28445.過渡金屬氧化物基復(fù)合納米材料的設(shè)計制備及儲鋰性能研究

1、學(xué)位論文獨創(chuàng)性聲明本人鄭重聲明：所提交的學(xué)位論文是本人在導(dǎo)師指導(dǎo)下進行的研究工作和取得的研究成果。本論文中除引文外，所有實驗、數(shù)據(jù)和有關(guān)材料均是真實的。本論文中除引文和致謝的內(nèi)容外，不包含其他人或其它機構(gòu)已經(jīng)發(fā)表或撰寫過的研究成果。其他同志對本研究所做的貢獻均己在論文中作了聲明并表示了謝意。學(xué)位敝儲簽名瀟嗽日期：塒餅學(xué)位論文使用授權(quán)聲明研究生在校攻讀學(xué)位期間論文工作的知識產(chǎn)權(quán)單位屬南京師范大學(xué)。學(xué)校有權(quán)保存本學(xué)位論文的電子和紙質(zhì)文檔，可

2、以借閱或上網(wǎng)公布本學(xué)位論文的部分或全部內(nèi)容，可以采用影印、復(fù)印等手段保存、匯編本學(xué)位論文。學(xué)?？梢韵驀矣嘘P(guān)機關(guān)或機構(gòu)送交論文的電子和紙質(zhì)文檔，允許論文被查閱和借閱。(保密論文在解密后遵守此規(guī)定)保密論文注釋：本學(xué)位論文屬于保密論文，密級：——保密期限為——年。學(xué)位論文作者簽名：翔沁似指導(dǎo)刻讎：用繃13期：汕叩弋押日期：加I斗s、乙。AbstractAbstractTransitionmetaloxides(TMOs)havebeenr

3、egardedasanidealanodiccandidateteplacecommercialgraphiticmaterialsforfithiumionbatteries(LIBs)owingtoitshightheoreticalcapacityButTMOsstillsufferfromlowintrinsicelectricalconductivityandpoorstructuralstabilityduringlithi

4、uminsertion／extractionwhichleadtolowratecapabilityandpoorcyclingstabilityandthushinderitspracticalapplicationinadvancedLIBsThepreparationofspecialmorphologicaltransitionmetaloxidenanomaterialsandhybridnanostructuredmater

5、ialsisthemainwaytosolvetheseproblemsSpecialmorphologyofnanomaterialstendstohavelargerspecificsurfacearea，whichcanhaveagoodcontactwiththeelectrolyteandshortenthetransmissiondistanceofelectronic／ionhybridnanostructuredmate

6、rialscanimprovetheelectricalconductivityoftheelectrodematerialacceleratetheelectrontransferimprovetherateperformance，Canalsoeasethevolumeexpansionoftheelectrodematerialduringlithiuminsertion／extractionavoidthematerialagg

7、lomerationandpulverizationimprovethecycleperformance，andultimatelymeettheneedsofthepowerbatteryHereinwepreparevariouscompositeelectrodematerialsbyusingTFe203，CoO，NiOasactivematerialsandcompositewithmultiplewallcarbonnano

8、tube(MWCNT)，Ndopedcarbonandpolypyrrole(PPy)，respectivelyandfinallyusedinanodematerialsofLIBsThehybridnanostructuredmaterialsexhibithigherspecialcapacitybettercycleandrateperformancecomparedtoasinglecomponentofactivemater

9、ialsInthispaperthemaininnovationpointsareasfollows：(1)Wehaveanchoredmaghemite(yFe203)nanocrystalscompactlyanduniformlyonmultiwalledcarbonnanotubes(MWCNT)throughafacilelayer—by—layerassemblyandsubsequentannealingapproachC

10、omparewithyFe203nanocrystals，theMWCNTyFe203hybridnanostructuredmaterialsexhibitwellelectrochemicalperformance，forexample，atacurrentdensityof100mAg一，theMWCNTy—Fe203nanohybridisabletodeliverahighreversiblecapacityof9393mAh

11、g。1atthe50thcycle，andevenatacurrentdensityof1Ag～，theMWCNT丫Fe203nanohybridisabletodeliverahighreversiblecapacityof6220mAhg～(2)WehavedesignedandsynthesizedanoveltypeofnitrogendopedcarbonsupportedCoOnanohybrids，ienitrogen—d