电化学基础双电层模型及其发展

电化学基础双电层模型及其发展一、本文概述Overviewofthisarticle电化学，作为研究电和化学反应相互关系的科学，在能源转换、材料合成、环境保护等诸多领域具有广泛的应用。双电层模型，作为电化学领域的基础理论之一，自其提出以来，对理解电极/溶液界面的电化学行为起到了至关重要的作用。本文旨在全面介绍双电层模型的基本概念、发展历程以及其在现代电化学研究中的应用。文章首先回顾了双电层模型的起源和发展历程，包括Helmholtz模型、Gouy-Chapman模型和Stern模型的提出及其主要思想。随后，文章将重点讨论双电层模型的理论基础，包括电势分布、离子分布以及界面电容等关键参数的计算方法。文章还将介绍双电层模型在电化学研究中的应用，如电极过程动力学、电化学传感器、电催化等领域。文章将展望双电层模型未来的发展方向，包括模型本身的完善、新型电极材料的探索以及其在新能源技术中的应用等。通过本文的阐述，读者将能够深入理解双电层模型的基本原理和应用，为从事电化学相关领域的研究提供理论支持和指导。Electrochemistry,asasciencethatstudiestherelationshipbetweenelectricalandchemicalreactions,hasawiderangeofapplicationsinvariousfieldssuchasenergyconversion,materialsynthesis,andenvironmentalprotection.Thedoublelayermodel,asoneofthefundamentaltheoriesinthefieldofelectrochemistry,hasplayedacrucialroleinunderstandingtheelectrochemicalbehaviorofelectrode/solutioninterfacessinceitsproposal.Thisarticleaimstocomprehensivelyintroducethebasicconcept,developmentprocess,andapplicationofthedoublelayermodelinmodernelectrochemicalresearch.Thearticlefirstreviewstheoriginanddevelopmentofthedoublelayermodel,includingtheHelmholtzmodel,GouyChapmanmodel,andSternmodel,andtheirmainideas.Subsequently,thearticlewillfocusonthetheoreticalbasisofthedoublelayermodel,includingthecalculationmethodsofkeyparameterssuchaspotentialdistribution,iondistribution,andinterfacecapacitance.Thearticlewillalsointroducetheapplicationofthedoublelayermodelinelectrochemicalresearch,suchaselectrodeprocessdynamics,electrochemicalsensors,electrocatalysis,andotherfields.Thearticlewilllookforwardtothefuturedevelopmentdirectionofthedoublelayermodel,includingtheimprovementofthemodelitself,explorationofnewelectrodematerials,anditsapplicationinnewenergytechnologies.Throughtheexplanationinthisarticle,readerswillbeabletodeeplyunderstandthebasicprinciplesandapplicationsofthedoublelayermodel,providingtheoreticalsupportandguidanceforresearchinthefieldofelectrochemistry.二、双电层模型的基本概念Basicconceptsofthedoublelayermodel双电层模型是电化学领域中的一个基本理论模型，它描述了电极与电解质溶液界面处的电荷分布和电场分布情况。这一模型最初由德国物理学家赫尔曼·冯·亥姆霍兹（HermannvonHelmholtz）在19世纪70年代提出，后经多位科学家的完善和发展，逐渐形成了现代电化学中的基本理论框架。Thedoublelayermodelisafundamentaltheoreticalmodelinthefieldofelectrochemistry,whichdescribesthechargedistributionandelectricfielddistributionattheinterfacebetweenelectrodesandelectrolytesolutions.ThismodelwasfirstproposedbyGermanphysicistHermannvonHelmholtzinthe1870s.Afterbeingperfectedanddevelopedbymanyscientists,itgraduallyformedthebasictheoreticalframeworkofmodernelectrochemistry.电极表面电荷：当金属电极浸入电解质溶液中时，由于金属内部电子的逃逸和溶液中离子的吸附，电极表面会形成一层带电荷的薄层，称为电极表面电荷层。Electrodesurfacecharge:Whenametalelectrodeisimmersedinanelectrolytesolution,duetotheescapeofelectronsinsidethemetalandtheadsorptionofionsinthesolution,athinchargedlayerisformedontheelectrodesurface,calledtheelectrodesurfacechargelayer.电解质溶液中的反离子：由于电极表面电荷的存在，电解质溶液中的反离子会受到静电引力的作用而聚集在电极表面附近，形成所谓的反离子层。反离子层的电荷与电极表面电荷相反，从而形成一个双电层结构。