PDF Publication Title:
Text from PDF Page: 029
US 9,905,856B1 24 maybepreferablyemployed.Thisnon-aqueoussolventis lithiumtrifluoro-metasulfonate(LiCF2S03)andbis-trifluo advantageousinthatitis(a)stableagainstanegative romethylsulfonylimidelithium[LiN(CF2SO2)2].Among electrodecontainingacarbonaceousmaterialwelldevel- them,LiPF.,LiBF.andLiN(CFSO,),arepreferred. opedingraphitestructure;(b)efectiveinsuppressingthe10 Thecontentofaforementionedelectrolyticsaltsinthe reductiveoroxidativedecompositionofelectrolyte;and(c) non-aqueoussolventispreferablygreaterthan2.5M(mol/ highinconductivity.Anon-aqueouselectrolytesolelycom- 1),morepreferably>3.0M,furthermorepreferably>5.0M, posedofethylenecarbonate(EC)isadvantageousinthatit stilmorepreferably>7.0M,andmostpreferably>10M.An isrelativelystableagainstdecompositionthroughareduc- electrolytecontainingahigherconcentrationofalkalimetal tionby agraphitizedcarbonaceousmaterial.However,the 15 saltmakesiteasiertoform arope-shapebaterythatdoesnot meltingpointofECisrelativelyhigh,39to40°C.,andthe havethetendencytoleakduringmanufacturingorduring viscositythereofisrelativelyhigh,sothattheconductivity bendingortwistingofthecablebatery.Furthersurprisingly, thereofislow,thusmakingECaloneunsuitedforuseasa wehaveobservedthatmostoftheelectrolytesbecome secondarybateryelectrolytetobeoperatedatrom tem non-flammablewhen thesaltconcentrationexceeds3.5M. peratureorlower.Thesecondsolventtobeusedinamixture 20 Somebecomesnon-flammableatasaltconcentrationgreater withECfunctionstomaketheviscosityofthesolvent than3.0Morjust>2.5M.Batteryscientistsandengineers mixturelowerthanthatofECalone,therebypromotingthe wouldexpectthathigherconcentrationmeanshighervis ionconductivityofthemixedsolvent.Furthermore,when cosityandlowerionmobilityand,hence,loweralkaliion thesecondsolventhavingadonornumberof18orles(the conductivity.Wehavefoundthatthistrendisgeneralytrue donornumberofethylenecarbonateis16.4)isemployed,25 ofthesaltconcentrationrangeof0.01M to2.0M.However, theaforementionedethylenecarbonatecanbeeasilyand quiteunexpectedly,thealkaliionconductivity(Li+,Na+, selectivelysolvatedwithlithiumion,sothatthereduction andK+ions)beginstoincreaseaftertheconcentrationis reactionofthesecondsolventwiththecarbonaceousmate- increasedtoexceedathresholdlevel(typicalybetween2.1 rialweldevelopedingraphitizationisassumedtobe and3.0M).Inotherwords,highersaltconcentrationslead supresed.Further,when thedonornumberofthesecond 30 toboth ahigher ion conductivity (asurprise)andnon solventiscontrolledtonotmorethan 18,theoxidative flammability(anothersurprise). decompositionpotentialtothelithium electrodecanbe Theionicliquidiscomposedofionsonly.Ionicliquids easilyincreasedto4Vormore,sothatitispossibleto arelowmeltingtemperaturesaltsthatareinamoltenor manufacturealithiumsecondarybateryofhighvoltage. liquidstatewhenaboveadesiredtemperature.Forinstance, Preferable second solvents are dimethyl carbonate35asaltisconsideredasanionicliquidifitsmeltingpointis (DMC),methylethylcarbonate(MEC),diethylcarbonate below10°C.Ifthemeltingtemperatureisequaltoorlower (DEC),ethylpropionate,methylpropionate,propylenecar thanromtemperature(25oC.),thesaltisreferedtoasa bonate (PC), gamma.-butyrolactone (.gamma.-BL), romtemperatureionicliquid(RTIL).TheILsaltsare acetonitrile(AN),ethylacetate(EA),propylformate(PF), characterizedbyweakinteractions,duetothecombination methylformate(MF),toluene,xyleneandmethylacetate40 ofalargecationandacharge-delocalizedanion.Thisresults (MA).Thesesecondsolventsmaybeemployedsinglyorin inalowtendencytocrystalizeduetoflexibility(anion)and acombinationoftwoormore.Moredesirably,thissecond asymmetry(cation). solvent should be selected from those having a donor A typical and well-known ionic liquid is formed by the numberof16.5orles.Theviscosityofthissecondsolvent