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研究生:安吉良
研究生(外文):Gilang Baswara Anggara Putra
論文名稱(外文):Higher-order Ruddlesden-Popper Phases of Mg-doping Lan+1Nin(1-x)MgnxO3n+1 (1≤n≤3 ; 0≤x≤0.04) Prepared by Combustion Process to Use as Cathode Material of Solid Oxide Fuel Cell
指導教授:林景崎
指導教授(外文):Lin, Jing-Chie
學位類別:碩士
校院名稱:國立中央大學
系所名稱:應用材料科學國際研究生碩士學位學程
學門:工程學門
學類:材料工程學類
論文種類:學術論文
論文出版年:2020
畢業學年度:108
語文別:英文
論文頁數:101
中文關鍵詞:Ruddlesden-Popper結構陰極材料固態氧化物燃料電池電化學性能
外文關鍵詞:Ruddlesden-Popper StructureCathode materialSolid Oxide Fuel CellElectrochemical properties
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La2NiO4的層狀Ruddlesden-Popper(RP)結構具有比其他固態氧化物燃料電池(SOFC)的陰極材料優異之電化學活性。本研究的主要目的是探討La2NiO4陰極材料摻雜Mg的多層Ruddlesden-Popper(RP)結構,該材料是通過甘氨酸-硝酸鹽燃燒法(GNP)製備。其化學式為〖La〗_(n+1) 〖Ni〗_(n(1-x)) 〖Mg〗_nx O_((3n+1)-δ),x為摻雜濃度,n為RP結構層數。本研究主要分為三個階段。第一階段是探討在La2NiO4中摻雜Mg的適當濃度,研究了四個Mg含量分別為x = 0、0.02、0.03和0.04,其縮寫為LNO,LN1M2,LN1M3和LN1M4。在這些樣品中,由於LN1M3(3%Mg摻雜之La2NiO4)具有高的非化學計量氧空位(δ)、高電導率(〜200 S / cm)和出色的電化學反應性,被認為是SOFC中最好的陰極材料。在第二階段中,製備較LN1M3多層之RP結構(n = 2&3),如:LN3M3,其棒狀顆粒的框架可有效的提升電導率(即σ〜800 S / cm),並降低極化電阻(Rp為1.41Ωcm2)。在最後階段,將樣品LN3M3絲網印刷在不同的SOFC鈕扣電池上,以研究其陰極性能,這些鈕扣電池具有不同的支撐類型(電解質支撐、陽極支撐)以及不同的電解質材料(BaCe0.6Zr0.2Y0.2O3,BCZY、(ZrO2)0.92(Y2O3)0.08,YSZ), 由I-V測試之結果得到了LN3M3陰極在YSZ陽極支撐電池中有最佳之功率密度為:Pmax 205 mW / cm2,並經由電化學阻抗分析(EIS),模擬等效電路得到極化電阻為:Rp 0.12Ωcm2。
Layered Ruddlesden-Popper (RP) structure such as La2NiO4 has superior electrochemical activity than other cathode material for Solid Oxide Fuel Cell (SOFC). The primary purpose of this work is to explore new cathode material with higher-order Ruddlesden-Popper (RP) structure Mg-doped La2NiO4 material, which produces via Glycine-Nitrate Process (GNP). The general chemistry formula is 〖La〗_(n+1) 〖Ni〗_(n(1-x)) 〖Mg〗_nx O_((3n+1)-δ) with x is doping concentration and n as the number of RP structure layers. Three phases were taken to achieve the purpose of this work. The first phase is to explore the appropriate concentration of Mg-doped in La2NiO4. Four samples with magnesium contents varying in x= 0,0.02,0.03, and 0.04, abbreviated as LNO, LN1M2, LN1M3, and LN1M4, respectively, were investigated. Among the specimens, LN1M3 (i.e., 3% Mg-doped La2NiO4) was found the best cathode material used in SOFC, due to high nonstoichiometric oxygen-vacancy (δ), high electrical conductivity (~200 S/cm) and excellent electrochemical reactivity. In the second phase, higher-order (n=2 &3) RP structure such as LN3M3 based on LN1M3 was formed to indicate a frame of rod-like particles to reveal good electrical conductivity (i.e., σ ~ 800 S/cm) and low polarization resistance (Rp at 1.41 Ωcm2). In the final phase, specimen LN3M3 was screen-printed on different SOFC button cells to study their cathodic performance. These button cells were different in configuration (one supported by electrolyte and another supported by anode) and distinct in electrolytes (one is BaCe0.6Zr0.2Y0.2O3, BCZY, and the other is (ZrO2)0.92(Y2O3)0.08, YSZ). The results of I-V testing demonstrate different maximum power density. LN3M3 in YSZ anode-supported cell achieved the best power density Pmax 205 mW/cm2 and polarization resistance Rp 0.12 Ωcm2. The simulation of equivalent circuits of the electrochemical impedance spectroscopy (EIS) is useful to understand the difference in power density.
