液态软包装锂离子电池工艺与隔膜的研究

工学硕士学位论文液态软包装锂离子电池工艺与隔膜的研究袁春刚哈尔滨工业大学2006年6月图书分类号：TM911.3U.D.C.:621.35.035工学硕士学位论文液态软包装锂离子电池工艺与隔膜的研究硕士研究生：袁春刚导师：杨哲龙教授申请学位级别：工学硕士学科、专业：应用化学所在单位：应用化学系答辩日期：2006年6月授予学位单位：哈尔滨工业大学ClassifiedIndex：TM911.3U.D.C.:621.35.035DissertationfortheMasterDegreeinEngineering.RESEARCHONSOFTPACKAGINGLITHIUM-IONBATTERYARTSANDCRAFTSANDSEPARATORCandidate：YuanChunGangSupervisor：Prof.YangZheLongAcademicDegreeAppliedfor：MasterofEngineeringSpecialty：AppliedChemistryAffiliation：DepartmentofAppliedChemistryDateofDefence：June,2006Degree-Confferring-Institution：HarbinInstituteofTechnology哈尔滨工业大学工学硕士学位论文摘要本课题主要研究液态软包装锂离子电池的工艺及隔膜的制备方法，目的是开发出循环性能和安全性能均达到商业化要求的液态软包装锂离子电池。液态软包装锂离子电池的研究主要是对关键工艺进行了优化设计，具体包括：集流体的处理、PVdF的加入量、浆料搅拌时间和粘度、导电剂的加入量、电极膜的厚度、不同集流体的选择、电极膜的干燥程度、压型的厚度、电解液的加入量、注入电解液后静置时间的长短、化成制度的影响、化成时电池所具有的压力影响、抽真空的处理、正负极活性物质的匹配。昀后确定出液态软包装锂离子电池昀佳工艺参数：正极膜的厚度小于90µm；根据化成时不同抽真空顺序，确定正极膜中的导电剂的加入量分别为5mass%和9mass%；负极膜中导电剂的加入量为2mass%；电解液的加入量为每100mAh添加0.4mL；化成前电池的静置时间应当大于8h；电池在3.0V之前采用小于0.01C的化成制度；在化成过程中应当施加一定的外部压力；对于350mAh的电池抽真空的延时不应大于15s；而正负极活性物质的质量比应当在2.1︰1~2.15︰1之间。昀后能够做出循环性能和安全性能都较好的液态软包装锂离子电池。论文对液态软包装锂离子电池隔膜的制备方法，也进行了初步的研究。选用的基体材料为PVdF，同时向其中添加棉纤维和淀粉，昀后利用100℃沸水对隔膜进行3小时蒸煮处理使淀粉溶胀，从而达到造孔的目的。在涂布工艺的筛选中，通过对麦腊片、铜箔、铝箔进行筛选，昀后选定以铜箔为载体来进行涂布处理。当以铜箔为载体时，可以使隔膜正反两面物理性质达到基本一致。加入棉纤维使隔膜的强度得到提高，因而能够克服隔膜容易出现微短路的现象，而且所组装的电池具有较好的循环性能。关键词:锂离子电池；液态软包装；工艺；优化设计；隔膜--I哈尔滨工业大学工学硕士学位论文AbstractThispaperaimistoresearchtheartsandcraftsofsoftpackagingLithium-ionbatteryandfabricateakindofseparatorwhichcanbeusedinsuchbatteries.Soastoexploiturecyclingperformanceandsecurityareallreachtothecommercialrequire.AlotofexperimentshavebeendoneintheprocessofexploituresoftpackagingLi-ionbatteryabouthowtochoicetherationalartsandcrafts.Thecontentinclude:howtodealwiththecollector,addhowmuchPVdFinthematerial,howlongthematerialneedtostirringandtherightviscidity,howmuchcondubtivityagenttheelectrodeneed,whatthecknessisbest,choicedifferentcollectors,thedegreeofdrynessoftheelectrode,thecknessofpressedmodel,howmuchelectrolytewillbeadded,placementhowlongafteraddedtheelectrolyte,systemofformationhowtoinfluncethebattery,informationthebatteryneedornotneedpreesurefromoutside,howtovacuumizeandtheoptimizematchingpositivepoleandnegativepole.Withthesepracticemakesuretheparameterofthepositivepoleshouldlessthan90µm;accordingtodifferentvacuumizeordertheconduc-tivityagentinanodewillbe5mass%and9mass%,respectively,andincathodethedatais2mass%;every100mAhaddedto0.4mLelectrolyte;beforeformationthebatteryshouldbeplacement8hoursandthesystemofformationmustbelessthan0.01Cbeforethevoltagereachto3.0V;shouldpressinoutsidewhenbatteryinformation;tothesebatterieswhichcapacitymorethan350mAhthevacuumtimenotexcess15s;theoptimizematchingpositivepoleandnegativepolebetween2.10:1and2.15:1.Finallymakeoutthebatterywhichcyclingperformanceandsecurityareallverywell.AtthesametimeIalsodidmanyprimaryexpermentsonseparatorandthesepolymermembranecanbeusedinassoftpackagingLi-ionbattery’sseparator.UsedPolyvinylideneFluoride(PVdF)asthebasicmaterial,addedcottonfibreandstarchin,cookedwith100℃inboilingwaterafer3hours,thestarchinflate,andthenacquireporouspolymermembrane.Intheprocessofcoatingpolyesterfilm,copperfoilandaluminumboilwereusedtoascarrier,--II哈尔滨工业大学工学硕士学位论文finallythecopperboilbechosen.Becausethemembranebothsideshavesimilarphysicalperformancethenusedthecopperboilasthecoatingcarrier.Suchmaterialmembraneeasilytobringtinyshortcircuitbutaddedthecottonfibreinmembranetheintensityofthemembaneincrease.Whenusedthiskindofseparatorinbatteryitsperformanceallveryfine.KeywordsLi-ionbattery,softpackaging,artsandcrafts,optimizedesign,separator--III哈尔滨工业大学工学硕士学位论文目录摘要.....................................................................................................................................IAbstract.................................................................................................................................II第1章绪论.....................................................................................................................11.1锂离子电池的发展概况.................................................................................11.2锂离子电池的基本原理.................................................................................21.3正负极材料.....................................................................................................21.3.1LiCoO2正极材料....................................................................................21.3.2其它正极材料..........................................................................................31.3.3石墨负极材料........................................................................................41.4电解质与隔膜.................................................................................................51.4.1电解质简介.............................................................................................51.4.2隔膜特点与制备......................................................................................61.5粘接剂导电剂和添加剂.................................................................................71.5.1粘接剂PVdF（聚偏氟乙烯）简