SrCo0.9-xMxNb0.1O3-δ(M=Fe, Ni)电极的制备及氧还原性能研究

摘要本文重点研究了SrCo0.9-xMxNb0.1O3-δ(x=0.2,M=Fe,Ni) （统称SCN 包括SCFN 与SCNN)阴极材料的氧化还原性能，讨论了其成为新型中温SOFC（ITSOFC）阴极材料的可能性。本文通过固相法制备阴极粉体和Ce0.8Sm0.2O2-δ（SDC）电解质，所制粉体粒度在1-10 微米级，并通过扫描电镜分析、热重分析、电导率分析、X 射线衍射分析、间接碘量法测量的氧空位含量、电化学性能测试等表征阴极的性能。研究发现，所制粉体均已烧结成纯相；SCFN 的电导率在350℃达到最大为260 S•cm-1，保证了其在中温下工作的可能性；制备的SCFN、SCNN 粉体室温下的氧空位δ分别为0.262 和0.299，氧空位浓度较大，可以有效提高氧离子迁移速度，提高电池性能；SCFN与SCNN 对称电池的极化电阻在800℃分别为0.09、0.07 Ω•cm2；SCFN 与SCNN 单电池的功率密度在800℃时则达到了42、97mW•cm-2。这些结果表明SCN 是一种潜在的新型ITSOFC 阴极材料且SCNN 的性能较SCFN 更好。49111
毕业论文关键词SrCo0.9-xMxNb0.1O3-δ(M=Fe, Ni)阴极固相法极化电阻功率密度间接碘量法氧空位含量
Title Preparation and Study on the Performance of OxygenReduction of SrCo0.9-xMxNb0.1O3-δ(M=Fe, Ni) Electrode
Abstract This paper focuses on the redox properties of SrCo0.9-xMxNb0.1O3-δ(x=0.2, M=Fe, Ni)(SCN,including SCFN and SCNN) cathode materials, and we discussed its possibility to become a newtype of ITSOFC cathode material. In this paper, solid phase methods have been used to preparecathode powders and Ce0.8Sm0.2O2-δ electrolyte(SDC),whose particle size are within 1-10micro-level. Then we used conductivity, XRD, thermalgravimetric analysis, electrochemicaltests , SEM and oxygen vacancy content measured by the indirect iodimetry to characterize theproperties of cathode powders. Our study found that the powders we prepared has beencrystallized into pure phase,and the conductivity of SCFN reached maximum 260 S•cm-1at350℃which has guaranteed its possibility of working at intermediate temperature.The oxygenvacancy content in other words δ of SCFN and SCNN powders we prepared are 0.262 and 0.299at room temperature, respectively, that shows the oxygen vacancy concentration is considerablewhich can improve the oxygen ion migration velocity effectively and thus improve theperformance of the cell. In addition, the polarization resistance of SCFN and SCNN symmetriccell reached 0.09 and 0.07 Ω•cm2at 800℃respectively. Moreover the power density of SCFNand SCNN single cell reached 42 and 97 mW•cm-2. All the results indicate that SCN material isa new potential cathode material for ITSOFCs and SCNN is more preferred.Keywords SrCo0.9-xMxNb0.1O3-δ(M=Fe, Ni) solid phase methods polarization resistancepower density indirect iodimetry oxygen vacancy concentration

1绪论1

1.1引言..1

1.2SOFC的工作原理1

1.3SOFC的特点..2

1.4SOFC的组成与结构3

1.4.1SOFC的主要组成..3

1.4.2SOFC的结构模式..5

2实验与表征6

2.1实验原料和实验仪器.6

2.1.1实验原料..6

2.1.2实验仪器..7

2.2材料合成7

2.3样品制备9

2.3.1电解质片的制备..9

2.3.2电极浆料的制备..9

2.3.3对称电池的制备..9

2.3.4单电池的制备.10

2.3.5电化学测量样品的制备10

2.4测量所用设备仪器10

2.4.1X射线衍射仪.10

2.4.2热重（TG）分析..11

2.4.3SEM分析..11

2.4.4交流阻抗谱..11

2.4.5单电池性能测试11

2.4.6电导率测试..11

2.5氧空位浓度测试.22

2.5.1间接碘量法简介22

2.5.2溶液的配制..13

2.5.3滴定精度的标定13

2.5.4样品的滴定..14

3结果与讨论.16 SrCo0.9-xMxNb0.1O3-δ(M=Fe, Ni)电极的制备及氧还原性能研究:http://www.751com.cn/cailiao/lunwen_51958.html