摘要
Cellulose,themostabundantorganicpolymeronEarth,isasustainablesourceofcarbontouseasanegativeelectrodeforsodiumionbatteries.Here,hardcarbons(HC)preparedbycellulosepyrolysiswereinvestigatedwithvaryingpyrolysistemperaturefrom700°Cto1600°C.CharacterisationmethodssuchasSmallAngleX-rayScattering(SAXS)measurementsandN2adsorptionwereperformedtoanalyseporositydifferencesbetweenthesamples.Thegraphenesheetarrangementswereobservedbytransmissionelectronmicroscopy(TEM):anorderingofthegraphenesheetsisobservedattemperaturesabove1150°Candsmallcrystallinedomainsappearover1400°C.Asthegraphenesheetsstarttoalign,theBETsurfaceareadecreasesandthemicroporesizeincreases.Tocorrelatehardcarbonstructuresandelectrochemicalperformances,differenttestsinNa//HCcellswith1MNaPF6ethylenecarbonate/dimethylcarbonate(EC/DMC)wereperformed.Samplespyrolysedfrom1300°Cto1600°Cshoweda300mAh/greversiblecapacityatC/10rate(whereC=372mA/g)withanexcellentstabilityincyclingandaverygoodinitialCoulombicefficiencyofupto84%.Furthermore,hardcarbonsshowedanexcellentratecapabilitywheresodiumextractionratevariesfromC/10to5C.At5Cmorethan80%ofreversiblecapacityremainsstableforhardcarbonssynthesizedfrom1000°Cto1600°C.
出版日期
2016年05月15日(中国期刊网平台首次上网日期,不代表论文的发表时间)