Antiionsinelectrolytesolution:Duetothepresenceofsurfacechargesontheelectrode,theantiionsintheelectrolytesolutionwillbeattractedbyelectrostaticforcesandgatherneartheelectrodesurface,formingaso-calledantiionlayer.Thechargeofthecounterionlayerisoppositetothesurfacechargeoftheelectrode,formingadoublelayerstructure.电势差与电场：双电层模型中，电极表面与电解质溶液之间存在一定的电势差，形成了所谓的双电层电势（或称为电极电势）。这一电势差导致双电层内部产生电场，对电解质溶液中的离子产生驱动力，从而影响离子的迁移和分布。Potentialdifferenceandelectricfield:Inthedoublelayermodel,thereisacertainpotentialdifferencebetweentheelectrodesurfaceandtheelectrolytesolution,formingtheso-calleddoublelayerpotential(alsoknownaselectrodepotential).Thispotentialdifferencecausesanelectricfieldtobegeneratedinsidethedoublelayer,whichdrivestheionsintheelectrolytesolution,therebyaffectingthemigrationanddistributionofions.电极反应与双电层：当电极上发生氧化还原反应时，电子的转移会导致电极表面电荷的变化，进而影响到双电层的结构和性质。因此，双电层模型是研究电极反应动力学和机理的重要理论基础。Electrodereactionanddoublelayer:Whenanoxidation-reductionreactionoccursontheelectrode,thetransferofelectronscausesachangeinthesurfacechargeoftheelectrode,whichinturnaffectsthestructureandpropertiesofthedoublelayer.Therefore,thedoublelayermodelisanimportanttheoreticalbasisforstudyingthekineticsandmechanismsofelectrodereactions.随着科学技术的进步和实验手段的发展，人们对双电层模型的认识不断深入和完善。例如，现代研究表明，双电层结构并非简单的平板电容器模型，而是具有更为复杂的空间分布和动态行为。然而，作为电化学领域的基础理论之一，双电层模型仍然对于理解电极过程、设计电化学器件和优化电化学反应条件等方面具有重要意义。Withtheprogressofscienceandtechnologyandthedevelopmentofexperimentalmethods,people'sunderstandingofthedoublelayermodelisconstantlydeepeningandimproving.Forexample,modernresearchhasshownthatthedoublelayerstructureisnotasimplemodelofaflatcapacitor,butratherhasamorecomplexspatialdistributionanddynamicbehavior.However,asoneofthefundamentaltheoriesinthefieldofelectrochemistry,thedoublelayermodelisstillofgreatsignificanceforunderstandingelectrodeprocesses,designingelectrochemicaldevices,andoptimizingelectrochemicalreactionconditions.三、双电层模型的发展历程TheDevelopmentHistoryoftheDoubleLayerModel自19世纪末以来，双电层现象一直是电化学领域的研究热点。双电层模型的发展历程，可以说是对界面电荷分布和电位分布理解不断深化的过程。这一历程中，涌现出了多位杰出的科学家，他们通过不懈的努力和创新，推动了双电层理论的逐步完善。Sincethelate19thcentury,thedoublelayerphenomenonhasbeenaresearchhotspotinthefieldofelectrochemistry.Thedevelopmentprocessofthedoublelayermodelcanbesaidtobeadeepeningunderstandingoftheinterfacechargedistributionandpotentialdistribution.Duringthisprocess,multipleoutstandingscientistsemergedwho,throughunremittingeffortsandinnovation,promotedthegradualimprovementofthedoublelayertheory.早期的双电层模型以Helmholtz的双电层模型为代表，该模型假设在电极和电解质溶液的界面上，电荷分布是均匀且紧密的。然而，随着研究的深入，科学家们发现Helmholtz模型无法解释一些实验现象，如电极表面的电位分布和电容行为。EarlydoublelayermodelswererepresentedbyHelmholtz'sdoublelayermodel,whichassumedthatthechargedistributionwasuniformandtightattheinterfacebetweentheelectrodeandelectrolytesolution.However,asresearchdeepens,scientistshavefoundthattheHelmholtzmodelcannotexplainsomeexperimentalphenomena,suchasthepotentialdistributionandcapacitancebehaviorontheelectrodesurface.