欢迎来到天天文库
浏览记录
ID:57441591
大小:25.40 KB
页数:3页
时间:2020-08-17
《电化学理论知识英文版重要.docx》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、2.TypesofEESSsandtheirworkingprinciplesTheworkingmechanismofanyEESSreliesonaninherentpotentialdifferencebetweentwoelectrodesknownastheoperatingvoltage.Theoperatingvoltageofthedeviceisdictatedbythedifferencesinredoxpotentialofthepositiveandnegativeelectrode.Thepotentialdifferenceisusedtodriveelectro
2、chemicalreactionsoneitherelectrodewhentheyareconnectedthroughanexternalcircuit.Thiscreatesaflowofelectronsfromthenegativeelectrodetothepositiveelectrode.Theflowofelectronsinducesoxidationreactionsonthenegativeelectrode(anode)andreductionreactionsonthepositiveelectrode(cathode)whendischarging.The
3、chargedelectrodesarebalancedbyaconcomitantflowofcounter-ions.EESSsaregroupedintoanumberofdifferentcategoriesdependingonthecompositionoftheelectrodes,thecounter-ions,andthenatureoftheredoxreactions(Fig.1).2.1Solidelectrodebatteries2.1.1Metal-ionbatteryworkingprinciple.Batteriesoperatewithaconstant
4、voltagedefined,approximately,bythepotentialdifferencebetweentheanodeandcathode.Becauseofthis,Inagalvanostaticcharge/dischargeexperimentthepotentialoftheelectrodeordeviceideallyremainsconstantuntiltheactivematerialhasbeenfullyreduced(oxidized).Inacyclicvoltammogramexperiment,oneobservesareversible
5、,sharpredoxpeakwhenaredoxeventoccurs(insetFig.1a–c).Metal-ionbatteriesarethemostcommontypeofEESSs.Theyaretypicallycomposedofananode(negativeelectrode),acathode(positiveelectrode),electrolyte(eitheraqueous,organic,solid-state,18orpolymeric10,19),aseparator(topreventshortcircuiting),currentcollect
6、ors(tocollectchargeateachelectrode),andacellcasing(tokeepthecomponentstogetherandpreventexposuretotheexternalenvironment).Metal-ionbatteriesareusedforawidevarietyofbothportableandstationaryapplicationsforeitherprimaryorback-uppower.Inmetal-ionbatteriesthechargedanodesandcathodesarebalancedbythem
7、etalionina‘rocking-chair’typemechanism(Fig.1a).Thisisastrictrequirementimposedbythedefinitionofmetal-ionbatteriesthatshouldbeclearlydistinctfromdual-ionbatteriesdescribedbelow.Metal-ionbatteriescanbeconstructedwithrelatively
此文档下载收益归作者所有