Title of article :
Anomalously Faster Deterioration of LiNi0.8Co0.15Al0.05O2/Graphite High-Energy 18650 Cells at 1.5C than 2.0C
Author/Authors :
Wei, Wenqing School of Mechanical-Electronic and Vehicle Engineering - Weifang University - Weifang , China , Cui, Dawei School of Mechanical-Electronic and Vehicle Engineering - Weifang University - Weifang , China , Wang, Jinlong School of Mechanical-Electronic and Vehicle Engineering - Weifang University - Weifang , China , Sun, Ailing School of Mechanical-Electronic and Vehicle Engineering - Weifang University - Weifang , China , Song, Hongmei School of Mechanical-Electronic and Vehicle Engineering - Weifang University - Weifang , China
Abstract :
Dischargerateisakeyparameteraffectingthecyclelifeoflithium-ionbatteries(LIB).Normally,lithium-ionbatteriesdeterioratemoreseverelyatahigherdischargerate.Inthispaper,wereportthatthecycleperformanceofLiNi0.8Co0.15Al0.05O2/graphitehigh-energy2.8Ah18650cellsisabnormallyworseata1.5Cdischargeratethanata2.0Cdischargerate.Combiningmacromethodswithmicromethods,thecapacity/rateperformance,electrochemicalimpedancespectroscopy(EIS),andscanningelectronmicroscope(SEM)morphologyoftheelectrodesaresystematicallyinvestigated.Wehavefoundthattheimpedanceofthenegativeelectrodesafter2.0Cagedissmallerthanthatafter1.5Caged,throughEISanalysis,andthedischargerateperformanceofthenegativeelectrodesafter2.0Cagedisbetterthanthatafter1.5Cagedthroughcoincellanalysis.Inaddition,somespecialmicrocracksinthenegativeelectrodesofagedcellsareobservedthroughSEManalysis,whichcanacceleratethesidereactionbetweenactiveandelectrolyteandformthethickerSEIwhichwillhindertheLi+insertionandcauseresistanceincrease.Inshort,theLiNi0.8Co0.15Al0.05O2/graphite-basedlithium-ionbatteriesshowbettercyclelifeata2.0Cdischargeratethanata1.5Cdischargeratewhichindicatesthatthenegativeelectrodescontributemorethanthepositiveelectrodes.
Keywords :
Anomalously Faster Deterioration , LiNi0.8Co0.15Al0.05O2/Graphite High-Energy 18650 Cells at 1.5C than 2.0C , Lithium-ionbatteries(LIB) , electricvehicles(EV)
