减少再堆叠改性的石墨烯薄膜在锂离子电池中的应用.pdf

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1、物理化学学~(WuliHuaxueXuebao1NovemberActa脚．一Chim．，z．2011，27(11)，2583—25862583[Article]www．whxb．pku．edu．cn减少再堆叠改性的石墨烯薄膜在锂离子电池中的应用杨晓伟何雨石廖小珍马紫峰(上海交通大学化学工程系，上海200240)摘要：对溶剂化的石墨烯薄膜进行冷冻干燥处理得到改性的石墨烯薄膜，这种处理可以降低干燥过程中石墨烯片层之间严重的再堆叠．结果表明改性的石墨烯薄膜具有更多的折皱和更大的层间距。并提高了电化学性能．在电流密度为50mA·g。时，该电池首次循环的放电和充电比容量分别为1

2、189．3和645．2mAh·g～，400次循环后充电比容量仍然超过305mAh·g～，显著高于使用传统真空过滤得到的石墨烯薄膜的电化学性能．此外，相对于传统的石墨电极(包括活性物质、聚合物粘结剂和导电集流体)，石墨烯薄膜电极的质量和成本有明显的下降．关键词：石墨烯薄膜：冷冻干燥：再堆叠：电极：锂离子电池中图分类号：0646ImprovedGrapheneFiImbyReducingRestackingforLithiumIonBatteryApplicationsYANGXiao—WeiHEYu-ShiLIAOXiao-ZhenMAZi—Feng(Department

3、ofChemicalEngineering,ShanghaiJiaoTongUniversity,Shanghai200240,PR．China)Abstract：Wepreparedimprovedgraphenef¨msbyfreezedryingsolvatedgraphenef¨ms，whichgreatlyreducedtheseriousrestackingofgraphenelayerswhentheywereface—t0一facestacked．Theresultsshowthattheimprovedgraphenef¨mhadmorecorruga

4、tionsandaIargerinterplanardistancethantheusuaIgraphenef¨mspreparedbyvacuumfiltrationleadingtoimprovedelectrochemicalperformance．Thedischargeandchargecapacitiesofthebatterywere1189．3and645．2mAh·g～．respectively。forthefirstcycleat5OmA·g～andthechargecapacityremainedabove305mAh·gaf【er400cycle

5、s．ThesevaluesarehigherthanthoseofthegraphenefiImpreparedbyvacuumfiltration．Moreover．themassandcostoftheelectrodewerereducedsignificantlycomparedwiththecommerciaIgraphite．basedanode．whichismadebycoatingamixtureofanactivematerial，apolymericbinder。andanelectriccurrentcollector．KeyWords：Grap

6、henefilm：Freezedrying；Restacking；Electrode；Lithiumionbattery1lntroductioncells，～hydrogenstorage，andcapacitors．一“Inparticular,weGraphenehasattracted仃emendousattentionfrombothfun．andothergroupshavedemonstratedgraphene·-basedanodesex·-damentalandappliedsciencecommunitiessinceitwasfirstlyhib

7、itingtheenhancedlithiumstoragecapacitiesandgoodcy-reportedin2004．。。Graphene—basedmaterialshavesuperiorclingperformances．一electricconductivity,highsurfaceareas，chemicalstability,andGraphenepaperisoneofbulkmaterialsassembledbyindi—abroadelectrochemicalwindowwhichareadvantag