DGIST Scholar: Highly Functional and Electrochemically Active Spinel Materials for Solid Oxide Fuel Cells

Department of Energy Science and Engineering Theses Ph.D.

Cited time in webofscience

Cited time in scopus

Highly Functional and Electrochemically Active Spinel Materials for Solid Oxide Fuel Cells

Title: Highly Functional and Electrochemically Active Spinel Materials for Solid Oxide Fuel Cells

Author(s): Imdadullah Thaheem

DGIST Authors: Thaheem, Imdadullah ; Lee, Chan-Woo ; Lee, Kang Taek

Advisor: 이강택

Co-Advisor(s): Chan-Woo Lee

Issued Date: 2020

Awarded Date: 2020-02

Type: Thesis

Description: Solid Oxide Fuel Cell, Solid Oxide Electrolysis, Spinel, Interconnect, Cathode, High Perfor-mance Oxidation Reduction Reaction, Oxygen Evolution Reaction.

Table Of Contents: Ⅰ. Introduction 1

ⅠI. Background 5
2.1 Solid Oxide Fuel Cells (SOFCs) 5
2.2 SOFC materials 7
2.2.1 Anode 7
2.2.2 Electrolyte 8
2.2.3 Cathode 9
2.2.4 Interconnect 11
2.3 Experimental Methods 14
2.3.1 Electrochemical Impedance Spectroscopy (EIS 14
2.3.2 Current-Voltage (C-V) measurements 15
2.4 Potential Losses of SOFC 15
2.4.1 Activation Polarization 15
2.4.2 Ohmic Polarization 16
2.4.3 Concentration Polarization 16

III. Structure and Electrical Properties of Mn1.4-0.5xCo1.4-0.5xCuxY0.1O4 (0.1 ≤ x ≤ 0.5) Spi-nel
Protective Coatings for Solid Oxide Fuel Cell Interconnect.
3.1 Introduction 22
3.2 Experimental Section 25
3.2.1 Material SynTheses 25
3.2.2 Preparation of the Coatings 25
3.2.3 Electrochemical measurement 26
3.2.4 Non-Isothermal Oxidation Test 26
3.2.5 Characterization 26
3.3 Results and Discussion 27
3.3.1 Powder Characterization 27
3.3.2 Electrochemical Performance 29
3.3.3 Oxidation Behavior 34
3.4 Conclusion 35

IV. High performing Mn1.3Co1.3Cu0.4O4 Spinel Based Composite Cathodes for
Intermediate Temperature Solid Oxide Fuel Cells.
4.1 Introduction 46
4.2 Experimental Section 48
4.2.1 Material Preparation 48
4.2.2 Cell Fabrication 48
4.2.3 Characterization 49
4.3 Results and Discussion 50
4.3.1 Powder Characterization 51
4.3.2 Ultraviolet-Visible Absorption 52
4.3.3 Electrochemical Properties 53
4.4 Conclusion 57

V. High Performing Nanostructured Mn1.3Co1.3Cu0.4O4 spinel Cathode for Intermediate
Temperature Solid Oxide Fuel Cells via an Infiltration Technique.
5.1 Introduction 68
5.2 Experimental Part 70
5.2.1 Material SynTheses 70
5.2.2 Cell Preparation 70
5.2.3 Characterization 71
5.3 Results and Discussion 72
5.3.1 Phase Structure and Chemical Compatibility 72
5.3.2 Wetting Contact Angle 72
5.3.3 Microstructure Analysis 73
5.3.4 Area Specific Resistance of MCCO infiltrated ScSZ cathode 73
5.3.5 Optimization by Precursor Solution Control 74
5.3.6 Optimization Microstructure and Electrochemical Properties 75
5.4 Conclusion 76

VI. High Performing Cobalt Iron Based Composite Cathode for Reversible Solid Oxide
Cells at Reduced Temperature.
6.1 Introduction 87
6.2 Experimental Section 89
6.2.1 Material SynTheses 89
6.2.2 Cell Fabrication 90
6.2.3 Characterization 91
6.3 Results and Discussion 91
6.3.1 Phase Analysis 92
6.3.2 Oxidation state of CFO Elements 92
6.3.3 Electrical Conductivity Analysis 93
6.3.4 Thermal Expansion Coefficient (TEC) Analysis 93
6.3.5 Chemical Compatibility 94
6.3.6 Electrical Properties 94
4.4 Conclusion 96

VII Summary 107

VIII. References 113