Relevance of LiPF6 as Etching Agent of LiMnPO4 Colloidal Nanocrystals for High Rate Performing Li-ion Battery Cathodes
LiPF6作为高速率锂离子电池阴极用LiMnPO4胶体纳米晶刻蚀剂的相关性
出版日期:2016
作者单位:LinChen?,EnricoDilena?,AndreaPaolella§,GiovanniBertoni?∥,AlbertoAnsaldo?卷号:8
期数:6
刊号:1944-8244
出版日期:2016
简介:LiMnPO4isanattractivecathodematerialforthenext-generationhighpowerLi-ionbatteries,duetoitshightheoreticalspecificcapacity(170mAhg–1)andworkingvoltage(4.1VvsLi+/Li).However,twomaindrawbackspreventthepracticaluseofLiMnPO4:itslowelectronicconductivityandthelimitedlithiumdiffusionrate,whichareresponsibleforthepoorratecapabilityofthecathode.Theelectronicresistanceisusuallyloweredbycoatingtheparticleswithcarbon,whiletheuseofnanosizeparticlescanalleviatetheissuesassociatedwithpoorionicconductivity.ItisthereforeofprimaryimportancetodevelopasyntheticroutetoLiMnPO4nanocrystals(NCs)withcontrolledsizeandcoatedwithahighlyconductivecarbonlayer.Wereporthereaneffectivesurfaceetchingprocess(usingLiPF6)oncolloidallysynthesizedLiMnPO4NCsthatmakestheNCsdispersibleintheaqueousglucosesolutionusedascarbonsourceforthecarboncoatingstep.Also,itislikelythattheimprovedexposureoftheNCsurfacetoglucosefacilitatestheformationofaconductivecarbonlayerthatisinintimatecontactwiththeinorganiccore,resultinginahighelectronicconductivityoftheelectrode,asobservedbyus.ThecarboncoatedetchedLiMnPO4-basedelectrodeexhibitedaspecificcapacityof118mAhg–1at1C,withastablecyclingperformanceandacapacityretentionof92%after120cyclesatdifferentC-rates.ThedeliveredcapacitieswerehigherthanthoseofelectrodesbasedonnotetchedcarboncoatedNCs,whichneverexceeded30mAhg–1.TheratecapabilityherereportedforthecarboncoatedetchedLiMnPO4nanocrystalsrepresentsanimportantresult,takingintoaccountthatintheelectrodeformulation80%wtismadeoftheactivematerialandtheadoptedchargeprotocolisbasedonreasonablefastchargetimes.
