PDF Publication Title:
Text from PDF Page: 017
11 cathodeactivematerial-coatedgrapheneshets,alongwith anoptionalbinderand/oranoptionalcarbon/graphitemate rial, to directly form a cathode electrode without going throughtheintermediatestepofformingsecondaryparticles. staticsprayingdeviceisusedtopropelanddepositgraphene materialshetsontothesubstratesurfacesothatmultiple15 graphenematerialshetsareoverlappedtoformacohered filmorshet,fromapproximately0.5nmtoseveralmicron thick(preferablyfrom1nmto20nm). 12 nm).ThisSupportingfilmpreferablyhasathicknessbetween 0.4nmand20nm,morepreferablybetween0.4nmand5nm. Ananographeneplatelet(NGP)orgrapheneshetiscom posedofonebasalplane(grapheneplane)ormultiplebasal planesstackedtogetherinthethicknessdirection.Ina thick,morepreferablylesthan100nm,furtherpreferably30 lesthan50nm,andmostpreferablylesthan20nm. theirpreparation,resultingingraphiteoxide(GO)or grapheneoxide.Hence,inthepresentcontext,graphenepref erablyorprimarilyreferstothosegrapheneshetscontaining noorlowoxygencontent;but,theycanincludeGOofvarious oxygencontents.Further,graphenemaybefluorinatedtoa controledextenttoobtaingraphenefluoride. US9,203,084B2 Instep(a),thecontinuousshetofagraphenematerial(the continuousfilm)maybeproducedbychemicalvapordepo sition(CVD)ofgrapheneontoasolidsubstrate.However,the CVDisanexpensiveproces.Alternativelyandpreferably,as ilustratedinFIG.1,thiscontinuousfilmmaybeproducedby preparingaSuspensionofgraphenematerialshets(e.g.10 grapheneoxideshets)inaliquidmedium(e.g.water)and sprayingtheSuspensionontoaSolidSubstratesurfacetoform 100nm(multi-layer).Forthepresentelectrodeuse,thepre agraphenefilm.Preferably,anultrasonicsprayingorelectro Thisgraphenefilm,withorwithouttheSupportingSub strate,isthenintroducedintoadepositionZone(e.g.avacuum chamberoraCVDchamber)whereinstreamsofvaporor atomsofacathodeactivematerialaredepositedontoone Surfaceofthegraphenefilmtoformacoatedfilm(e.g. S-coatedgraphenefilm).Thisdepositionmaybeaccom plishedthroughphysicalvapordeposition(PVD),Sputering,25 laser-asisteddeposition,chemicalvapordeposition,includ ingplasma-enhancedCVDandhot-wireCVD.atomiclayer deposition,anddepositionfromsolution.Thethicknessofthe anodeactivematerialcoatingispreferablylesthan500nm Grapheneshetsmaybeoxidizedtovariousextentsduring AgainreferingtoFIG.1,thecathodematerial-coated graphenefilmisthenSubjectedtomechanicalbreakageto producepiecesofcathodeactivematerial-coatedgraphene shetswithalateraldimensionpreferablyintherangeof0.335 umto10uM,butfurtherpreferablyfrom0.5umto3um. TheNGPsmaybeobtainedfromexfoliationandplatelet ThesesizerangesareparticularlySuitableforcombining theseprimaryparticles(cathodeactivematerial-coated grapheneshets)intosecondaryparticlesorparticulateswith adiameterintherangeof1umto10um,preferablylesthan40 5um.Thesesecondaryparticleswithpropersizesareame nabletothefabricationofcathodemateriallayersonacath Inapreferedversionoftheproces,thecontinuousfilmof odecurentcolectorusingconventionalslurycoatingpro ceses.Thesluriescontainingthesesecondaryparticlesare foundtohaveverydesirableviscosityandotherflowcharac45 teristics.Theyflowverywellonthesurfaceofacathode curentcolector(e.g.Alfoil).Theresultingelectrodethick nesscanbefrom50umto500umorthicker,butmost preferablyfrom100umto250um. agraphenematerialmaybeproducedby(a)sprayinga grapheneSuspensionontoasolidSubstrate,whereinthe grapheneSuspensioncontainsdiscreteshetsorplateletsofa graphenematerialdispersedinaliquidmedium,and(b) removingtheliquidmedium.Alternatively,thecontinuous