锂离子电池的碳导电添加剂

CIBF2005,April3rd,2005CarbonConductiveAdditivesforLithiumIonBatteries锂离子电池的碳导电添加剂MichaelE.Spahr,YeBingCIBF2005,April3rd,2005Outline大纲1.Introduction(介绍）•Whycarbonmaterialsasconductivematrix?为什么碳材料可以作为导电体•Roleofthecarbonconductivematrix,碳导电体的作用2.Graphiteasconductiveadditive石墨作为导电添加剂3.Carbonblackasconductiveadditive碳黑作为导电添加剂4.Graphiteorcarbonblack?选择石墨还是碳黑5.Conclusions结论CarbonconductiveadditivesforlithiumionbatteriesCIBF2005,April3rd,2005Carbonconductiveadditives碳导电添加剂Advantagesofcarbonadditivesinelectrochemicalapplications碳导电添加剂在电化学应用中的优点electricalconductivity导电性thermalconductivity(graphiteinparticular)导热性(特别是石墨)non-toxicandenvironmentallybegnin无毒环境友好availableinhighquantityandpurity高纯度chemicallyinert化学稳定性lowweight低重量relativelylowproductioncosts相对低的制造成本2.conductivecarbonblacks导电碳黑1.primarysyntheticandnaturalgraphitepowders原生合成和天然石墨粉(Xylenedensity:2.230-2.267gcm-3,二甲苯密度graphiteinterlayerdistance石墨层距c/2:0.3354-0.3360nm)CIBF2005,April3rd,2005Influenceofthecarbonconductiveadditive碳导电剂的影响1.Electrodeimpedanceoptimization电阻的最优化Increaseoftheelectronicconductivity增加导电性(mathematicallydescribedbythePercolationTheoryortheEffectiveMediumTheory渗透理论的数学描述)Ultimateresistivitylevel最终的电阻率Percolationcurve渗透曲线r[W*cm]0.11vol.%C51015Slope斜率Resistivityleveloftheelectrodematerial电极的导电Limitsforthinfilmelectrodes,butsuitableformaterialcomparisons对薄膜电极有局限性,但适用材料的比较CIBF2005,April3rd,2005Influenceofthecarbonconductiveadditive碳导电剂的影响Increaseoftheionicconductivity增加离子导电性(electrolyteretentionandlithiumiontransportrateintheelectrodepores电解液的保持和在电极孔中锂离子的传送速率)-electrolyteabsorption电解液的吸收-controlofelectrodeporestructure电极多孔结构的控制2.Energydensityoptimization能量密度的最优化•electrodedensity(compactionproperties)电极密度(压实性)•electrolyteandpolymerbindercontent(polymer/electrolyteabsorption)电解质和高分子粘接剂的含量•electrochemicalandchemicalsidereactions(surfacearea)电化学和化学副反应3.Electrodemanufacturingprocess(slurrypreparation)电极生产过程(制浆)-viscositycontroloftheslurry(solventabsorption)浆料的粘度控制-dispersibilityintheliquidmedia分散在液体介质中1.Electrodeimpedanceoptimization电极电阻的最优化CIBF2005,April3rd,2005Graphitemanufacturingprocess石墨生产过程Primarysyntheticgraphite原生石墨selection,crushingMixing,筛选,粉碎,和混合Graphitization石墨化Carbonprecursor碳前体Rawmaterialmix初混物Naturalgraphite天然石墨Graphiteore矿石crushing,grinding,Flotation,粉碎,研磨,浮选Rawgraphite(max.98%C)初产品Rawpurifiedgraphite(min.99%C)初纯石墨thermal/chemicalPurification热/化学纯化conditioning,grinding,classifying,mechanical/chemicaltreatment,处理,研磨,分类,机械/化学处理Finalgraphiteproduct产品CIBF2005,April3rd,2005Graphitemanufacturingprocess石墨生产过程Syntheticgraphite合成石墨Temperature[1000°C]050100150200Crystallitesize[nm]晶体尺寸3TIMREX®GraphiteTIMREX®Coke21Graphitizationprocess石墨化过程CIBF2005,April3rd,2005Graphitematerialproperties石墨性能Purity纯度Crystallinity晶体Texture/Porosity质地/多孔性Particlesize/Particleshape颗粒尺寸/颗粒形状Surface表面Properties性能CIBF2005,April3rd,2005Graphitematerialproperties石墨性能c/2=.3354nm0a=0.246nml=0.1421nmABAPrismaticSurfaceBasalPlaneSurfaceHexagonalRombohedralABCAc=1.0072nmGraphitecrystalstructure石墨的晶体结构CIBF2005,April3rd,2005Graphitematerialproperties石墨性能TIMREX®SFG441mmGraphitetexture石墨质地Anisotropicproperties各向异性Isotropicproperties各向同性Polycrystallineparticles多晶颗粒CIBF2005,April3rd,2005Graphitematerialproperties石墨性能GraphiteporosityTypeIII-isothermeIII型等温线mesoporousmaterial间孔材料(Brunauer,Emmett,Teller)•surfaceroughness表面粗糙度•porosity多孔性•geometricalsurfacearea几何表面积Totalgraphitesurfacearea石墨表面积•surfacedefects表面缺陷0.00.20.40.60.81.00246810Vads.[[cm3]]Pressure[p/760Torr]N2-adsorptionN2-desorptionCIBF2005,April3rd,2005Graphiteconductiveadditives-positiveelectrode正极石墨导电剂球面电阻PelletresistivityofLiCoO2BCathodebarUII456789100.00.20.40.60.81.01.21.4电阻[Wcm]石墨含量[%]KS6KS15SFG15MX15CIBF2005,April3rd,2005Graphiteconductiveadditives-negativeelectrode负极石墨导电剂020406080100100150200250300350400Specificcharge[mAh/g]CyclenumberLi+insertionLi+de-insertionMCMB/SFG6MCMBElectrolyte:1MLiPF6inEC/DMC(1:1)Graphiteadditivesinthenegativeelectrode石墨在负极中Binder:10%PVDFCIBF2005,April3rd,2005Graphiteconductiveadditives-negativeelectrode负极石墨导电剂01002003004000.00.20.40.60.81.01.21.4SpecificCharge[mAh/gCarbon]Potentialvs.Li/Li+[V]1MLiPF6inEC/DMC1:1(w:w)10%PVDFbinderTIMREX®SFG4410mmDoublefunctionintercalationhost双重功效嵌入主体CIBF2005,April3rd,2005Graphiteconductiveadditives-negativeelectrode负极石墨导电剂0246810121416182002468101214161820222426IrreversibleCapacity[%]SpecificBETSurfaceArea[m2/g]KS-typeSFG-typeT-typeSLM-typeSLX-typeNP-typeInfluenceofthespecificBETsurfacearea比表面积的影响1MLiPF6inEC/DMC1:1(w:w)10%PVDFbinderCIBF2005,April3rd,2005Graphiteconductiveadditives-negativeelectrode负极石墨导电剂Compatibilitywithpropylenecarbonate丙烯碳酸盐的相容性0.00.51.01.52.00.00.51.01.5Potentialvs.Li/Li+[V]xinLixC6SFG6SFG15SFG44Electrolyte:1MLiPF6inEC/PC1:1(w:w)CIBF2005,April3rd,2005Graphiteconductiveadditives-electrodeprocessing石墨导电剂-电极加工0510152025050100150200250DBPA[g/100gC]BETSSA[m2g-1]Isometric各向同性Anisometric各向异性KS4KS6KS15SFG6SFG15SFG44MX15D90%[mm]4.86.517.06.518.048.018.0Scottdensity[gcm-3]0.050.070.100.060.090.190.06CIBF2005,April3rd,2005Graphiteconducti