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1、关于碳纳米材料第一页，本课件共有28页Fourpartsv1.Introductionv2.Experimentv3.Resultsanddiscussionv4.Conclusions第二页，本课件共有28页Introductionvtransitionmetaloxideshaveattractedgreatattentionasanodematerialsforlithiumionbatteries,dueto1theirhightheoreticalcapacity2safety3lowcost4naturalabundance第三页，本课件共有28页vSomeobstacle1poo
2、rcyclingperformance(largevolumeexpansionduetothegenerationofLi2O)2poorelectronicconductivity(electrodematerialswithdesignednanostructurecanimproveit)第四页，本课件共有28页vMnOshowsrelativelylowelectromotiveforce电动势(emf)value(1.032Vvs.Li+/Li)andhighdensity(5.43gcm3).However,thiskindofmaterialhasseldombeenrepor
3、tedasananodematerialvnanocrystallineMnOthinfilm,andMnOpowderasanodehasshownlowoverpotential超电势andgoodcyclingperformance第五页，本课件共有28页vInthispaperThepreparedMnO/CcoreshellnanorodsmuchhigherspecificcapacitythanthatofMnOmicroparticlesandMnO2nanowiresasanodematerialoflithiumionbattery.返回第六页，本课件共有28页Experi
4、ment合成部分vMnO/CcoreshellnanorodsweresynthesizedbythereductionofcarbonprecursorcoatedMnO2nanowires.vTheMnO2nanowiresweresynthesizedbyatypicalhydrothermalreaction第七页，本课件共有28页Experiment表征vX-raydiffractionvFieldemissionscanningelectronmicroscopy(FESEM）vtransmissionelectronmicroscopy(TEM)vSAED第八页，本课件共有28页
5、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anddriedat120Covernightunder
6、vacuum第九页，本课件共有28页Experimentvelectrodeareais1cm2vloadingofactivematerialis1.01.2mgcm2velectrolyte:asolutionof1MLiPF6inethylenecarbonate碳酸亚乙酯(EC)anddimethylcarbonate碳酸二甲酯(DMC)withaweightratioof1:1第十页，本课件共有28页ExperimentvPurelithiumfoilwasusedascounterandreferenceelectrodevCyclicvoltammetry循环伏安法(CV)vCh
7、argedischargetestingwasperformedintherangeof0.013.0Vvspecificcapacity返回第十一页，本课件共有28页Resultsanddiscussionv1、MnO2nanowiresweresynthesizedbyhydrothermalreaction.Thecrystalstructureoftheas-preparedMnO2nanowireswasconfirmedbyXRD(Fig.1)vAllthediffractionpeakscanbeindexedtothebody-centeredtetragonal-MnO2ph
8、ase第十二页，本课件共有28页Resultsanddiscussionv2、MnO/CcoreshellnanorodswereobtainedthroughsinteringthecarbonprecursorcoatedMnO2nanowiresinflowingArcontaining5vol.%H2.AsshowninFig.1vthecrystalstructureofMnO/Ccoreshellnanorodscanbeindexedtotheface-centeredcubicphaseofMnOvlowintensitydiffractionpeakintherangeof2
9、030islikelyassociatedwiththepresenceofamorphouscarbon无定形碳(originatedfromthedecompositionofthecopolymersurfactant).第十三页，本课件共有28页Resultsanddiscussion第十四页，本课件共有28页ResultsanddiscussionFESEM:nanowire structure with diameters ranging from 2050 nm and There is no significant change in diameter第十五页，本课件共有28页
10、ResultsanddiscussionTEM第十六页，本课件共有28页Thenanorodsshowpolycrystallinefeatureandareagglomeratedintobundleswithalengthextendingtoafewhundrednanometers.ThefracturingofthenanowirestructureintonanorodsmaybecausedbythereductionfromMnO2toMnO.Anindividualnanorodconsistsofnanoparticleswithdiametersfrom20nmto30n
11、m.Resultsanddiscussion第十七页，本课件共有28页ResultsanddiscussionAllthediffractionringscanbeindexedtotheface-centeredcubicFm-3mcrystalstructure.第十八页，本课件共有28页ResultsanddiscussionHRTEM第十九页，本课件共有28页ResultsanddiscussionvIntheregionA:thesurfaceoftheMnOcrystal,andthelatticecanbeclearlyresolvedwithad-spacingof0.255n
12、mforthe(111)planes.vintheregionB:carbonlayer,whichpresentsnumerousblackspots,indicatingthatthesurfaceofthenanorodiscoveredwithathinlayerofamorphouscarbon.Ontheedgeofthenanorod,athincarbonlayerwithathicknessof12nmisclearlyvisible.第二十页，本课件共有28页Resultsanddiscussioncyclicvoltammetry(CV)第二十一页，本课件共有28页Res
13、ultsanddiscussion第二十二页，本课件共有28页Resultsanddiscussion第二十三页，本课件共有28页ResultsanddiscussionCyclingperformance第二十四页，本课件共有28页ResultsanddiscussionvThisnanorodelectrodeexhibitedhighercapacitythanthatofMnO2nanowireelectrodeafter40cycles.vThegoodelectrochemicalperformanceisaresultofthecombinedadvantagesofthenan
14、orodstructureandtheporouscarboncoatinglayer.第二十五页，本课件共有28页ResultsanddiscussionvNanosizematerialswithlargesurfaceareacanprovidemoreactivesitesforLi+intercalation/de-intercalationandshortenthediffusionlengthforlithiumionsinthesolidphase.vThenanoporouscarboncoatinglayerwithmesoporescanformamixedconduct
15、ing3DnetworkthatfacilitatesthemigrationofboththeLi+andthee,sothattheyreacheachsurfaceoftheMnOnanorods.返回第二十六页，本课件共有28页Conclusions1、UsingblockcopolymerF127asthecarbonsource,MnO/CcoreshellnanorodsweresuccessfullypreparedfromMnO2nanowiresbycalcinationinagasflowof5vol.%H2inAr.2、TheXRDpatternshowsthattheproducthasaface-centeredcubicphasestructure.FESEMandTEMimagesshowthatathincarbonlayerwascoatedonthesurfacesoftheMnOnanorods.第二十七页，本课件共有28页感感谢谢大大家家观观看看第二十八页，本课件共有28页