碳纳米材料精选PPT.ppt

关于碳纳米材料第1页，讲稿共28张，创作于星期二Fourpartsv1.Introductionv2.Experimentv3.Resultsanddiscussionv4.Conclusions第2页，讲稿共28张，创作于星期二Introductionvtransitionmetaloxideshaveattractedgreatattentionasanodematerialsforlithiumionbatteries,dueto1theirhightheoreticalcapacity2safety3lowcost4naturalabundance第3页，讲稿共28张，创作于星期二vSomeobstacle1poorcyclingperformance(largevolumeexpansionduetothegenerationofLi2O)2poorelectronicconductivity(electrodematerialswithdesignednanostructurecanimproveit)第4页，讲稿共28张，创作于星期二vMnOshowsrelativelylowelectromotiveforce电动势(emf)value(1.032Vvs.Li+/Li)andhighdensity(5.43gcm3).However,thiskindofmaterialhasseldombeenreportedasananodematerialvnanocrystallineMnOthinfilm,andMnOpowderasanodehasshownlowoverpotential超电势andgoodcyclingperformance第5页，讲稿共28张，创作于星期二vInthispaperThepreparedMnO/CcoreshellnanorodsmuchhigherspecificcapacitythanthatofMnOmicroparticlesandMnO2nanowiresasanodematerialoflithiumionbattery.返回第6页，讲稿共28张，创作于星期二Experiment合成部分vMnO/CcoreshellnanorodsweresynthesizedbythereductionofcarbonprecursorcoatedMnO2nanowires.vTheMnO2nanowiresweresynthesizedbyatypicalhydrothermalreaction第7页，讲稿共28张，创作于星期二Experiment表征vX-raydiffractionvFieldemissionscanningelectronmicroscopy(FESEM）vtransmissionelectronmicroscopy(TEM)vSAED第8页，讲稿共28张，创作于星期二Experiment电化学实验部分vperformingusing2032coin-typecellsassembledinanargon-filledgloveboxvslurry:activematerials(70wt%),acetyleneblack乙炔黑(20wt%),andpolyvinylidenefluoride聚偏二氟乙烯(PVDF10wt%)inN-methyl-2-pyrrolidone氮甲基二吡咯烷酮(NMP).vTheslurrywasspreadontotheCufoilwithadoctorblade刮墨刀片anddriedat120Covernightundervacuum第9页，讲稿共28张，创作于星期二Experimentvelectrodeareais1cm2vloadingofactivematerialis1.01.2mgcm2velectrolyte:asolutionof1MLiPF6inethylenecarbonate碳酸亚乙酯(EC)anddimethylcarbonate碳酸二甲酯(DMC)withaweightratioof1:1第10页，讲稿共28张，创作于星期二ExperimentvPurelithiumfoilwasusedascounterandreferenceelectrodevCyclicvoltammetry循环伏安法(CV)vChargedischargetestingwasperformedintherangeof0.013.0Vvspecificcapacity返回第11页，讲稿共28张，创作于星期二Resultsanddiscussionv1、MnO2nanowiresweresynthesizedbyhydrothermalreaction.Thecrystalstructureoftheas-preparedMnO2nanowireswasconfirmedbyXRD(Fig.1)vAllthediffractionpeakscanbeindexedtothebody-centeredtetragonal-MnO2phase第12页，讲稿共28张，创作于星期二Resultsanddiscussionv2、MnO/CcoreshellnanorodswereobtainedthroughsinteringthecarbonprecursorcoatedMnO2nanowiresinflowingArcontaining5vol.%H2.AsshowninFig.1vthecrystalstructureofMnO/Ccoreshellnanorodscanbeindexedtotheface-centeredcubicphaseofMnOvlowintensitydiffractionpeakintherangeof2030islikelyassociatedwiththepresenceofamorphouscarbon无定形碳(originatedfromthedecompositionofthecopolymersurfactant).第13页，讲稿共28张，创作于星期二Resultsanddiscussion第14页，讲稿共28张，创作于星期二ResultsanddiscussionFESEM:nanowire structure with diameters ranging from 2050 nm and There is no significant change in diameter第15页，讲稿共28张，创作于星期二ResultsanddiscussionTEM第16页，讲稿共28张，创作于星期二Thenanorodsshowpolycrystallinefeatureandareagglomeratedintobundleswithalengthextendingtoafewhundrednanometers.ThefracturingofthenanowirestructureintonanorodsmaybecausedbythereductionfromMnO2toMnO.Anindividualnanorodconsistsofnanoparticleswithdiametersfrom20nmto30nm.Resultsanddiscussion第17页，讲稿共28张，创作于星期二ResultsanddiscussionAllthediffractionringscanbeindexedtotheface-centeredcubicFm-3mcrystalstructure.第18页，讲稿共28张，创作于星期二ResultsanddiscussionHRTEM第19页，讲稿共28张，创作于星期二ResultsanddiscussionvIntheregionA:thesurfaceoftheMnOcrystal,andthelatticecanbeclearlyresolvedwithad-spacingof0.255nmforthe(111)planes.vintheregionB:carbonlayer,whichpresentsnumerousblackspots,indicatingthatthesurfaceofthenanorodiscoveredwithathinlayerofamorphouscarbon.Ontheedgeofthenanorod,athincarbonlayerwithathicknessof12nmisclearlyvisible.第20页，讲稿共28张，创作于星期二Resultsanddiscussioncyclicvoltammetry(CV)第21页，讲稿共28张，创作于星期二Resultsanddiscussion第22页，讲稿共28张，创作于星期二Resultsanddiscussion第23页，讲稿共28张，创作于星期二ResultsanddiscussionCyclingperformance第24页，讲稿共28张，创作于星期二ResultsanddiscussionvThisnanorodelectrodeexhibitedhighercapacitythanthatofMnO2nanowireelectrodeafter40cycles.vThegoodelectrochemicalperformanceisaresultofthecombinedadvantagesofthenanorodstructureandtheporouscarboncoatinglayer.第25页，讲稿共28张，创作于星期二ResultsanddiscussionvNanosizematerialswithlargesurfaceareacanprovidemoreactivesitesforLi+intercalation/de-intercalationandshortenthediffusionlengthforlithiumionsinthesolidphase.vThenanoporouscarboncoatinglayerwithmesoporescanformamixedconducting3DnetworkthatfacilitatesthemigrationofboththeLi+andthee,sothattheyreacheachsurfaceoftheMnOnanorods.返回第26页，讲稿共28张，创作于星期二Conclusions1、UsingblockcopolymerF127asthecarbonsource,MnO/CcoreshellnanorodsweresuccessfullypreparedfromMnO2nanowiresbycalcinationinagasflowof5vol.%H2inAr.2、TheXRDpatternshowsthattheproducthasaface-centeredcubicphasestructure.FESEMandTEMimagesshowthatathincarbonlayerwascoatedonthesurfacesoftheMnOnanorods.第27页，讲稿共28张，创作于星期二感谢大家观看第28页，讲稿共28张，创作于星期二