ElectrochemicalBehaviorofLa-dopedLiFePO4/CCathodeMaterialsforLithiumIonBatteries

AlienatomwasusedtoobtainaseriesofLiFe1-xLaxPO4/C(x=0,0.002,0.005,0.01,0.015)cathodematerialswiththeaimofinvestigatingtheinfluenceofparticipationofLaontheelectrochemicalbehaviorofLiFePO4/C.CombinationofX-raydiffractometer,scanningelectronmicroscopeequippedwithenergydispersivespectrometerandhighresolutiontransmissionelectronmicroscopewasapplied.TheresultsshowthatalltheLa-dopedLiFePO4/Csamplesareolivinetypecrystals,Laionissufficientlyintroducedintothenetwork,andeveryelementiswellhomogeneouslydistributed.Therearemanyporespacesonthesurfaceofparticles.Thecontentofcarboninthepreparedcathodematerialsremains13.6%calculatedbyTGA/DTAcurves,andtheparticlesarewrappedbyauniformlyandcontinuouscarbonlayerwiththethicknessofabout2nm.Similarly,thecontentofFe2Palsokeepsthesamebasicallyinallthecathodematerialsasaresultofthesimilarratio(2.35)ofpeakintensityat36.5oand37.1ofromXRD.Theincreasingtrendismostpronouncedatdoped0.005whichpresentsthehighestinitialdischargecapacityof163mA×h/g,lowestchargetransferresistanceof5.52W,superiordiffuseabilityoflithiumion(10-11cm2/s)andthebestcapacityretentioncurrentrateofabout93%after50cyclesat0.1C.