National Central University Authorization of Thesis i
National Central Library Thesis Embargo Application ii
Advisor Recommendation of Graduate Student iii
Verification Letter from Oral Examination Committee iv
摘要 v
Abstract vi
List of Symbols and Abbreviations vii
Acknowledgments viii
Content ix
List of Figures xii
List of Tables xv
Chapter 1 Introduction 1
1.1 Overview 1
1.2 Research Motivation 2
Chapter 2 Theoretical Background and Literature Review 3
2.1 Introduction of the Fuel Cell 3
2.1.1 Principle and Introduction of SOFC 4
2.1.2 Construction of Solid Oxide Fuel Cell 6
2.2 Solid Oxide Fuel Cell Component 8
2.2.1 Electrolyte 8
2.2.2 Anode 9
2.2.3 Cathode 9
2.3 Cathode Material 10
2.3.1 Conduction Mechanism Responsible for the Cathodic Kinetics 10
2.3.2 Crystal Structure Required for Cathode Material 12
2.3.3 Synthetic Processes for Cathode Material 14
2.4 Electrochemical Analysis 18
2.4.1 DC Polarization Curve Principle (I-V Curve) 18
2.4.2 Electrochemical Impedance Spectroscopy (EIS) 20
2.5 Selection of Cathode Material 23
2.5.1 Evolution of the Cathode Material 23
2.5.2 Lan+1NinO3n+1 system phases and series for cathode materials of SOFC 25
2.5.3 Mg doping La2NiO4 series used to be cathode materials of SOFC 28
Chapter 3 Experimental Overview 30
3.1 Materials Used in the Experiments 31
3.2 Sample Preparation and Procedure 31
3.2.1 Cathode Powder and Paste Preparation 31
3.2.2 Electrolyte Preparation 35
3.2.3 Complete Cell Preparation 36
3.3 Characterization Equipment 36
3.3.1 X-Ray Diffraction (XRD) 36
3.3.2 Thermogravimetric Analysis (TGA) 37
3.3.3 Thermal Expansion Coefficient (TEC) 37
3.3.3 Four Point Probe DC 38
3.3.4 DC Polarization Curve Test Platform (I-V) 39
3.3.5 Electrochemical Impedance Spectroscopy (EIS) 39
3.3.6 Scanning Electron Microscopy (SEM) 40
Chapter 4 Results 41
4.1 Analysis of the Cathode Powder Crystal Structure 41
4.1.1 Diffraction Analysis of Mg-doped La2NiO4 (First order LN) 41
4.1.2 Diffraction Analysis of Mg-doped La2NiO4 (Higher-order 2nd and 3rd) 43
4.2 Thermogravimetric Analysis 45
4.2.1 Data of the weight loss from TGA of Mg-doped La2NiO4 (First order) 46
4.2.2 Calculation of Non-stoichiometric Oxygen vacancy in the Mg-doped La2NiO4 47
4.4 Morphologies examined by Scanning Electron Microscope (SEM) 48
4.4.1 Characterization of the Morphology 48
4.4.2 Compositional analysis by Energy-dispersive spectroscopy mapping 51
4.5 Analysis of Electrical Conductivity 54
4.5.1 Electrical conductivity 54
4.5.2 Determination of Energy activation 55
4.6 Thermal Expansion Coefficient (TEC) of the Cathode Materials 56
4.7 Electrochemical Behavior Properties 57
4.7.1 DC polarization curve of single cell 57
4.7.2 Study by Electrochemical Impedance Spectroscopy (EIS) 62
Chapter 5 Discussion 67
5.1 Phase 1: Magnesium-doping in RP structure La2NiO4 67
5.2 Phase 2: Magnesium-doping in higher-order (n=1,2 and 3) of Lan+1NinO3n+1 68
5.3 Phase 3: Application in different SOFC cell configuration 71
5.4 Role of Micro-doped Magnesium in La2NiO4 73
Chapter 6 Conclusion and Outlook 75
6.1 Conclusion 75
6.2 Outlook 75
References xii
Appendix A: Tables of Experimental Data for Different Compound Used in this Work xvi
Appendix B: Simulated Data of the Electrochemical Impedance Spectroscopy (EIS) Fitted by Z-View Software xx
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