鋰離子電池正極材料LiFePO-,4-的合成與性能研究.pdf

1、rIIllflllrlfrlll／r／H／rrlrlllIP：lllrlllllllY1436759分類號：——UDC：——工學碩士學位論文密級：——編號：——鋰離子電池正極材料LiFeP04的合成與性能研究碩士研究生：指導教師：學位級別：學科、專業(yè)：所在單位：論文提交日期：論文答辯日期：學位授予單位：張維維陳猛副教授工學碩士應用化學材料科學與化學工程學院2008年5月2008年6月哈爾濱工程大學哈爾濱r稗人學碩十學侍論文I●__—●●

2、lIl●_●lll_II●IliIII__IiIN—I—●———一ABSTRACTLithiumIronPhosphate(LiFeP04)hasbecomemoreandmoreconcernedforitsSOmanyobviouscharacterssuchasnontoxic，environmentalfriendlylowrawmaterialcost，highspecificcapacityexcellentcycleper

3、formanceandsafetyanditisconsideredtobethemostpromisingcathodematerialforLithiumIronbatteryHoweverbecauseofthelowelectronicconductivitythepoorhighrateperformanceshouldbeimprovedInordertodecreasingtheproductioncostandenhan

4、cingthehighrateperformanceofthismaterial，thispaperadoptedliquidphasecarbothermalreductionmethodtoimproveLiFeP04’sbehaviorbymainlyusingcarboncoatedandMdopedmethodItisfoundthatwecallmoreeasilyobtainthegoodbehaviormaterialu

5、ndertheconditionsof20％carboncoating，7009Csinteringtemperature，aftertestingtheinfluenceofcarboncoatingcapacityandthedifferentsinteringtemperatureSingleandbinaryiondopingWascardedouttoimproveperformaceofLiFePOdCcompositesy

6、nthesizedbyliquidphasecarbothermalreductionmethodItisshownbyXRDtestthatthepreparedmaterialsweresingleolivestructure，noimpurityisobservedinthemandthedopingionenteredintoinsideofcrystallatticebysubstitutingsomeofFEZ；SEMfig

7、uresindicatedthattheparticleshapeandsizewasbetterthanthatofthematerialswhichwerenotdoped；InthisstudythecyclicpropertyofLiFe095Coo05P04singledopingmaterialisbest，itcouldexport12884mAh’g～ofthespecificcapacityatinitialcycle

8、andremain9337％ofinitialcapacityafter40cyclesAtthesametime，theradiusofthedopedNi2，Mn3，MgareclosedtoFe2，SOtheionswereusedtosubstituteFe2TheresulttoldthattheNidopingcallexcellentlyimprovetheelectronicconductivityofsamples，s