随后，Gouy和Chapman提出了扩散双电层模型，该模型考虑了电解质离子在溶液中的热运动和扩散作用，认为电荷在界面上的分布是扩散的。这一模型更好地解释了电位分布和电容行为，但仍存在一些问题，如无法准确描述电极表面的电荷分布。Subsequently,GouyandChapmanproposedthediffusiondoublelayermodel,whichtakesintoaccountthethermalmotionanddiffusionofelectrolyteionsinsolution,andassumesthatthedistributionofchargesattheinterfaceisdiffusion.Thismodelcanbetterexplainthepotentialdistributionandcapacitancebehavior,buttherearestillsomeproblems,suchastheinabilitytoaccuratelydescribethechargedistributionontheelectrodesurface.为了克服扩散双电层模型的不足，Stern在20世纪初提出了修正的Gouy-Chapman模型，即Stern模型。该模型将双电层分为紧密层和扩散层两部分，紧密层紧邻电极表面，电荷分布较为紧密，而扩散层则位于紧密层外侧，电荷分布呈现扩散状。Stern模型更加符合实验事实，为后续的研究奠定了坚实基础。Inordertoovercometheshortcomingsofthediffusiondoublelayermodel,SternproposedamodifiedGouyChapmanmodel,alsoknownastheSternmodel,intheearly20thcentury.Thismodeldividesthedoublelayerintotwoparts:acompactlayerandadiffusionlayer.Thecompactlayerisadjacenttotheelectrodesurface,andthechargedistributionisrelativelytight,whilethediffusionlayerislocatedontheoutersideofthecompactlayer,andthechargedistributionshowsadiffusionpattern.TheSternmodelismoreinlinewithexperimentalfactsandlaysasolidfoundationforsubsequentresearch.近年来，随着计算化学和分子模拟技术的快速发展，双电层模型的研究进入了一个新的阶段。科学家们通过分子模拟方法，可以更加精确地描述电极表面和电解质溶液之间的相互作用，揭示双电层结构的微观细节。这些研究不仅深化了我们对双电层现象的理解，也为电化学领域的其他研究提供了有力支持。Inrecentyears,withtherapiddevelopmentofcomputationalchemistryandmolecularsimulationtechnology,thestudyofdoublelayermodelshasenteredanewstage.Scientistscanmoreaccuratelydescribetheinteractionbetweentheelectrodesurfaceandelectrolytesolutionthroughmolecularsimulationmethods,revealingthemicroscopicdetailsofthedoublelayerstructure.Thesestudiesnotonlydeepenourunderstandingofthedoublelayerphenomenon,butalsoprovidestrongsupportforotherresearchinthefieldofelectrochemistry.双电层模型的发展历程是一个不断修正和完善的过程。从Helmholtz模型到Gouy-Chapman模型，再到Stern模型，以及现代的分子模拟方法，每一步的进展都凝聚了科学家们的智慧和努力。未来，随着科学技术的不断进步，我们有理由相信双电层模型将会得到更加深入的研究和发展。Thedevelopmentprocessofthedoublelayermodelisacontinuousprocessofrevisionandimprovement.FromtheHelmholtzmodeltotheGouyChapmanmodel,totheSternmodel,andmodernmolecularsimulationmethods,eachstepofprogresshascondensedthewisdomandeffortsofscientists.Inthefuture,withthecontinuousprogressofscienceandtechnology,wehavereasontobelievethatthedoublelayermodelwillreceivemorein-depthresearchanddevelopment.四、现代双电层模型的研究进展Researchprogressonmoderndoublelayermodels随着科学技术的不断发展，电化学领域对双电层模型的理解和认识也在逐步深化。现代双电层模型的研究进展主要体现在对界面结构和性质的深入研究、新技术的应用以及模型优化和修正等方面。Withthecontinuousdevelopmentofscienceandtechnology,theunderstandingandrecognitionofthedoublelayermodelinthefieldofelectrochemistryaregraduallydeepening.Theresearchprogressofmoderndoublelayermodelsismainlyreflectedinin-depthresearchoninterfacestructureandproperties,applicationofnewtechnologies,andmodeloptimizationandcorrection.界面结构和性质的深入研究：近年来，科研人员运用先进的表面科学技术，如原子力显微镜（AFM）、扫描隧道显微镜（STM）等，对电极/溶液界面的结构和性质进行了更为精细的研究。