Fabrication and property optimization of micro-SOFC with thin film electrolyte

다국어 초록 (Multilingual Abstract)

Solid oxide fuel cell (SOFC) technology has drawn much attention for the next generation power sources of several kilowatt levels such as residential power generation because an SOFC has the highest efficiency among fuel cell types. Recently, increasing interest has been paid to develop micro-SOFCs for novel portable and mobile power sources because the merits of SOFCs, such as high power and energy density, system efficiency and fuel flexibility, are also very intriguing properties for portable power sources.
To realize micro-SOFCs for portable applications, operating temperature decrease without performance compromise should be accomplished as well as size reduction because lowering the operating temperature is an important task for cutting down the burden in thermal management of an integrated power pack.
Hence, in this study, the performance of micro-SOFCs with thin film electrolytes and electrodes was investigated at a lower operating temperature regime (T ≤ 600°C). 2⨉2cm anode-supported unit cells with thin film components of a Ni-yttria-stabilized zirconia (YSZ) composite anode interlayer, a thin (1μm) YSZ electrolyte, and a lanthanum strontium cobalt (LSC) oxide cathode were fabricated by using pulsed laser deposition, and the performance of the cells was characterized at the temperature range of 350°C≤ T ≤600°C. Stable open-circuit voltage values above 1V were successfully obtained with thin film electrolyte cells, which implied that the 1μm-thick electrolyte was fairly dense and gastight. The thin film electrolyte cells exhibited a much more improved cell performance than a thick film(∼8μm YSZ) electrolyte cell at the low operating temperature regimes (350oC ∼ 550°C) and, in some cases, showed better power outputs than other thin film membrane micro-SOFCs.

목차 (Table of Contents)

• Contents
• Abstract.......................................................................................................................... I
• Contents...................................................................................................................... III List of Figures.............................................................................................................. V
• List of Tables.............................................................................................................. IX
• 1. Introduction............................................................................................................... 1
• 2. Literature Review...................................................................................................... 2
• 2.1. Solid Oxide Fuel Cell (SOFC)........................................................................... 2
• 2.2. Micro-SOFC with Thin Film Electrolyte........................................................... 4
• 2.3. Pulsed Laser Deposition (PLD).......................................................................... 7
• 3. Experimental........................................................................................................... 12
• 3.1. Thin Film Components Fabrication................................................................. 12
• 3.1.1. Electrolyte Thin Film................................................................................. 12
• 3.1.2. Cathode Thin Film..................................................................................... 12
• 3.1.3. Anode Thin Film........................................................................................ 13
• 3.2. Cell Fabrication................................................................................................ 14
• 3.3. Characterization................................................................................................ 15
• 4. Results and Discussion............................................................................................ 17
• 4.1. Physical Property of Thin Film Components................................................... 17
• 4.1.1. YSZ Thin Film........................................................................................... 17
• 4.1.2. LSC Thin Film……................................................................................... 17
• 4.1.3. NiO-, Ni-YSZ Thin Film........................................................................... 19
• 4.2. Cell Performance Optimization........................................................................ 24
• 4.2.1 Effect of Anode Interlayer.......................................................................... 24
• 4.2.2 Effect of GDC Buffer Layer....................................................................... 27
• 5. Conclusions............................................................................................................. 63
• References................................................................................................................... 65
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