【优秀硕士博士论文】富锂层状材料li-ni-mn-o的合成和性能改进研(01)

20170625STUDYONTHESYNTHESISANDELECTROCHEMICALPERFORMANCESOFLIRICHCATHODEMATERIALFORLITHIUMIONBATTERIES20170625CONTENTS一、研究背景二、研究目的三、研究内容四、研究进展4LAYEREDSPINELSTRUCTURES1INTRODUCTION2HOMOGENEOUSCOPRECIPITATION3TOBECOATEDBYVO2201706251INTRODUCTION1INTRODUCTIONCOMPAREDTOOTHERRECHARGEABLESYSTEMS,LITHIUMIONBATTERIESOFFERHIGHERENERGYDENSITY,POWERINGWIDERANGEOFPORTABLEELECTRONICDEVICES201706252LIMN2O4LOWCAPACITY,POORCYCLELIFEANDMNDISSOLUTION3LIFEPO4POORELECTRONICCONDUCTIVITY,LOWRATEOFLITRANSPORT,ANDLOWENERGYDENSITY1LICOO2COPOLLUTION,HIGHCOSTANDSAFEPROBLEMITISNECESSARYTODEVELOPHIGHCAPACITYMATERIALMORETHAN200MAHG1201706251INTRODUCTIONRESEARCHAREAHIGHCAPACITYLIRICHMATERIALLIMO2OLIMLI2MNO3LILIXM1XO2ORXLI2MNO31XLIMO2（MNI,CO,MNORNI05MN05；LIMO2NAFEO2,LAYEREDMATERIAL,R3M；LI2MNO3NAFEO2LIKEPHASE,LAYEREDMATERIAL,C2/MTHACKERAYETALSAIDTHESTRUCTURESARECOMPRISEDOFNANOMETERREGIONSWITHLI2MNO3ANDLIMO2LIKEFEATURES,ACCORDINGTOTHERESULTSOFXRD,XAS,HRTEMANDNMRMMTHACKERAY,ETALCHEMMATER2008,20,6095201706251INTRODUCTIONSTRUCTURELI12NI02MN06O2ISCOMPOSEDOFASOLIDSOLUTIONWITHC2/MMONOCLINICSYMMETRYANDMULTIPLEPLANARDEFECTS,WITHACOMBINATIONOFXRD,ED,STEM,STEMCOMPUTERSIMULATIONS,ANDDSTEMKAFERREIRA,ETALCHEMMATER2011,23,3615201706251INTRODUCTIONSTRUCTUREMMTHACKERAY,ETALJMATERCHEM2007,17,3113ABCD201706251INTRODUCTIONINITIALCYCLE富锂材料首圈充放电行为示意图XLI2MNO31XLIMO2XLI2MNO31XMO21XLIXLIMNO21XLIMO2XMNO21XMO2XLI2OABCDMMTHACKERAY,ETALJMATERCHEM2005,15,2257INCREASINGTHEDISCHARGECAPACITYMAINTAININGSTRUCTURALSTABILITYENSURINGFASTREACTIONKINETICS201706251INTRODUCTIONLI2MNO31LARGEIRREVERSIBLECAPACITYLOSSINTHEINITIALCYCLE2CAPACITYFADEAFTERLONGTIMECYCLES3POORRATEPERFORMANCEIMPROVEMENTDISADVANTAGE1DOPINGWITHOTHERIONSCO3,AL3,CR32PREPARINGNANOMATERIALNANOLINE,NANOPLATE3SURFACEMODIFICATION（COATING,ACIDTREATED201706251INTRODUCTIONAL2O3COATINGSTMYUNG,ETALCHEMMATER2005,17,3695STMYUNG,ETALJPHYSCHEMC,2007,111104061YJKANG,ETAL,ELECTROCHACTA,2005,50244784KSTAN,ETALJPOWERSOURCE,2005,1411129JMZHENG,ETAL,LIJ,SOLIDSTATEIONICS,2008HEAL2O3COATEDMATERIALHADGREATLYIMPROVEDCYCLABILITYWITHHIGHRECHARGEABLECAPACITYDUETOTHEIMPACTOFTHECOATINGLAYERINPROTECTINGTHESURFACEAGAINSTHFATTACKOTHERCOATINGMATERIALNB2O5、TA2O5、ZRO2、TIO2、ZNO、ALOH3、ALPO4、LINIPO4THECOATEDMATERIALDIDNOTOPERATEWITH100