, T., aug. 2024, I: Batteries. 10, 8, 22 s., 276.
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

Åben adgang
Fil
88 Downloads (Pure)
Nanoscale thinning of metal-coated polypropylene films by Helium-ion irradiation
Neupane, S., Chiriaev, S., Greenbank, W., Gkionis-Konstantatos, O., Leissner, T., Ebel, T. & Tavares, L., 18. okt. 2023, I: Power Electronic Devices and Components. 6, 6 s., 100046.
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

Åben adgang
Fil
105 Downloads (Pure)

Citationsformater

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title = "OPTIMIZATION OF FILM CAPACITORS: A NEW COSMOS OR JUST A CHAOS",

abstract = "In the realm of green energy technologies, the demand for capacitors capable of operating under elevated electric fields and high temperatures has become increasingly urgent. Literature analyses highlight the industrial preference for polymer film capacitors, with biaxially oriented polypropylene (BOPP) remaining the state-of-the-art dielectric due to its efficient self-clearing capability and cost-effectiveness. However, its inherently low energy density and limited operating temperature range necessitate optimization to meet the ongoing pursuit of a universal capacitor technology. Despite over 70 years of industrial maturity, metallized polypropylene film capacitors (MPPFCs) continue to reveal new insights. Their partially understood potential arises from the semicrystalline nature of BOPP, which can be readily altered to yield different dielectric behaviors. This thesis investigates the performance of ultrathin 1.9 µm BOPP films when employed in capacitor systems. The first study examined the effect of reduced dielectric thickness using single- and double-layer capacitor samples. Thinner films were found to lower breakdown strength, enlarge clearing sites, and increase variability in post-breakdown capacitance, underscoring the need for alternative optimization approaches. To address this, a multilayer design integrating tungsten oxide (WO3 ) and aluminum nitride (AlN) was implemented, which improved heat dissipation, enhanced breakdown strength at the 63.2\% unreliability level, and reduced clearing site variability, as confirmed by thermal imaging and simulations. In parallel, thermal annealing of BOPP films prior to capacitor assembly was shown to promote molecular chain alignment, increase crystallinity, improve surface morphology, and strengthen metallization adhesion. These modifications resulted in higher melting points, improved thermal stability, and a ductility{\textendash}strength trade-off with reduced mechanical variability. Electrically, annealed films demonstrated higher breakdown strength across all unreliability levels, smaller and more uniform breakdown sites, and stable capacitance retention, verified also in double-layer capcitor stack configurations. Collectively, these findings demonstrate that multilayer integration and heat treatment provide effective pathways to mitigate the reliability challenges of ultrathin BOPP, offering a framework for advancing next-generation MPPFCs. The outcomes further reflect on both industrial and laboratory practices, providing new insights for future capacitor optimization.",

author = "Odysseas Gkionis-Konstantatos",

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N2 - In the realm of green energy technologies, the demand for capacitors capable of operating under elevated electric fields and high temperatures has become increasingly urgent. Literature analyses highlight the industrial preference for polymer film capacitors, with biaxially oriented polypropylene (BOPP) remaining the state-of-the-art dielectric due to its efficient self-clearing capability and cost-effectiveness. However, its inherently low energy density and limited operating temperature range necessitate optimization to meet the ongoing pursuit of a universal capacitor technology. Despite over 70 years of industrial maturity, metallized polypropylene film capacitors (MPPFCs) continue to reveal new insights. Their partially understood potential arises from the semicrystalline nature of BOPP, which can be readily altered to yield different dielectric behaviors. This thesis investigates the performance of ultrathin 1.9 µm BOPP films when employed in capacitor systems. The first study examined the effect of reduced dielectric thickness using single- and double-layer capacitor samples. Thinner films were found to lower breakdown strength, enlarge clearing sites, and increase variability in post-breakdown capacitance, underscoring the need for alternative optimization approaches. To address this, a multilayer design integrating tungsten oxide (WO3 ) and aluminum nitride (AlN) was implemented, which improved heat dissipation, enhanced breakdown strength at the 63.2% unreliability level, and reduced clearing site variability, as confirmed by thermal imaging and simulations. In parallel, thermal annealing of BOPP films prior to capacitor assembly was shown to promote molecular chain alignment, increase crystallinity, improve surface morphology, and strengthen metallization adhesion. These modifications resulted in higher melting points, improved thermal stability, and a ductility–strength trade-off with reduced mechanical variability. Electrically, annealed films demonstrated higher breakdown strength across all unreliability levels, smaller and more uniform breakdown sites, and stable capacitance retention, verified also in double-layer capcitor stack configurations. Collectively, these findings demonstrate that multilayer integration and heat treatment provide effective pathways to mitigate the reliability challenges of ultrathin BOPP, offering a framework for advancing next-generation MPPFCs. The outcomes further reflect on both industrial and laboratory practices, providing new insights for future capacitor optimization.

AB - In the realm of green energy technologies, the demand for capacitors capable of operating under elevated electric fields and high temperatures has become increasingly urgent. Literature analyses highlight the industrial preference for polymer film capacitors, with biaxially oriented polypropylene (BOPP) remaining the state-of-the-art dielectric due to its efficient self-clearing capability and cost-effectiveness. However, its inherently low energy density and limited operating temperature range necessitate optimization to meet the ongoing pursuit of a universal capacitor technology. Despite over 70 years of industrial maturity, metallized polypropylene film capacitors (MPPFCs) continue to reveal new insights. Their partially understood potential arises from the semicrystalline nature of BOPP, which can be readily altered to yield different dielectric behaviors. This thesis investigates the performance of ultrathin 1.9 µm BOPP films when employed in capacitor systems. The first study examined the effect of reduced dielectric thickness using single- and double-layer capacitor samples. Thinner films were found to lower breakdown strength, enlarge clearing sites, and increase variability in post-breakdown capacitance, underscoring the need for alternative optimization approaches. To address this, a multilayer design integrating tungsten oxide (WO3 ) and aluminum nitride (AlN) was implemented, which improved heat dissipation, enhanced breakdown strength at the 63.2% unreliability level, and reduced clearing site variability, as confirmed by thermal imaging and simulations. In parallel, thermal annealing of BOPP films prior to capacitor assembly was shown to promote molecular chain alignment, increase crystallinity, improve surface morphology, and strengthen metallization adhesion. These modifications resulted in higher melting points, improved thermal stability, and a ductility–strength trade-off with reduced mechanical variability. Electrically, annealed films demonstrated higher breakdown strength across all unreliability levels, smaller and more uniform breakdown sites, and stable capacitance retention, verified also in double-layer capcitor stack configurations. Collectively, these findings demonstrate that multilayer integration and heat treatment provide effective pathways to mitigate the reliability challenges of ultrathin BOPP, offering a framework for advancing next-generation MPPFCs. The outcomes further reflect on both industrial and laboratory practices, providing new insights for future capacitor optimization.

U2 - 10.21996/3658bd87-214b-46c0-9469-df797ede7772

DO - 10.21996/3658bd87-214b-46c0-9469-df797ede7772

M3 - Ph.D. thesis

PB - Syddansk Universitet. Det Tekniske Fakultet

ER -

OPTIMIZATION OF FILM CAPACITORS: A NEW COSMOS OR JUST A CHAOS

Abstract

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Relaterede publikationer

Investigating the role of flow plate surface roughness in polymer electrolyte membrane fuel cells with the use of multiphysics simulations

Nanoscale thinning of metal-coated polypropylene films by Helium-ion irradiation

Citationsformater