这些技术能够直接观测到界面上的原子排布、电荷分布以及溶剂分子的行为，为双电层模型的修正提供了实验依据。Indepthresearchoninterfacestructureandproperties:Inrecentyears,researchershaveutilizedadvancedsurfacesciencetechniquessuchasatomicforcemicroscopy(AFM),scanningtunnelingmicroscopy(STM),etc.toconductmoredetailedstudiesonthestructureandpropertiesofelectrode/solutioninterfaces.Thesetechnologiescandirectlyobservetheatomicarrangement,chargedistribution,andsolventmoleculebehaviorattheinterface,providingexperimentalbasisforthecorrectionofthedoublelayermodel.新技术的应用：随着纳米科学和纳米技术的兴起，双电层模型在纳米尺度下的表现引起了广泛关注。科研人员开始研究纳米颗粒、纳米线等纳米材料在电化学过程中的双电层行为，这对于理解纳米尺度下的电化学过程以及设计高性能的纳米电化学器件具有重要意义。Theapplicationofnewtechnologies:Withtheriseofnanoscienceandnanotechnology,theperformanceofdoublelayermodelsatthenanoscalehasattractedwidespreadattention.Researchershavebeguntostudythedoublelayerbehaviorofnanomaterialssuchasnanoparticlesandnanowiresduringelectrochemicalprocesses,whichisofgreatsignificanceforunderstandingtheelectrochemicalprocessesatthenanoscaleanddesigninghigh-performancenanoelectrochemicaldevices.模型优化和修正：随着实验技术的进步和理论研究的深入，传统的双电层模型也在不断得到优化和修正。例如，考虑到溶剂分子在界面上的作用，科研人员提出了溶剂化离子模型，该模型能够更好地描述溶剂分子对双电层结构的影响。还有一些模型考虑了电极表面的粗糙度、电荷的不均匀分布等因素，使得模型更加接近实际情况。Modeloptimizationandcorrection:Withtheadvancementofexperimentaltechnologyandthedeepeningoftheoreticalresearch,traditionaldouble-layermodelsarealsoconstantlybeingoptimizedandcorrected.Forexample,consideringtheroleofsolventmoleculesattheinterface,researchershaveproposedthesolvationionmodel,whichcanbetterdescribetheinfluenceofsolventmoleculesonthedoublelayerstructure.Somemodelsalsoconsiderfactorssuchastheroughnessoftheelectrodesurfaceandtheunevendistributionofcharges,makingthemclosertotheactualsituation.计算模拟方法的应用：随着计算化学和计算物理的快速发展，越来越多的科研人员开始运用分子动力学模拟、量子化学计算等方法来研究双电层模型。这些方法能够在原子或分子尺度上模拟电化学过程，为双电层模型的验证和优化提供了有力工具。Theapplicationofcomputationalsimulationmethods:Withtherapiddevelopmentofcomputationalchemistryandphysics,moreandmoreresearchersarestartingtousemoleculardynamicssimulations,quantumchemicalcalculations,andothermethodstostudythedoublelayermodel.Thesemethodscansimulateelectrochemicalprocessesattheatomicormolecularscale,providingpowerfultoolsforverifyingandoptimizingthedoublelayermodel.现代双电层模型的研究进展体现在多个方面，包括界面结构和性质的深入研究、新技术的应用、模型优化和修正以及计算模拟方法的应用等。这些进展不仅加深了我们对双电层模型的理解，也为电化学领域的发展提供了新的思路和方法。未来，随着科学技术的不断进步，我们有望对双电层模型有更加深入和全面的认识。Theresearchprogressofmoderndoublelayermodelsisreflectedinmultipleaspects,includingin-depthresearchoninterfacestructureandproperties,applicationofnewtechnologies,modeloptimizationandcorrection,andapplicationofcomputationalsimulationmethods.Theseadvancesnotonlydeepenourunderstandingofthedoublelayermodel,butalsoprovidenewideasandmethodsforthedevelopmentoftheelectrochemicalfield.Inthefuture,withthecontinuousprogressofscienceandtechnology,weareexpectedtohaveadeeperandmorecomprehensiveunderstandingofthedoublelayermodel.