lsv電解液氧化分解

lsv電解液氧化分解

Lithium-sulfur(Li-S)batteriesareconsideredaspromisingcandidatesfornext-generationenergystoragesystemsduetotheirhightheoreticalenergydensity,lowcost,andenvironmentalfriendliness.However,thepracticalapplicationofLi-Sbatteriesishinderedbyseveralchallenges,includingthedissolutionandshuttleofpolysulfideintermediates,poorconductivityofsulfur,andlargevolumechangesduringcycling.

ThedevelopmentofsuitableelectrolytesystemsforLi-Sbatteriesiscrucialforovercomingthesechallengesandachievinghigh-performancedevices.Awell-designedelectrolyteshouldhavegoodsolvatingabilityandstabilitytowardspolysulfidespecies,highionicconductivity,andcompatibilitywithboththelithiummetalanodeandthesulfur-basedcathode.

OneofthecommonlyusedelectrolytesystemsforLi-Sbatteriesisbasedonacombinationofalithiumsaltandanorganicsolvent.Thelithiumsaltprovidesthenecessarylithiumionsfortheelectrochemicalreactions,whiletheorganicsolventservesasamediumforiontransport.Somecommonlyusedlithiumsaltsincludelithiumbis(trifluoromethanesulfonyl)imide(LiTFSI),lithiumhexafluorophosphate(LiPF6),andlithiumperchlorate(LiClO4).Thesesaltsarehighlysolubleinorganicsolventsandcanprovidehigh-concentrationlithiumionsforimprovingthespecificcapacityoftheLi-Sbatteries.

Intermsoforganicsolvents,aproticsolventssuchasdimethylsulfoxide(DMSO),N-methyl-2-pyrrolidone(NMP),andtetraethyleneglycoldimethylether(TEGDME)arecommonlyusedinLi-Sbatteries.Thesesolventshavehighdielectricconstantsandgoodsolvatingabilitiestowardslithiumionsandpolysulfidespecies.However,theyalsohavesomedrawbacks,suchashighvolatility,lowflashpoints,andlowthermalstability,whichmayleadtosafetyconcerns.

Toaddressthesesafetyissues,researchershaveexploredtheuseofionicliquid-basedelectrolytesforLi-Sbatteries.Ionicliquidsaremoltensaltsatroomtemperatureandhaveseveraladvantages,includinglowvolatility,wideelectrochemicalwindows,andexcellentthermalstability.SomecommonlyusedionicliquidsforLi-SbatteriesincludeN-methyl-N-propylpyrrolidiniumbis(trifluoromethanesulfonyl)imide(MPPY-TFSI),N-butyl-N-methylpyrrolidiniumbis(trifluoromethanesulfonyl)imide(BMP-TFSI),andN,N-diethyl-N-methyl-N-(2-methoxyethyl)ammoniumbis(trifluoromethanesulfonyl)imide(DEME-TFSI).TheseionicliquidscaneffectivelysuppressthedissolutionandshuttleofpolysulfidespeciesandimprovethecyclingstabilityofLi-Sbatteries.

Inadditiontotheselectionofelectrolytematerials,thedesignofelectrodestructuresshouldalsobeconsideredtoenhancetheperformanceofLi-Sbatteries.Strategiessuchasusingporouscarbonmaterialsashostsforsulfur,modifyingthesurfaceofcarbonmaterialswithfunctionalgroups,andconstructinghybridstructureswithconductivepolymershavebeenexploredtoimprovetheconductivityandstabilityofsulfurcathodes.

Inconclusion,theelectrolytesystemplaysavitalroleintheperformanceofLi-Sbatteries.ThedevelopmentofadvancedelectrolytematerialsandstructuresisessentialforaddressingthechallengesassociatedwithLi-Sbatteriesandpromotingtheirpracticalapplication.Fu