COULOMBICEFFICIENCYONTHEFIRSTCYCLE1INTRODUCTIONTHEHNO3TREATEDMATERIALOPERATEWITH100COULOMBICEFFICIENCYONTHEINITIALCYCLEBUTTHECYCLEPERFORMANCEWASINFERIORTOUNTREATEDELECTRODEASTHEPRECONDITIONINGREACTIONCHANGESTHESTRUCTUREASARESULTOFPOSSIBLEH/LIEXCHANGEHNO3TREATEDSKKANG,ETALJELECTROCHEMSOC2006,153,A1186201706251INTRODUCTION1TOBECOATEDBYVO2ONTHESURFACEVIAHYDROTHERMALREDUCTIONLI2MNO3LI2OCHARGEMNO2LIDISCHARGELIMNO2LOSEONEOANDONELIVO2OCHARGEV2O5LIDISCHARGELIXV3O8ADDONEOANDONELI201706251INTRODUCTIONLILIRICHCOATINGLAYERLIOXIDESTATECHARGEDISCHARGE2TOYIELDINTEGRATEDLAYEREDSPINELSTRUCTURESLICHARGELIDISCHARGELAYERSPINELLI2MNO3LI2OCHARGEMNO2LIDISCHARGELIMNO2LIMN2O4LICHARGEMN2O42LIDISCHARGELI2MN2O4LOSEONELIADDONELI201706251INTRODUCTION201706252HOMOGENEOUSCOPRECIPITATIONMETHOD20170625PREPARATIONMETHODSBALLMILLINGSOLGELOTHERMETHODSCOPRECIPITATIONHYDROTHERMALMETHOD2HOMOGENEOUSCOPRECIPITATIONMETHODHYDROXIDECARBONATE201706252HOMOGENEOUSCOPRECIPITATIONMETHODMNSO4,NINO326H2O,CONH22,H2OSOLUTIONAUTOCLAVECARBONATECALCINATIONCOINCELLLI2CO3THEDECOMPOSITIONOFUREARELEASESPRECIPITATINGANIONSMAINLYOHANDCO32SLOWLYANDHOMOGENEOUSLYINTOTHEREACTIONSYSTEMSATELEVATEDTEMPERATURE,ANDTHUSRESULTSINTHEHOMOGENEOUSPRECIPITATIONOFTHEPRECURSORPARTICLESEVENWITHOUTSTIRRINGA05H,B1H,C2H,D4H,E6H,F12HCONCENTRATIONSOFNIAFTER2H,THENICO3PEAKSBECAMEMORECLEARLYAFTER6H,THECONCENTRATIONSOFNIWHENTHETIMEWASUPTO1HOUR,SPHERICALPARTICLESAPPEAREDAFTER2H,THECOLLECTEDPARTICLES,COMPOSEDOFNANOSIZEDPRIMARYPARTICLES,AREALLWITHSPHERICALMORPHOLOGY,ANDTHEAVERAGEPARTICLESIZEISABOUT2672M2HOMOGENEOUSCOPRECIPITATIONMETHOD201706252HOMOGENEOUSCOPRECIPITATIONMETHODREACTIONTIMEAASEMOFTHEINTERCROSSSECTIONANDBLINESCANNINGRESULTSTHECONTENTSOFNIWHENTHEMOLARRATIOOFUREATONIANDMNWAS0510,NIOOHANDMNOH2WEREOBSERVEDTHEOPTIMIZEDMOLARRATIOOOFUREAANDTRANSITMETALWEREOBTAINEDAT2010XRDPATTERNSOFLINI02LI02MN06O2SEMIMAGESOFTHEPOWDERS20170625ABDLINESCANRESULTSSEMIMAGEOFTHEINTERCROSSSECTION2HOMOGENEOUSCOPRECIPITATIONMETHODSOMEWEAKPEAKSBETWEEN20AND25OF2CHARACTERIZESLI2MNO3THEMORPHOLOGYOFTHESECONDARYPARTICLESMAINTAINSSPHERICALAFTERTHECALCINATION,THENIRICHLAYERONTHEPARTICLESURFACEBECAMELESSOBVIOUSFIRSTANDSECONDCHARGEDISCHARGEPROFILES201706252HOMOGENEOUSCOPRECIPITATIONMETHODBELOW45VTHEOXIDATIONOFNI2TONI4ABOVE45VTHEELECTROCHEMICALREMOVALOFLI2OFROMTHESTRUCTURETHE1STCHARGETHE1STDISCHARGEABOVE35VTHEREDUCTIONOFNI4TONI2BELOW35VTHEREDUCTIONOFMN4TOMN2DERIVEDFROMLI2MNO3201706252HOMOGENEOUSCOPRECIPITATIONMETHODADIFFERENTTEMPERATURESBATTHELOWUREACONCENTRATION,THECO32RELEASEDBYUREAISNOTENOUGHATHIGHUREACONCENTRATION,MORENINH3N2ISLEFTINSOLUTION201706252HOMOGENEOUSCOPRECIPITATIONMETHODCONCLUSIONCOMBINEDWITHXRD,SEM,ANDPARTICLESIZEANALYSIS,THEOPTIMIZEDCONDITIONSTOATTAINDESIREDSTOICHIOMETRICNI025MN075CO3WERECONFIRMEDAS200OC,6HOURS,ANDTHEMOLARRATIOOFUREATOTRANSITIONMETALSNIANDMNOF2010THEREACTIONSTARTEDWITHTHEFORMATIONOFSEEDSWITHNODEFINEDSHAPE,CONTINUEDWITHTHEGROWINGOFTHESESMALLPARTICLES,ANDENDEDWITHTHEPRODUCTIONOFSPHERICAL,HOMOGENEOUSPARTICLESAVERAGEPARTICLESIZEWAS2667MWITHTHETRANSITIONMETALRATIOCLOSETOTHATOFTHEREACTANTSTHESAMPLEHADADISCHARGECAPACITYOFABOUT237MAHG1ATTHEINITIAL,EXHIBITINGGOODCYCLINGPERFORMANCE201706253TOBECOATEDBYVO2ONTHESURFACEVIAHYDROTHERMALREDUCTION201706253TOBECOATEDBYVO2VIAHYDROTHERMALREDUCTIONMASSSPECTROMETRYBRUCEETALSAIDEVOLUTIONOFOXYGENWASOBSERVEDABOVE45VKOMABAETALBELIEVETHATTHERELEASEDOXYGENISELECTROCHEMICALREDUCEDTOFORMLI2CO3,WHICHISHARMFULTOTHECYCLEABILITYBRUCEETAL,JAMCHEMSOC128,2006,8697KOMABAETAL,JAMCHEMSOC133,2011,4404ITISNECESSARYTOABSORBTHERELEASEDOXYGENLI2MNO3LI2OCHARGEMNO2LIDISCHARGELIMNO2LOSEONEOANDONELIVO2OCHARGEV2O5LIDISCHARGELIXV3O8ADDONEOANDONELI20170625LILIRICHCOATINGLAYERLIOXIDESTATECHARGEDISCHARGE3TOBECOATEDBYVO2VIAHYDROTHERMALREDUCTION3TOBECOATEDBYVO2VIAHYDROTHERMALREDUCTIONSOMEWEAKPEAKSBETWEEN20AND25OF2CHARACTERIZESLI2MNO3THEXRDPATTERNSOFVO2COATEDSAMPLESDISPLAYASLIGHTBROADENINGOFTHEMAJORPEAKS,BUTTHEREISESSENTIALLYNOCHANGEINTHEPOSITIONSOFPEAKSNOOBVIOUSPEAKSCORRESPONDINGTOVO2AREFOUNDINTHEXRDPATTERNSVO2WITHHIGHPURITYCOULDBEOBTAINEDFROMNH4VO3VIAHYDROTHERMAOLREDUCTIONWHEREPVPSERVEDASAREDUCINGAGENTSYNTHESISMETHODNAMEV15V10V5V03TOBECOATEDBYVO2VIAHYDROTHERMALREDUCTIONTHEOVERALLPARTICLESHAPEANDSIZEWERENOTESSENTIALLYAFFECTEDBYTHEVO2COATINGTHECONTENTSOFV,NIVO2WASNOTONLYCOATEDONTHESPHERES,BUTALSOTHEPRIMARYPARTICLESINSIDETHECRYSTALLINEMATERIALABACTIVEMATERIALCOATINGLAYERACTIVEMATERIALCOATINGLAYERDC3TOBECOATEDBYVO2VIAHYDROTHERMALREDUCTIONTHEVO2COATEDMATERIALCLEARLYSHOWEDAROUGHCOATINGLAYERWITHDIFFERENTTHICKNESSTHESURFACEVO2ISNOTINWELLCRYSTALLINESTATETHEENERGYDISPERSIVEXRAYEDXSPECTRACONFIRMSTHECOEXISTENCEOFV,MNANDNIELEMENTS201706253TOBECOATEDBYVO2VIAHYDROTHERMALREDUCTIONWITHINCREASINGSPUTTERINGDEPTH,THERELATIVECONCENTRATIONOFMN2PBECAMEHIGHERONTHEOTHERHAND,THATOFTHEV2PWASGETTINGLOWERONARIONETCHING3TOBECOATEDBYVO2VIAHYDROTHERMALREDUCTIONTHEBARESAMPLEEXHIBITSALARGEIRREVERSIBLECAPACITYLOSSOF122MAHG1INTHEINITIALCYCLETHEVO2COATEDSAMPLESDELIVEREDMUCHHIGHERCOULOMBICEFFICIENCYFORTHEINITIALCYCLETWONEWPEAKSONEISOBSERVEDBETWEEN42VAND45V,ANDTHEOTHERISBELOW28VTHELIEXTRACTIONREACTIONINTHEFIRSTCYCLEDIFFEREDFROMTHATINSUBSEQUENTCYCLES201706253TOBECOATEDBYVO2VIAHYDROTHERMALREDUCTIONABEFORECHARGED,BCHARGEDTO48V,ANDCDISCHARGEDTO20V3TOBECOATEDBYVO2VIAHYDROTHERMALREDUCTIONTHECAPACITYFADEINCREASESWITHINCREASINGCOATINGCONCENTRATIONTHISISDUETOTHEFASTERCAPACITYFADEOFLIV3O8LIKEPHASE20170625CONCLUSIONWEPROPOSEDANOVELSTRATEGYTOELIMINATETHEIRREVERSIBLECAPACITYLOSSBYCOATINGWITHAREDOXCOUPLEMATERIALBYCOMBINGTHEELECTROCHEMICALRESULTS,WECONCLUDETHEREACTIONMECHANISMOFTHEVO2COATEDBUTWEDONTUNDERSTANDWHYTHEINITIALCHARGECAPACITYWASONLY240MAHG1FORTHE10ATVO2COATEDMATERIAL,WHILETHEREWAS343MAHG1FORTHEBAREONE3TOBECOATEDBYVO2VIAHYDROTHERMALREDUCTION201706254TOYIELDINTEGRATEDLAYEREDSPINELSTRUCTURESLICHARGELIDISCHARGELAYERSPINELLI2MNO3LI2OCHARGEMNO2LIDISCHARGELIMNO2LIMN2O4LICHARGEMN2O42LIDISCHARGELI2MN2O4LOSEONELIADDONELI201706254TOYIELDINTEGRATEDLAYEREDSPINELSTRUCTURESICPRESULTSXRDSEM4TOYIELDINTEGRATEDLAYEREDSPINELSTRUCTURESSAMPLELI/MNMOLERATIOANALYZEDFORMULACOULOMBICEFFICIENCYFORTHE1STCYCLENAMEA1436LI118NI0250MN0572O27021LI118900B1146LI103NI0277MN0622O29395LI103900C1143LI105NI0277MN0642O29989LI105800PERHAPSFOURPHASESINSAMPLELI103900ANDLI10580020170625OLIMLIMN2O4LI2MNO3LINI05MN05O2OLIMNNILINI05MN15O44TOYIELDINTEGRATEDLAYEREDSPINELSTRUCTURES201706254TOYIELDINTEGRATEDLAYEREDSPINELSTRUCTURESTEMANDXPSSPECTRAOFTHEMN2PREGIONSOFALI118900,BLI103900ANDCLI105800SMALLSHOULDERSAPPEARINTHESIGNALSSAMPLEBANDC,INDICATETHEEXISTENCEOFMN3HRTEMIMAGESHOWSTHECOMPOSITECHARACTEROFTHEPOWDERSWITHNANODOMAINSOFTHELAYEREDSPINELCOMPONENTSCHARGE45VPEAKTHEELECTROCHEMICALREMOVALOFLI2OFROMLI2MNO3FORSAMPLELI103900ANDCLI105800,PEAKSCPEAKSHITHEREVERSIBLETRANSITIONOFLIM2O4TOLI2M2O4THEREMIGHTBESOMESTRUCTURETRANSFORMATION4TOYIELDINTEGRATEDLAYEREDSPINELSTRUCTURESDQ/DVC