采用机械球磨法制备BaFeSi/C复合物,并考察了其作为锂离子电池负极材料的电化学性能.结果表明,这种复合材料具有较高的初始放电容量、合适的充放电平台和良好的循环可逆性.XRD和XPS研究证明:BaFeSi/C复合物循环性能的提高主要源于惰性导电组分FeSi2、BaSi2和外层石墨骨架的协同作用,它们的存在不仅有效地缓冲了活性组分硅的体积变化,同时在很大程度上增强了复合材料的电子导电性和离子导电性.
A novel BaFeSi/C composite was prepared by mechanical ball milling, and lithium insertion reactions on the composite electrode were investigated by cyclic voltammetry ,charge-discharge measurements, XRD and XPS spectroscopy. It is demonstrated that the capacity retention with indiscernible capacity decas during charge-discharge cycling. The improved cycling ability of the composite is suggested from a cooperative action by inactive FeSi_(2 )and BaSi_2 matrix and outer graphite shell, which both buffer the volumetric changes of the active Si phase and provide a good connection for electronic and ionic conduction during lithium insertion and extraction processes.
[1] TiradoJL.Mater.Inorganicmaterialsforthenegativeelectrodeoflithium ionbatteries:state oftheartandfutureprospects[J].Sci.Eng.R,2003,40:103.
[2] HugginsRA.Alternativematerialsfornegativeelectrodesinlithiumsystems[J].SolidStateIonics,2002,152～153:61.
[3] BenedekR,ThackerayMM.Lithiumreactionswithintermetallic compoundelectrodes[J].J.PowerSour.,2002,110:406.
[4] WachtlerM,BesemhardJO,WinterM.Tinandtin basedintermetallicsasnewanodematerialsforlithiumioncells[J].J.PowerSour.,2001,94:189.
[5] CochezMA,JumasJC,LavelaP,etal.Newtin containingspinelsulfideelectrodesforambienttemperaturerockingchaircells[J].J.PowerSour.,1996,62:101.
[6] ElidrissiML,CorredorJI,TiradoJL,etal.SnHPO4:apromisingprecursorforactivematerialasnegativeelectrodeinLi ioncells[J].Electrochim.Acta,2001,47:489.
[7] LiH,HuangXJ,ChenLQ,etal.AHighcapacityNano Sicompositeanodenaterialforlithiumrechargeablebatteries,[J].Electrochem.Solid StateLett.,1999,(2):547.
[8] CaoYL,XiaoLF,AiXP,etal.ThemechanismofoxygenreductiononMnO2 catalyzedaircathodeinalkalinesolution[J].Electrochem.Solid StateLett.,2003,(6):A30.
[9] BourderauS,BrousseI,SchleichDM.AmorphoussiliconasapossibleanodematerialforLi ionbatteries[J].PowerSour.,1999,81～82:233.
[10] DimovN,KugnoS,YoshioM.Carbon coatedsiliconasanodematerialforlithiumionbatteries:advantagesandlimitations[J].Electrochim.Acta,2003,48:1579.
[11] DimovN,FukudaK,UmenoT,etal.Characterizationofcarbon coatedsilicon:structuralevolutionandpossiblelimitations[J].J.PowerSour.,2003,114:88.
[12] KimIS,BlomgrenGE,KumtaPN.NanostructuredSi/TiB2compositeanodesforLi ionbatteries[J].Electrochem.Solid StateLett.,2003,(6):A153.
[13] YangJ,WangBF,WangK,etal.Si/Ccompositeforhightcapacitylithiumstoragematerials[J].Electrochem.Solid StateLett.,2003,(6):A154.
[14] Ein EliY,ThomasSR,KochVR.NewelectrolytesystemforLi ionbattery[J].J.Electrochem.Soc.,1996,143:L195.
