摘要
ParticlebasedmodelsofcompositeanodesareusefultoolsforexploringthebehaviorofSOFCsystems.Aspartofoureffortstodevelopmodelsforunderstandingfuelcells,wehavebeenbuildingmodelsofNi-YSZcompositeanodesusingexperimentallymeasuredparticlesizedistributions.Theobjectivesofthisstudyweretocharacterizethepercolationthresholdandconductivityofthesemodelsincomparisontosimplermonodispersedandbiphasicparticlesizedistributionsfromtheliterature.Wefoundthattheaveragevaluesfortheonsetofpercolationandthemeasuredconductivityofthemodelswithexperimentallymeasuredparticlesizedistributionsaresimilartothoseforthesimpledistributionsandtheexperimentallymeasureddistributions.Foralloftheconfigurationsevaluated,theonsetofpercolationintheNickelphaseoccurredatasolidfractionofNickelbetween20%and25%.ThiscorrespondedalmostexactlytothepointatwhichthecoordinationnumberbetweenNickelphaseparticlesreached2.2.Thesignificantfindingwasthatthevariationinthevaluefortheconductivity,asmeasuredbythestandarddeviationoftheresults,wasseveralordersofmagnitudehigherthanforthesimplersystems.Weexploredthevalidityofourassumptions,specificallytheassumptionofrandomparticleplacement,bybuildingaparticlemodeldirectlyfromFIB-SEMdata.Inthisreconstruction,itwasclearthatthelocationofparticleswasnotrandom.Particlesofthesametypeandsizehadmuchlikelihoodofcontacthigherthanwouldindicatedbyrandomlocation.
出版日期
2013年03月13日(中国期刊网平台首次上网日期,不代表论文的发表时间)