五、双电层模型在电化学领域的应用ApplicationofDoubleLayerModelinElectrochemicalField双电层模型自提出以来，就在电化学领域发挥着至关重要的作用。这一模型不仅帮助我们深入理解了电极与电解质溶液界面的电化学性质，而且在实际的电化学过程中也具有广泛的应用。Sinceitsproposal,thedoublelayermodelhasplayedacrucialroleinthefieldofelectrochemistry.Thismodelnotonlyhelpsustounderstandtheelectrochemicalpropertiesoftheinterfacebetweenelectrodeandelectrolytesolution,butalsohasawiderangeofapplicationsinpracticalelectrochemicalprocesses.双电层模型在电化学腐蚀的研究中起到了关键作用。通过双电层模型，我们可以对金属在电解质溶液中的腐蚀过程进行定量描述，从而预测和控制腐蚀速率，为金属防护提供理论支持。Thedoublelayermodelplaysacrucialroleinthestudyofelectrochemicalcorrosion.Throughthedoublelayermodel,wecanquantitativelydescribethecorrosionprocessofmetalsinelectrolytesolutions,predictandcontrolthecorrosionrate,andprovidetheoreticalsupportformetalprotection.双电层模型在电化学储能技术中也有重要应用。例如，在锂离子电池、超级电容器等电化学储能器件中，双电层模型可以帮助我们理解电极材料的充放电过程，优化电极结构设计，提高储能器件的性能。Thedoublelayermodelalsohasimportantapplicationsinelectrochemicalenergystoragetechnology.Forexample,inelectrochemicalenergystoragedevicessuchaslithium-ionbatteriesandsupercapacitors,thedoublelayermodelcanhelpusunderstandthecharginganddischargingprocessofelectrodematerials,optimizeelectrodestructuredesign,andimprovetheperformanceofenergystoragedevices.双电层模型还在电化学合成、电催化等领域发挥着重要作用。通过调控双电层结构，我们可以实现对电化学反应的选择性控制，合成出具有特定结构和性质的材料，或者提高电催化反应的活性。Thedoublelayermodelalsoplaysanimportantroleinfieldssuchaselectrochemicalsynthesisandelectrocatalysis.Byregulatingthedoublelayerstructure,wecanachieveselectivecontrolofelectrochemicalreactions,synthesizematerialswithspecificstructuresandproperties,orimprovetheactivityofelectrocatalyticreactions.随着科学技术的不断发展，双电层模型也在不断发展和完善。例如，近年来，研究者们开始关注纳米尺度下的双电层行为，探索纳米材料在电化学过程中的新现象和新机制。这些研究不仅有助于我们更深入地理解电化学过程，也为电化学领域的发展提供了新的机遇和挑战。Withthecontinuousdevelopmentofscienceandtechnology,thedoublelayermodelisalsoconstantlyevolvingandimproving.Forexample,inrecentyears,researchershavebeguntofocusonthedoublelayerbehavioratthenanoscale,exploringnewphenomenaandmechanismsofnanomaterialsinelectrochemicalprocesses.Thesestudiesnotonlyhelpusgainadeeperunderstandingofelectrochemicalprocesses,butalsoprovidenewopportunitiesandchallengesforthedevelopmentofthefieldofelectrochemistry.双电层模型在电化学领域的应用广泛而深入，它不仅为我们提供了理解和控制电化学过程的理论基础，也为电化学领域的发展提供了强大的推动力。未来，随着科学技术的不断进步，双电层模型的应用将会更加广泛和深入。Thedoublelayermodelhasbeenwidelyanddeeplyappliedinthefieldofelectrochemistry.Itnotonlyprovidesuswithatheoreticalbasisforunderstandingandcontrollingelectrochemicalprocesses,butalsoprovidesastrongdrivingforceforthedevelopmentoftheelectrochemicalfield.Inthefuture,withthecontinuousprogressofscienceandtechnology,theapplicationofthedoublelayermodelwillbemoreextensiveandin-depth.六、双电层模型的挑战与未来发展方向Thechallengesandfuturedevelopmentdirectionsofthedoublelayermodel尽管双电层模型在电化学领域取得了显著的成果，但它仍然面临着一些挑战和限制。该模型在描述复杂界面现象时可能显得过于简化，忽略了界面上的动态过程和多种相互作用。双电层模型通常基于理想化的假设，如平滑的界面和均匀的电荷分布，这在实际情况中可能并不总是成立。