shetofagraphenematerialmaybeproducedbychemical vapordepositionofagraphenematerialontoasolidSubstrate. AsilustratedinthetopportionofFIG.1,theuseofa 50 graphenefilmpreparedbydepositionfromagrapheneSus pensionispreferedoveraCVDgraphenefilmbecauseofthe needtobreakthefilm,afterbeingcoatedwithacathodeactive material,intoSmallpiecesofcoatedgrapheneshets.The continuousgraphenefilmmadefromoverlappedgraphene55 shetscanbereadilybrokenalongtheoriginalgraphenesheet boundaries.Theresultingcoatedgrapheneshetsarecompa rableinsizestotheoriginalgraphenematerialshets.The Intheproces,step(c)ofmechanicalbreakingcanbe Suspension-derivedgraphenefilmismuchweakerthanthe CVDgraphenefilm.However,wehaveturnedthisweakness60 intoanadvantageousfeaturefortheproductionofcoated grapheneshetsofdesiredsizes. Thepresentinventionprovidesananographene-enhanced particulate(secondaryparticle)foruseasalithium-ionbat teryelectrodematerial.TheSupportinggraphenefilmispref65 erablymadefromsingle-layergrapheneorfew-layer graphene(upto10grapheneplanes,orapproximately<4-5 conductedusingairjetmiling,impactmiling,grinding. mechanicalshearing,ultrasonication,oracombination thereof. FIG.2showsanexampleofgraphene-enhancedparticu latescomprisinggrapheneshetsinandaroundtheparticu late.Grapheneshetsembraceandprotecttheprimarypar ticles(S-coatedgrapheneshets)toformsecondaryparticles (particulates)thatareeasiertohandleinarealanodeproduc tionenvironment.Theembracinggrapheneshetsalsopre grapheneplane,carbonatomsoccupya2-Dhexagonallatice inwhichcarbonatomsarebondedtogetherthroughstrong in-planecovalentbonds.Inthec-axisorthicknessdirection, thesegrapheneplanesmaybeweaklybondedtogether throughvanderWaalsforces.AnNGPcanhaveaplatelet thicknessfromlesthan0.34nm(single-layergraphene)to feredthicknesis<10nmandmostpreferably<3nmor10 layers).Thepresentlyinventedanodeactivematerial-coated shetsandtheresultinggraphene-enhancedsecondarypar ticleorparticulatepreferablycontainsmostlysingle-layer graphene,butcouldmakeuseofsomefew-layergraphene (lesthan10layers).Thegrapheneshetmaycontainasmall amount(typicaly<25%byweight)ofnon-carbonelements, Suchashydrogen,boron,fluorine(orotherhalogen),nitro gen,andoxygen,whichareattachedtoanedgeorSurfaceof thegrapheneplane.Graphenewasrecentlydiscoveredto exhibitthehighestthermalconductivityofalexistingmate rials.Inaditiontotheelectricalconductivity,thishighther malconductivityisclearlyanadvantageouspropertythat couldnotbeachievedbyanyothertypeofconductiveaddi tives.Graphenealsoexhibitsthehighestintrinsicstrength amongalmaterialseverreported. separationofanaturalgraphite,syntheticgraphite,highly orientedpyrolyticgraphite,graphitefiber,carbonfiber,car bonnano-fiber,graphiticnano-fiber,sphericalgraphiteor graphiteglobule,meso-phasemicro-bead,meso-phasepitch, graphiticcoke,orgraphitizedpolymericcarbon. Theshetofacathodeactivematerial-coatedgraphene filmpreferablyhasacathodeactivematerialcoatingthick nesslesthan500nm,morepreferablylesthan100nm, furtherpreferablylesthan50nm,mostpreferablylesthan 20nm.Thecoatedshetmaybeproducedthroughchemical vapordeposition,physicalvapordeposition,Sputering,or laser-asistedthin-filmdepositionofananodeactivematerial ontoashetofagraphenematerial.PDF Image | CATHODE ACTIVE MATERIAL-COATED DISCRETE GRAPHENE SHEETS FOR LITHIUM
PDF Search Title:
CATHODE ACTIVE MATERIAL-COATED DISCRETE GRAPHENE SHEETS FOR LITHIUMOriginal File Name Searched:
US9203084.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)