ProtonconductivityofNafion membranes,thekeyfeaturefortheirapplicationinprotonexchange

membrane fuelcells,hasbeenreportedinmanyworks.Itbecomesnecessarytoassemblethesemassive

reports topresentanoverviewforfurtherdevelopmentguidelines.Weapplyanexhaustivesearchand

retrieve3539recordsfrom310originalreports.Theserecordsaredumpedintoadatabaseandasta-

tistical analysisiscarriedouttoestablishtheoverview.Thehistogram,thetrend,thetemperature,the

relativehumidityand fillers relatedtotheprotonconductivityofNafion membranesareinvestigated.

There isnotalwayspositiveprogressinrecent13yearstoimprovetheprotonconductivityofNafion

membranes. Theprotonconductivitycanbe fitted usingasimpleexponentiallyincreasingfunctionfor

relativehumiditydependence,andtheArrheniusequationfortemperaturedependencewithacceptable

correlation confidence. WatercontentsinmembranesfromvaporcanbewelldepictedbyBrunauer–

Emmett–Tellerequation,andtheyhavereasonablecorrelationwithprotonconductivities.Inorganic

fillers usuallyprovidebetterenhancementinprotonconductivitythanorganic fillers, whichisaresultof

the formerhavebetterwater-holdingcapability.Fillersthatcanfacilitatetheformationofpercolated

waterchannelwithlesstortuosityhavehighprobabilitytosignificantly improvetheprotonconductivity

of Nafion membranes.