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https://ptsldigital.ukm.my/jspui/handle/123456789/475850Full metadata record
| DC Field | Value | Language |
|---|---|---|
| dc.contributor.advisor | Andanastuti Muchtar, Prof. Dr. | - |
| dc.contributor.author | Muhammed Ali S. A (P59372) | - |
| dc.date.accessioned | 2023-10-05T06:42:25Z | - |
| dc.date.available | 2023-10-05T06:42:25Z | - |
| dc.date.issued | 2015-09-11 | - |
| dc.identifier.other | ukmvital:121375 | - |
| dc.identifier.uri | https://ptsldigital.ukm.my/jspui/handle/123456789/475850 | - |
| dc.description | A solid oxide fuel cell (SOFC) is a promising technology with unique characteristics that can be used to generate electricity by combining hydrogen and oxidant as fuel. SOFC operates at very high temperatures (800 °C to 1000 °C), which is one of the major limiting factors in the advancement of SOFC applications. Therefore, the operating temperature must be reduced to anticipate SOFC in the commercial market by developing suitable material with similar properties performing at low temperature. Low operation temperatures, however, require increased electrolyte ionic conductivity and enhanced electrode reaction activity. Therefore, this study is concerned with two distinct aspects of SOFC composite electrolyte and cathode material development. The goal of the present study is to develop a composite electrolyte of samarium-doped ceria-carbonate (SDCC) and to improve the material properties of La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) cathode for use in low-temperature SOFC (LT-SOFC). The SDCC composite electrolyte was prepared with the following composition: 80 wt% samarium-doped ceria (SDC) with 20 wt% (Li/Na)2CO3 via a solid state reaction method. The SDCC composite pellets were sintered at various temperatures ranging from 500 °C to 650 °C. In order to improve the physical and sintering properties of LSCF cathode powder, a new procedure was used to obtain nano-sized ceramic powder at a low calcination temperature in the absences of ammonia solution. To compare, the cathode powder was prepared by two different methods, namely (1) the combined ethylenediaminetetraacetic acid–citric acid combustion, and (2) rotary evaporation method. The phase structure, microstructure and specific surface area of the prepared powders were investigated using an X-ray diffractometer (XRD), field emission scanning electron microscopy (FESEM) and Brunauer-Emmett-Teller technique, respectively. Atomic force microscopy (AFM) was used to investigate the surface roughness of the SDCC composite electrolyte pellets. Electrochemical measurements were investigated from 350 °C to 550 °C using an impedance spectroscopy for the SDCC composite pellets. XRD analysis confirmed the stability of the prepared SDCC composite electrolyte powder, with no new peaks or new compound was formed. The specific surface area of the pure SDC powder decreased from 8.85 m2 g -1 to 4.24 m2 g -1 after incorporation of carbonate phase onto the SDC phase due to increase in the particle size. The porosity, grain size, surface roughness, phase continuity, and electrical properties of SDCC composite electrolyte are closely associated with sintering temperature. A fully dense SDCC composite electrolyte with 3% porosity for the pellet sintered at 550 °C and also exhibited a maximum ionic conductivity of 0.040 Scm-1 and low activation energy of 0.57 eV at an operating temperature of 550 °C. In addition, 550 °C was found to be the minimum sintering temperature to achieve a moderate particle size and low surface roughness. Therefore, the preferred sintering temperature for the SDCC electrolyte composite pellet is 550 °C. The study on the different preparation method of LSCF cathode powder indicates that the phase formation, particle size, powder morphology, and sinterability are strongly dependent on the nature of the synthesis methods. The combustion method produced pure LSCF powder as observed from XRD after calcining at 800 °C. A homogeneous LSCF powder with high surface area of 8.15 m2 g -1 and <30 nm particle size were obtained from the combustion method as compared with that produced by the rotary evaporation method. Therefore, an optimisation of cathode preparation and sintering condition of the composite electrolyte is important in the development of LT-SOFC.,“Certification of Master’s / Doctoral Thesis” is not available,Sarjana (Sains) | - |
| dc.language.iso | eng | - |
| dc.publisher | UKM, Bangi | - |
| dc.relation | Fuel Cell Institute / Institut Sel Fuel | - |
| dc.rights | UKM | - |
| dc.subject | Universiti Kebangsaan Malaysia -- Dissertations | - |
| dc.subject | Dissertations, Academic -- Malaysia | - |
| dc.subject | Solid oxide fuel cells | - |
| dc.subject | Fuel cells -- Materials | - |
| dc.subject | Composite materials | - |
| dc.subject | Hydrogen as fuel. | - |
| dc.title | Development of doped ceria-carbonate-based composite electrolyte and lanthanum strontium-based cathode for solid oxide fuel cells | - |
| dc.type | Theses | - |
| dc.format.pages | 110 | - |
| dc.identifier.callno | TK2933.S65M843 2013 3 tesis | - |
| Appears in Collections: | Fuel Cell Institute / Institut Sel Fuel | |
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