Althoughthedoublelayermodelhasachievedsignificantresultsinthefieldofelectrochemistry,itstillfacessomechallengesandlimitations.Thismodelmayappearoverlysimplifiedindescribingcomplexinterfacephenomena,ignoringthedynamicprocessesandvariousinteractionsontheinterface.Thedoublelayermodelisusuallybasedonidealizedassumptionssuchassmoothinterfacesanduniformchargedistribution,whichmaynotalwaysbetrueinpracticalsituations.未来，双电层模型的发展将需要在以下几个方面取得进展。需要更加深入地理解界面上的动态过程和多种相互作用，以建立更加全面和准确的模型。这可能需要结合先进的实验技术和计算方法，以揭示界面上发生的微观过程。Inthefuture,thedevelopmentofthedoublelayermodelwillrequireprogressinthefollowingareas.Adeeperunderstandingofthedynamicprocessesandvariousinteractionsontheinterfaceisneededtoestablishamorecomprehensiveandaccuratemodel.Thismayrequirethecombinationofadvancedexperimentaltechniquesandcomputationalmethodstorevealthemicroscopicprocessesoccurringattheinterface.双电层模型需要考虑到更多实际条件，如界面的粗糙度、电荷分布的不均匀性、以及溶液中离子的种类和浓度等。这将有助于提高模型的预测能力和适用性，使其能够更好地描述实际电化学体系的行为。Thedoublelayermodelneedstoconsidermorepracticalconditions,suchasinterfaceroughness,unevenchargedistribution,andthetypeandconcentrationofionsinthesolution.Thiswillhelpimprovethepredictiveabilityandapplicabilityofthemodel,enablingittobetterdescribethebehaviorofactualelectrochemicalsystems.随着电化学领域的不断发展，双电层模型也需要不断更新和完善。例如，可以考虑将纳米材料、电解质溶液等新型电化学体系的特性纳入模型中，以扩展其应用范围。Withthecontinuousdevelopmentoftheelectrochemicalfield,thedoublelayermodelalsoneedstobeconstantlyupdatedandimproved.Forexample,itispossibletoconsiderincorporatingthecharacteristicsofnewelectrochemicalsystemssuchasnanomaterialsandelectrolytesolutionsintothemodeltoexpandtheirapplicationscope.双电层模型作为电化学领域的基础模型之一，仍然具有广阔的发展空间和挑战。通过不断深入研究和完善模型，我们有望更好地理解电化学现象的本质和规律，为电化学领域的发展做出更大的贡献。Thedoublelayermodel,asoneofthefundamentalmodelsinthefieldofelectrochemistry,stillhasbroaddevelopmentspaceandchallenges.Throughcontinuousin-depthresearchandimprovementofmodels,weareexpectedtobetterunderstandtheessenceandlawsofelectrochemicalphenomena,andmakegreatercontributionstothedevelopmentoftheelectrochemicalfield.七、结论Conclusion随着科学技术的不断发展，电化学领域的研究日益深入，双电层模型作为电化学的基础理论之一，其重要性不言而喻。本文详细探讨了双电层模型的发展历程，从最初的Helmholtz模型到后来的Gouy-Chapman模型，再到Stern模型，每一个阶段都是对前人理论的继承与发展，都是对双电层现象更深入的理解。Withthecontinuousdevelopmentofscienceandtechnology,researchinthefieldofelectrochemistryisbecomingincreasinglyin-depth.Asoneofthefundamentaltheoriesofelectrochemistry,theimportanceofthedoublelayermodelisself-evident.Thisarticleexploresindetailthedevelopmentprocessofthedoublelayermodel,fromtheinitialHelmholtzmodeltothelaterGouyChapmanmodel,andthentotheSternmodel.Eachstageisaninheritanceanddevelopmentofprevioustheories,andadeeperunderstandingofthedoublelayerphenomenon.Helmholtz模型作为最早的双电层模型，虽然简单直观，但其假设过于理想化，无法解释一些实验现象。Gouy-Chapman模型通过引入扩散双电层的概念，使得模型更加接近实际情况，但其忽略了离子大小和溶剂分子的作用。而Stern模型则进一步细化了双电层结构，将双电层分为紧密层和扩散层，更好地解释了实验数据。TheHelmholtzmodel,astheearliestdoublelayermodel,althoughsimpleandintuitive,itsassumptionsar