锂镍锰氧LNMO的制备

第十四届 摇篮杯 北京科技大学大学生课外学术科技作品赛 2015 材料合成化学PPT竞赛 SynthesisofLiNi0 5Mn1 5O4 Advantages highenergydensities obtainedeitherbyhighvoltageorhighcapacity Spinelstructure Positiveelectrodemateriaoflithiumbatteries LiNi0 5Mn1 5O4 Approachestosynthesize Solid statereactionsSol geltechnologyCoprecipitationsEmulsiondryingMoltensalttechnologySpraypyrolysis 5 Synthesisofprecursor Sinteringprocess Co precipitation 6 StoichiometricamountsofMn Li andNiacetatesweredissolvedinH2Oandstirredfor1h Oxalic acidsolutionwasthenaddeddropwiseunderstirring Theprecipitatesolutionwasstirredfor1hbeforebeingdriedat50 overnightwithconstantstirring Thedriedprecipitatewaspreheatedat500 for6handthengroundfor30min Thepreheatedpowderwaspressedintopellets 20mmdia andca 5mmthick andannealedat900 for24hinair Precipitate Drying Preheat Sintering PreparationProcess 7 Theadvantagesanddisadvantages Advantages EasytocontrolreactionprocessTheproductofparticlesgenerallysmallanduniform Goodelectrochemicalproperties Disadvantage NeedtoadjusttheproportionofLi Ni Mn Organiccoprecipitation SchematicIllustrationof8 HydroxyquinolineCoprecipitationRoute A B Ni Ac 2 6H2OMn Ac 2 4H2OLiAcambienttemperature water 8 hydroxyquinoline60 C ethanol solid liquiddispersion brownflocculentprecipitation stirfor2h evaporateat80 Cwithoutfiltration dryinginair 100 C preheatat470 Cfor5h darkpowerprecursor PreparationProcess Tocompare sampleswerepreparedusingsolid statemethod markedasSS andnormalcoprecipitationmethodwithKOHasprecipitant markedasHC aswell PreparationProcess SEMimagesof a samplesSS b samplesHC and c samplesQC Characterization morphology TheorganicprecipitatorcanbeeasilyremovedTheformationofLixNi1 xOimpuritiesandoxygendeficientcanbegreatlyrestrainedAvoidthedeviationintroducedbytheoxidationofsomeNi2 duringdrying Improvement Rapidheating HighUniformity Precisetemperaturecontrolling Microwavesintering Microwavetubefurnance PreparationProcess Characterization morphology Electricalperformance RequiringmuchshortertimeGrowingtooctahedralduringthepreferentialandrapidcrystalgrowthTuningtheMn3 contentofthespinelforenhancedelectrochemicalperformance Improvement Pulsedlaserdepositionisaphysicalvapordepositionprocess carriedoutinavacuumsystem thatsharessomeprocesscharacteristicscommonwithmolecularbeamepitaxyandsomewithsputterdeposition Pulsedlaserdepsition PLD 1 Pulsedlaserisfocusedontoatarget2 Laserpulsevaporizesorablatescreatingaplasmaplume3 Ablationplumeprovidesthematerialfluxforfilmgrowth PreparationProcess Electricalperformance SEMofLiNi0 5Mn1 5O4Film a and b initialdischargecurves c and d coulombicefficiencycurves Characterization morphology Improvement HighdepositionrateGoodcrystallinityEasytocontrolthicknessUniformityDirectstoichiometrytransferfromthetargettothefilm Advantages HighdepositionrateGoodcrystallinityEasytocontrolthicknessUniformityDirectstoichiometrytransferfromthetargettothefilm Electrospinning Characterization morphology Electricalperformance Electrochemicalcharacterization reversiblecapacity 102mA h g 1Operatingpotential 2 8VCapacityretention 86 after400cycles Advantages ShorteriondiffusiondistanceAccuraterstoichiometricratioofLiNi0 5Mn1 5O4Inhibittheaggregationofparticles References 1 D Liuetal Structure morphology andcathodeperformanceofLi1 x Ni0 5Mn1 5 O4preparedbycoprecipitationwithoxalicacidJournalofPowerSources195 2010 2918 2923 2 FengJ HuangZ GuoC etal AnorganiccoprecipitationroutetosynthesizehighvoltageLiNi0 5Mn1 5O4 J ACSappliedmaterials interfaces 2013 5 20 10227 10232 3 PoGao etc MicrowaverapidpreparationofLiNi0 5Mn1 5O4andtheimprovedhighrateperformanceforlithium ionbatteries J ElectrochimicaActa100 2013 125 132 4 CharlJ Jafta etc Microwave assistedsynthesisofhigh voltagenanostructuredLiNi0 5Mn1 5O4Spinel tuningtheMn3 contentandelectrochemicalperformance J ACSAppl Mater Interfaces2013 5 7592 7598 References 5 J Jian Y Y Zhu Q Su H Wang AnewapproachtoinvestigateLi2MnO3andLi Ni0 5Mn0 3Co0 2 O2mixedphasecathodematerials J J Mater Chem A 2014 2 2283 6 H Xia Y S Meng L Lu andG Ceder ElectrochemicalPropertiesofNonstoichiometricLiNi0 5Mn1 5O4 Thin FilmElectrodesPreparedbyPulsedLaserDeposition Electrochem Soc 2007 158 8 737 743 7 EijiHosono etc SynthesisofLiNi0 5Mn1 5O4and0 5Li2MnO3 0 5LiNi1 3Co1 3Mn1 3O2hollownanowiresbyelectrospinning J CrystEng