鋰鎳鈷復合氧化物正極材料的制備與摻雜改性研究.pdf

1、天津大學碩士學位論文鋰鎳鈷復合氧化物正極材料的制備與摻雜改性研究姓名：高俊奎申請學位級別：碩士專業(yè)：化學工程指導教師：唐致遠徐強20061101ABSTRACTLithiumionbatteriesaremostpromisinghighpowersecondarybatteriesduetoitsadVantagesofhigherenergydensity，moresafety，longerlifetimesandnopolluti

2、onoverconventionalbatterysystemsAsthedemandforbetterperformanceoflithium—ionbatteriesincreases，findingnewmaterialscapableofimproVementonexistingtechnologyisoneofimportantmethodsLithiumcobaltoxidehasbeenwidelyusedasacatho

3、dematerialfIorcoInmercialsecondarylithium—ionbatteriesButthedeVelopmentoflithium—ionbatteryisinhibitedbecauseofscarcityofcobaltresources，toxicityandunfriendlyenvironmentBasedonameritofsolidsolutionwiththeformulaLiNilxCox

4、02whichcombinestheadVantagesofcobaltandnickelsystemmaterialsandthepartialsubstationofNiwithCocanstabilizethelithiumnickeloxidestructure，withinthisbodyofwork，layeredLiNio8Coo202issynthesizedbycoprecipitationmethodThemajor

5、performancesofLiNio8Coo202atdifferentpHValuesofsolution，calcinedtenlperature，calcinedtimeandlithiumsaltcontentwerestudiedThestructureandelectrochemicalperformanceofcathodematerialsweresystematicallycharacterizedbyacombin

6、ationoftechniqueswhichareTG—DSC，XRD，EIS，CVandSEMTheresultsshowthatLiNio8Coo202exhibitsahigherdischargecapacityof190mAh／gandgoodcycleperformanceatthepHValueof1l，thecalcinedtemperatureof900℃，thecalcinedtimeof6hours，andLioH

7、／M(oH)2=105InordertoimproVeperformanceofmaterial，layerLiNio8Coo202isdopedbydifferentdopantsTheVariationofthecellparametersandvolumeatdif佗rentchargedVoltagesofLi口呵i(1xy)Coxl嗎]02(M=AJ、Mn)showsthatthecontractionofcellVolume

8、ofAldopedissmallerthanthatofMndoped，ThecontractionissmallerandthestructureismorestablewithincreasingAlcontentDSCresultsshowthattheadditionofAlandMnimproVethethermalstabilityofmaterialsWithincreasingamountsofdopant，thedec