铝-空气电池阴极催化剂的制备及表征

硕士学位论文铝-空气电池阴极催化剂的制备及表征PREPARATIONANDCHARACTERIZATIONOFCATHODEELECTROCATALYSTFORALUMINUM-AIRBATTERY刘臣娟哈尔滨工业大学2013年7月国内图书分类号：O611.5学校代码：10213国际图书分类号：661.8密级：公开理学硕士学位论文铝-空气电池阴极催化剂的制备及表征硕士研究生：刘臣娟导师：周育红高级工程师申请学位：理学硕士学科：无机化学所在单位：理学院化学系答辩日期：2013年7月授予学位单位：哈尔滨工业大学ClassifiedIndex:O611.5U.D.C:661.8DissertationfortheMasterDegreeinSciencePREPARATIONANDCHARACTERIZATIONOFCATHODEELECTROCATALYSTFORALUMINUM-AIRBATTERYCandidate：LiuChenjuanSupervisor：ZhouYuhongSeniorEngineerAcademicDegreeAppliedfor：MasterofScienceSpeciality：InorganicChemicalAffiliation：DepartmentofChemistryDateofDefence：July,2013Degree-Conferring-Institution：HarbinInstituteofTechnology哈尔滨工业大学理学硕士学位论文I摘要铝空气电池的结构是：阳极铝金属|电解质|阴极氧气，具有较高的理论开路电压2.73V和优异的比能量(金属铝的比能量为8.1kWh/kg；电池的比能量为2.8kWh/kg)，近年来引起了全世界的关注,是一种具有发展潜力的新型电源体系。而催化剂的性质对铝-空气电池的放电性能有很大的影响，石墨烯作为一种新型的铝-空气电池催化剂，因其具有良好的物理、化学和机械性能使其在催化载体等方面有着潜在的应用前景。本论文尝试将石墨烯作为催化剂及载体应用于铝-空气电池空气阴极。主要用热膨胀法制备了石墨烯，用微波辅助乙二醇法制备石墨烯基铂-钴合金催化剂(Pt-Co/rGO)，并将其应用于铝空气电池阴极。通过X-射线衍射、红外光谱、扫描电镜、拉曼光谱、透射电镜等测试手段对催化剂粉末进行表征，观察其形貌。利用循环伏安、线性扫描、恒流放电对空气电极进行测试。实验结果表明增加预处理过程，增长冰浴时间能得到氧化性较好的氧化石墨，使用PANI修饰制备的石墨烯具有较大的比表面积，还原效果好。在石墨烯上负载Pt-Co合金，改变金属Pt与Co质量比，发现当质量比为1:2时，所制备的催化剂具有较好的氧还原活性。分别将XC-72和MWCNT与石墨烯复合做催化剂载体，发现其活性远高于单独使用XC-72、MWCNT和石墨烯基催化剂的活性。当GO与XC-72质量之比为2:1时，得到的空气电池，在相同放电条件下具有更高的放电平台。在10mA、20mA、30mA、40mA放电条件下分别可以达到1.31V、1.0V、0.54V、0.48V。当GO与MWCNT质量之比为2:1时，得到的空气电池，在相同放电条件下具有更高的放电平台，在10mA、20mA、30mA、40mA放电条件下分别可以达到1.38V、0.65V、0.62V、0.58V。本论文所有空气电极的制备均采用扩散层-集流体-扩散层-催化层的构型，以增强氧气的扩散能力，减少集流体的腐蚀和电解液的泄露，这样可以提高电池的放电性能。关键词：铝-空气电池；石墨烯；氧还原；催化剂哈尔滨工业大学理学硕士学位论文IAbstractAluminum-airbatterybasedonthe(anodeAlmetal|electrolyte|cathodeoxygen)configuration,owingatheoreticalopen-circuitvoltageof2.73Vandspecificenergy(8.1kWh/kgofAl;2.8kWh/kgofcellreactants),haveattractedworldwideattentionasapromisingpowersourceforlarge-scaleapplicationssuchaselectricvehiclesandstationaryenergystorage.Whilethenatureofthecatalystplaysakeyroleintheoverallperformanceofaluminum-airbatteryandtheincreaseoftheactivityofcathodematerialsforafewtimeshigherisaformidablechallengethatrequiresafundamentalbreakthrough.Graphenenanosheets(GNS)haveshownedgreatpromiseinmanyapplications,becauseofitsuniquenanostructure,extraordinaryphysico-chemicalpropertiesandstrongmechanicalstrength.Inthispaper,GNShavebeenfirstemployedascatalyst’ssupportertomanufacturealuminum-airbattery.GNSwerepreparedbythermalexpansionmethod,andPlatinum-Cobaltalloynanoparticlesdepositedongraphenewerepreparedbyethyleneglycolreductionprocessundertheassistanceofthemicrowave.Thestructure,morphology,compositionandsurfacepropertiesoftheas-preparedcatalystsarecharacterizedbyX-raypowderdiffraction(XRD),transmissionelectronmicroscopy(TEM),scanningelectronmicroscope(SEM)andInfraredSpectroscopy(IR).moreover,Cyclicvoltammetry(CV),linearsweepvoltammetry(LSV)andconstantcurrentdischargewereusedtotesttheoxygenreductionelectrode.Theresultsshowedthatthegrapheneoxide(GO)madebypre-oxidedisbetterthannopre-oxidedprocedure,andwhenthetimeoficebathhavebeenincreased,GOwillhasbetterperformance.GNSmadebyusingPANIasmodificationhavebiggerBETsurfaceandbetteroxygenreductionreaction(ORR).Particleswereuniformlydispersedonthesurfaceofgraphene,andtheparticlesizewasabout3nmandexhibitedhighelectrochemicalactivity,whenthemassrationsofplatinumandcobaltare1:2.WhenGNScompositedwithXC-72andWMCNTrespectively,itcanimprovetheperformanceofthecatalyst.WhenGOtoXC-72qualityratiois4:1,theairbattery,atthesamedischargeconditions,haveahigherdischargeplatform.Inthedischargeconditionsof10mA,20mA,30mAand40mA,thedischargeplatformcanreach1.31V,1.0V,0.54V,0.48V.WhentheGOandtheratiooftheMWCNTqualityis2:1,Inthedischargeconditionsof10mA,20mA,30mAand40mA,thedischargeplatformcanreach1.38V,0.65V,0.62V,0.58V.Inordertoimprovethediffusionofoxyen,reducetheleakageofelectrolyteandthecorrosionofcurrent哈尔滨工业大学理学硕士学位论文IIcollector,weusethemodelofdiffusionlayer-currentcollector-diffusionlayer-catalystlayertomakethecathode.Keywords:aluminum-airbattery,graphene,chemicalreduction,catalyst哈尔滨工业大学理学硕士学位论文I目录摘要.................................................................................................................................IAbstract...............................................................................................................................I第1章绪论.................................................................................................................11.1铝-空气电池的研究进展......................................................................................11.2铝空气电池的工作原理.......................................................................................21.3铝-空气电池的结构与特点..................................................................................31.4铝空气电池空气电极的研究...............................................................................41.5空气电极典型催化剂...........................................................................................51.5.1廉价催化剂.....................................................................................................51.5.2金属有机大环螯合物...........................