锂离子电池三元复合正极材料的合成及其电化学性能研究

《锂离子电池三元复合正极材料的合成及其电化学性能研究》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。

1、重庆大学硕士学位论文锂离子电池三元复合正极材料的合成及其电化学性能研究姓名：牛晓波申请学位级别：硕士专业：物理化学指导教师：朱伟20061008重庆大学硕士学位论文中文摘要其最佳合成条件为Ni／Co／Mn比例为O．1：0．2：O．5(摩尔比)、Li／('Ni+Co+Mn)为1．50：l(摩尔比)，煅烧温度和煅烧时间分别为850℃、8h，形成了在空气中直接合成出镍钴锰复合正极材料的新工艺。XRD和电性能测试表明，该正极材料具有类似LiNi02的层状结构(a-Nare02型六方层状结构，属R3m空间群)，结晶度良好，具备了放电比容量高、循环稳定性能好的特点，其电化学性能接近国

2、外同类正极材料研究水平。关键词：锂离子电池，镍钴锰复合正极材料，合成，电化学性能Ⅱ重庆大学硕士学位论文英文摘要ABSTRACTAsanewgenerationcathodematerial，LiNixCoyMnt．x-y02cathodematerialhasgreatpotentialforbeinganewbndofcathodecandidateforitsexcellentelectrochemicalperformanceandlowcost,showinganattractiveprospectatminitype-portableelectric∞urc髓a

3、ndla唱伊scalepowersupplies．Forthesereasons，LiNixcoyMnl．I舡hasbeenstudiedintensivelyasacathodematerialtoreplacethepresentlyusedLiC002．However,theelectrochemicalperformanceofLiNixCoyMni．x．y02hasbeengreatlyaffectedbytheoxidationofNi”andMn3+,andthelayeredstructureofthematerialishardtobesynthesiz

4、ed．Recently,LiNixCo#Inl《-y02cathodematerialismadebybeingcalcinedatmorethan900"Cformorethan10hours,andthistechnicsisSOcomplexthatitmakesthiskindofmaterialhardtobeapplyinginmdllstry．Furthermore,forthiscathodematerialisstudiedforonlyafewyears，therearenotmanyreportsonitandthedischargecapacity

5、ofthiskindofmaterial，ofwhichismadeinourcountry,isabout160mAh／g,whichmakestheindust：l=ializedproductionofLiNixCoyMnl．I-y02becomingimpossible．Forasolutiontotheseproblems，extensivestudieshavebeencarriedoutonthesynthesizingofLiNixCoyMnl．x-y02inthispaper．ThesampleLiNixCoyMnl《．y02，synthesizedin

6、airatmosphereandlowertemperature，showssatisfactoryperformance．Itsinitialdischargecapacityis197．6mAh／g,itsinitialdischargeefficiencyis73％，andme50也dischargecapacityonlydeceases1．3％，showinggoodelectrochemicalstabilities．Differedfrompresentcathodematerialsresearchthoughtandmethod,Wehavebrough

7、tforwardtheideaofemphasizingonthestudyoftheprecursor．WestudiesontheinfluenceoftheprecursoroftheLiNixCoyMlll．x-,02ontheslructureandelectrochemicalperformance．Inthispaper,sol—gelmethodhasbeenusedtosynthesizedtheprecursor．Therelationsbetweentheperformanceandcrystalstru