combinationofa1-ethyl-3-methylimidazolium(EMI)cat should preferablybe 28 cps orles at25° C. 45 ion and an N,N-bis(trifluoromethane)sulphonamide (TFSI) Themixingratiooftheaforementionedethylenecarbon- anion.Thiscombinationgivesafluidwithanionicconduc ateinthemixedsolventshouldpreferablybe10to80%by tivitycomparabletomanyorganicelectrolytesolutionsand volume.Ifthemixingratiooftheethylenecarbonatefals alowdecompositionpropensityandlowvaporpresureup outsidethisrange,theconductivityofthesolventmaybe to-300-400°C.Thisimpliesagenerallylowvolatilityand loweredorthesolventtendstobemore easilydecomposed,50 non-flammability and,hence,amuch saferelectrolyte for therebydeterioratingthecharge/dischargeeficiency.More bateries. preferablemixingratiooftheethylenecarbonateis20to Ionicliquidsarebasicalycomposedoforganicionsthat 75%byvolume.Whenthemixingratioofethylenecarbon- comeinanesentialyunlimitednumberofstructuralvaria ateinanon-aqueoussolventisincreasedto20%byvolume tionsowingtothepreparationeaseofalargevarietyoftheir ormore,thesolvatingefectofethylenecarbonatetolithium 5components.Thus,variouskindsofsaltscanbeusedto ionswilbefacilitatedandthesolventdecomposition designtheionicliquidthathasthedesiredpropertiesfora inhibitingefectthereofcanbeimproved. givenaplication.Theseinclude,amongothers,imidazo Examplesofpreferedmixedsolventareacomposition lium,pyrolidiniumandquaternaryammoniumsaltsas comprisingECandMEC;comprisingEC,PCandMEC; cationsandbis(trifluoromethanesulphonyl)imide,bis(fluo comprisingEC,MEC andDEC;comprisingEC,MEC and 60 rosulphonyl)imide, and hexafluorophosphate as anions. DMC;andcomprisingEC,MEC,PCandDEC;withthe Basedontheircompositions,ionicliquidscomeindiferent volumeratioofMECbeingcontroledwithintherangeof30 clasesthatbasicalyincludeaprotic,proticandzwiterionic to80%.ByselectingthevolumeratioofMECfromthe types,eachonesuitableforaspecificaplication. range of 30 to 80%,more preferably 40 to 70%,the Common cations of rom temperature ionic liquids conductivity ofthesolventcanbe improved.With the65 (RTILs)include,butnotlimitedto,tetralkylamonium, purposeofsuppressingthedecompositionreactionofthe di-,tri-,andtetra-alkylimidazolium,alkylpyridinium, solvent,anelectrolytehavingcarbondioxidedisolved dialkyl-pyrolidinium,dialkylpiperidinium,tetralkylphos 23 alithiumsecondarybaterycanbeemployed.Anon-aque- thereinmaybeemployed,therebyefectivelyimproving oussolventmainlyconsistingofamixedsolventcomprising boththecapacityandcyclelifeofthebatery.Theelectro ethylenecarbonate(EC)andatleastonekindofnon- lyticsaltstobeincorporatedintoanon-aqueouselectrolyte aqueoussolventwhosemeltingpointislowerthanthatof maybeselectedfromalithiumsaltsuchaslithiumperchlo aforementioned ethylene carbonate and whose donor num - 5 rate (LiC102),lithium hexafluorophosphate (LiPF ),lithium beris18orles(hereinafterreferedtoasasecondsolvent) borofluoride(LiBF4),lithiumhexafluoroarsenide(LiAsF),PDF Image | FLEXIBLE AND SHAPE-CONFORMAL ROPE-SHAPE ALKALI METAL-SULFUR BATTERIES
PDF Search Title:
FLEXIBLE AND SHAPE-CONFORMAL ROPE-SHAPE ALKALI METAL-SULFUR BATTERIESOriginal File Name Searched:
US9905856.pdfDIY PDF Search: Google It | Yahoo | Bing
Sulfur Deposition on Carbon Nanofibers using Supercritical CO2 Sulfur Deposition on Carbon Nanofibers using Supercritical CO2. Gamma sulfur also known as mother of pearl sulfur and nacreous sulfur... More Info
CO2 Organic Rankine Cycle Experimenter Platform The supercritical CO2 phase change system is both a heat pump and organic rankine cycle which can be used for those purposes and as a supercritical extractor for advanced subcritical and supercritical extraction technology. Uses include producing nanoparticles, precious metal CO2 extraction, lithium battery recycling, and other applications... More Info
CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)