Preparation And Performance Of Novel Perovskite Cathode Materials BaCoFeNbO For Intermediate-temperature Solid Oxide Fuel Cells

In recent decades, thesearch forefficient,less pollutingenergystoragedevice hasattract-ed worldwide attention, with theenergy crisisand environmentalpollution is worsening.Solidoxidefuelcell(SOFC)isakindofH2,COandhydrocarbonssuchasnatural gasasfuel,environmentfriendly; And solid oxidefuel cellsare notCarnot cyclelimit, the energyconversionrate,therefore,developinganddevelopedahigh-performanceSOFC iscritical.SOFC work in process, reduce the cost of manufacture and use is very important. Thestudy found thatin theSOFCoperating temperature tolow temperaturecan reduce costs,butreduce theoperating temperaturewill causethe cathodepolarization resistanceandelectrolyteohmic resistanceincreased significantly,resulting in significantly reducedbatteryperformance, as the electrolytethin film technologyand highThe development of ionicconductivityof the electrolyte, the electroly teohmic resistancelosses of thelargelybeenalleviated, so toovercome theproblemscaused byloweroperating temperatureis toenhancethecatalytic activityand lower cathode over potentialcathode. Cathode output performanceofthe wholecell plays acrucial role, so the development of high performan-celow-temperaturesolid oxidefuel cell (IT-SOFC) cathode material isvery important.Electronion mixed conductive (MIEC)cathode cathode materialsresearch focusis now,because the MIECis not onlya high electronic conductivityand highionic conductivity,oxygen can participate in the eletrochemicalreduction reactionof theactive sitefromtheelectrode/electrolyte expansion. To the entirecathode surface, which canreducetheactivityofthecathodepolarization.Thissuperior performancefrom theselectedelectrode materialstarting to MIEC cathodematerialand thecomposite cathodematerials forstudy, working mainly onBaCo_0.7-xFe_xNb_0.1-O_3-δ(BCF_xN), BaCo_0.7Fe_0.2Nb_0.1O_3-δ(BCFN) and the GDC complex and BaxCo_0.7Fe_0.2-Nb_0.1O3-б(B_xCFN)series of sample studied, the main researchmaterials, structure,thermalresistance, electrochemical performance, etc, proofof such materials asintermediatetemperaturesolidoxidefuelcellcathodefeasiblesex.BaCo_0.7Fe_0.2Nb_0.1O_3-δ(BCFN)calciumoxideorewithaverygoodstateofoxygenpermea-bility, asSOFCcathodematerials with goods tructural stability and electrochemical performance, but thecoefficient ofthermal expansionis relatively large, and not matchthetemperatureof theelectrolyteaffectthethermalcyclingofthebattery,inordertoimproveitsperformance, wechange thecontent of Fein theBbitto reducethe content ofthethermalexpansion coefficient, we usesolid phase synthesis BaCo_0.7-xFexNb_0.1O_3-δ(BCFxN,x=0.1,0.2,0.3,0.4,0.5)cathode materials, the studyfound10 hoursafter 1100oC after burning,BCFxN materials have been formedorthogonalstatesof calcium mineralstructure. WhentheFecontent ofthe same,as the temperature rises, the conductivityincreased,intemperatureunder certain conditions, with the Fe content increased, the conductivitydecreased. BCFXNaverage thermal expansion coefficientof sampleswiththe doping amountof Fe increasedslightly increases,when theFecontent of x=0.2 reached the maxi -mum,and then continue to increaseas theFecontentis reduced.Withthe increase of Fecontentinthe cathode polarization resistanceinterface(RP)first decreases and then increases, whentheFe contentxis0.2, RPvalue of theminimum, in the 600oC, 650oC, 700oC,750oCand800oCwhenthe interfaceThe valueof the corresponding resistorRPis0.07758,0.03118, 0.0176, 0.01274 and0.0093Ωcm2. Batterypower densityincreaseswithFecontent,the firstdecreases and then increases, when the Fecontentxis0.2, to showthe bestelectrochemical performance, Ni0.9Cu_0.1-SDCas the anode, SDCas the electrolyteof theelectrolyte support thesingle cellat 600,650, 700, 750, and 800oCmaximumoutput powerdensity153.15,239.68,329.68,408.16and511.15mW/cm2.BCFNand GDCelectrolyte materialswillblendwith the cathode material, the aim ofimprovingthe thermalcathodeand electrolytematching. In this paper solid phase synthesisBCFNcathodematerial,withglycine nitrate process (GNP) synthesis ofGDC, GDC afterBCFNand conductedby differentmass ratioblend of BCFN-xGDC(x=0,10,20,30,40)composite cathode materials, researchBCFNchemical compatlity with theGDC, GDCcontent onthe thermal expansion coefficient, microstructure and electrochemicalproperties.The results show that, BCFNwithnoadverse reaction betweenGDC, goodchemical compatibility.GDCaddingsignificantly reduce the thermal expansion coefficientofthe cathodematerial, cathodeand electrolyteto improvethe thermalcompatibility,whileimprovingthe microstructure of the material, expanding the lengthof three-phaseinterfaceand improve theelectrochemical properties ofthe material, when combined 30 wt%GDCcathodeshowedthe best performance,whentheRPwas onlyin800oC0.00693Ωcm2,thanpureBCFNcathodeRP(0.01449Ωcm2)ismuchsmaller.ToNi0.9Cu_0.1SDCastheanode,BCFN-GDC for thecathode, GDCelectrolytefor theelectrolyte supportedsingle cell, inthemaximum power density of 800oCrespectively 409.18, 425.78, 454.56, 557.59 and513.03 mWcm-2, whichthatBCFN-GDCisa promisingIT-SOFCcathodematerials.Asite ionsin thedefectlattice structureof perovskiteoxides,the physical and chemicalpropertiesof materialshave aserious impact. In this paper,prepared by solid BaxCo_0.7-Fe_0.2Nb_0.1O_3-δ(B_xCFN,x=0.95,0.98,1.0,1.02) series ofcathodematerials, B_xCFN measuredbyXRD,electrical conductivity, thermal expansion coefficient, impedance spectroscopy,electron microscopy (SEM) and single-celloutput power densityof thetest,the absenceoftheA-biton thecrystal structure, conductivity, thermal expansion properties, interfacialpolarizationresistanceand electrochemical performance. Foundby XRDresults, B_xCFN(x=1.0,0.98,0.95) 10 hours after 1000oC aftersintering,fully formed state Mine cubicstructure of calcium. Abitwith there duction ofBacontent inthe conductivitydecline in800oC time, Ba1.0Co_0.7Fe_0.2Nb_0.1O_3-δ hecon ductivity11.74572 S.cm-1,thatthe absence ofBa, mainly through themore oxygen.Forthe generation ofspacechargecompensation. halfcell impedance spectraand singlecell performanceresult show thatwhenthe800oCinterfacialpolarizationresistanceB0.95CFN/SDC0.0059Ωcm2,showedgoodcatalyticcathode.SDCas theelectrolytetothe electrolytesupportedsingle cell B0.95CFN|SDC|Ni0.9Cu_0.1SDCmaximumpowerdensityat800oCto750oCforthe465.05mW/cm2583.11mW/cm2.The basicstarting point ofthis paperis toreducethe thermalexpansion coefficienttoimprovethe performance ofthe cathodematerial, the use of A, B bits are combined reducethedoping andthe thermal expansioncoefficient ofthe cathode materialto improvethecathodeperformance.theexperimentalresultswell,afterasystematicstudy.