人造石墨与硅—石墨复合负极材料的制备与性能-研究

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1、PreparationandCharacterizationofArtificialGraphiteandSillicon—GraphiteCompositeAnodeMaterialsAbstract：Inordertomeettheincreasingrequirementsforhighenergydensity,high—ratecharge—dischargeabilityandlong—lifebatteries，twoaspectsofresearchwerecarriedout．Ontheonehand，improvingthes

2、tructureoftheartificialgraphitetoenhancethecycleperformance，especiallytherateperformanceofthegraphiteanodematerialbycontrollingthecarbonizationprocess；ontheotherhand，silicon(Si)wascompoundedwithgraphitetoovercometheapplicationlimitationofthelowtheoreticalspecificcapacityofgra

3、phite(372mAhg-i)，whichCanrealizecomplementaryadvantagesandmakeupeachother’Sshortcomings，andpreparenovelcompositeanodewithhighspecificcapacityandexcellentcyclingperformance．Artificialgraphiteswerepreparedusingtarcoalpitchbycarbonizingandgraphitizingmethod．Thefactorsofrawmateri

4、als，highestheatingtemperature，heatingrate，carbonizationtemperature，pre—carbonizationhavebeenstudiedtoobtaintheeasygraphitizationtarcoalpitchcoke，andtheartificialgraphiteswerepreparedaftersubsequentgraphitization．Theresultsshowthattheartificialgraphitepreparedbytarcoalpitchaft

5、eracarbonizationwithaheatingrateof1oC／minat700oChasthebestcycleperformanceatlowcurrentdensity．Theartificialgraphiteshowsaninitialreversiblecapacityof360．3mAhg。1withacapacityretentionrateof98．7％after50cycles．Whileapre—carbonizationat350oCwasaddedintheoptimumconditionsabove，the

6、artificialgraphiteachievedthebestrateperformancewitllareversiblespecificalcapacityof319．8mAhg～at10C．Usinggradedsuperfineartificialgraphitepowder(G<1岬)，Nano—sillicon(Si，<30nm)，heatedtarcoalpitch(P)andglucoseasrawmaterials，theeffectsoftwomethodsofaddingtarcoalpitchonthestructur

7、e，morphologyandelectrochemicalpropertiesofthecompositeshavebeeninvestigated．OneisspraydryingthemixtureofSi，Gglucoseandheatedtarcoalpitchtoobtainprecursorsandsubsequentpyrolysistosynthesizethecomposite．Theeffectsofsiliconcontent，calcinationtemperatureonthestructure，morphologya

8、ndelectrochemicalpropertiesofSi—G—P／Ccompositeshavebeenstudied．ItiSf