流延—叠层法制备平板型中温固体氧化物燃料电池的研究

发布时间：2018-06-23 11:26

本文选题：固体氧化物燃料电池 + 氧化衫掺杂二氧化铈　；参考：《武汉理工大学》2010年博士论文

【摘要】： 固体氧化物燃料电池(SOFC)因其零排放、高效率、燃料适应性广而成为一种举世公认的绿色能源,得到了世界范围内的广泛关注。但在走向实用化和商业化进程中,还有一些问题没有解决。其中一个主要问题是SOFC的工作温度过高,从而带来种种技术和材料困难。解决的主要措施是减小工作温度下固体电解质隔膜的电阻、提高电极的催化活性及机械强度。研究中温下具有高离子电导率的固体电解质材料,以及采用匹配性好和机械性能优良的阳极支撑的薄膜电解质,是近年来国际上的热点。本论文工作采用环保的醋酸盐为原料,以喷雾热分解技术制备氧化衫掺杂二氧化铈(SDC)粉末,研究实验配方及喷雾热分解工艺对SDC粉末性能的影响,并采用差热-热重分析及热力学计算研究了SDC的形成机制。系统研究了水基流延SDC浆料的制备、分散剂及其分散机理、流变学特性、浆料干燥及成膜机理,结果表明：当固相含量大于50wt.%时浆料显示出较明显的假塑性行为。三乙醇胺的分散机理主要为静电稳定机理。以20-25℃干燥16-24后,得到了表面平整光滑、显微结构均匀、强度和柔韧性高的SDC、NiO-SDC和NiO-YSZ：氧化钇稳定氧化锆)单膜生坯,生坯厚度与刮刀第2道刀口间隙的高度之间满足1/2.5-1/3的关系。研究了不同的脱脂和烧结制度对流延成型的SDC电解质性能的影响,结果表明：高温烧成后SDC的相结构没有发生改变,而晶粒尺寸增大。1400℃烧结2小时后得到了相对密度为97%的SDC电解质。烧结过程的动力学模型指出升高温度、细化粉末粒径可以促进烧结过程的进行。SDC电解质的离子电导率表现出Arrhenius行为。1300℃,1400℃和1500℃烧结2小时的SDC电解质的电导活化能分别为1.24 eV,0.90 eV和1.08 eV。1400℃烧结2小时的SDC在600℃时得到最大的离子电导率为9.5×10-3S·cm-1。系统研究了电解质厚度、叠层层数、叠层温度、叠层压力、共烧制度等因素对叠层法制备NiO-SDC和NiO-YSZ阳极,以及NiO-SDC阳极或NiO-YSZ阳极支撑的SDC薄膜电解质性能的影响。结果表明：在较低的温度和压力下制备出了平整无裂纹的叠层片。经1400℃共烧2h后,NiO-YSZ阳极达到了较高的机械性能并达到实用要求。采用叠层法成功制备出了直径为25mm,厚度为1.2mm的NiO-YSZ阳极支撑SDC薄膜电解质半电池。从理论上推导了单电池电动势与温度的关系及电流与氢气用量间的关系,并首次提出了氢气用量的阈值。研究了温度和氢气用量对单电池Ni-YSZ//SDC//LSCF-SDC电学性能的影响。结果表明：单电池于500℃,600℃,700℃,800℃时的最大功率密度分别为26.60 mW/cm2,42.30 mW/cm2,66.78 mW/cm2,93.03 mW/cm2,开路电压分别为0.978V,0.921V,0.861V,0.803V。各个温度下单电池的浓差极化较大,较低温时欧姆极化较大。单电池中Ni-YSZ阳极和SDC电解质界面间发生反应形成了低电导率的中间层。在未达到氢气用量阈值之前,单电池产生的电流I和其氢气用量v之间满足v=1.25×10-71I的定量关系：阈值之后,电流不随氢气用量的增大而增大。本文最后对流延-叠层法制备阳极支撑平板型中温固体氧化物燃料电池的发展方向进行了展望,指出采用双层流延制备Ni-SDC//SDC//LSCF-SDC单电池,从而得到电极与电解质间无界面反应、匹配性好的单电池是进一步提高其性能的关键。
[Abstract]:Solid oxide fuel cell (SOFC) has become a worldwide recognized green energy source because of its zero emission, high efficiency and wide adaptability to fuel. However, there are some problems that have not been solved in the process of becoming practical and commercialized. One of the main problems is that the working temperature of SOFC is too high. The main measures to be solved are to reduce the resistance of the solid electrolyte diaphragm at working temperature and to improve the catalytic activity and mechanical strength of the electrode. The study of the solid electrolyte materials with high ionic conductivity at middle temperature and the film electrolytes with good matching and excellent mechanical properties are the recent years. Come to the hot spot at the international level.
In this paper, two cerium oxide (SDC) powder was prepared by the spray thermal decomposition technique with the green acetate as the raw material. The effect of the experimental formula and the spray thermal decomposition process on the properties of SDC powder was studied. The formation mechanism of SDC was studied by differential thermal gravimetric analysis and thermodynamic calculation.
The preparation of water based SDC slurry, dispersant and its dispersing mechanism, rheological properties, slurry drying and film forming mechanism are studied. The results show that the slurry shows a more obvious pseudoplastic behavior when the solid content is greater than 50wt.%. The dispersion mechanism of triethanolamine is mainly the mechanism of static electricity stability. After drying at 20-25 degrees centigrade for 16-24, the table is obtained. The surface of the SDC, NiO-SDC and NiO-YSZ: yttrium stabilized zirconia and the height of the second blade gap of the scraper meet the relationship between the height of the blade and the height of the blade gap between the blade and the blade.
The effect of different degreasing and sintering systems on the performance of SDC electrolyte was studied. The results showed that the phase structure of SDC was not changed after high temperature sintering, and the relative density of SDC electrolyte was obtained after 2 hours of grain size increasing at.1400 C. The kinetic model of the sintering process pointed out the increase of temperature and refining the powder. The ionic conductivity of the sintering process can be promoted by the particle size of the.SDC electrolyte, which shows the Arrhenius behavior at.1300 C. The conductance activation energy of the SDC electrolyte at 1400 and 1500 C for 2 hours is 1.24 eV, 0.90 eV and 1.08 eV.1400 C for 2 hours at 600 degrees C, and the maximum ionic conductivity is 9.5 x 10-3S. Cm-1..
The effects of electrolyte thickness, layer number, layer temperature, stacking pressure, CO firing system on the preparation of NiO-SDC and NiO-YSZ anodes by stacking method and the performance of SDC film electrolyte supported by NiO-SDC anode or NiO-YSZ anode were investigated. The results showed that the layer without crack was prepared under the lower temperature and pressure. After a co firing of 2H at 1400 C, the NiO-YSZ anode achieved high mechanical properties and achieved practical requirements. The NiO-YSZ anode supported SDC film electrolyte half battery with a diameter of 25mm and a thickness of 1.2mm was successfully prepared by stacking method.
The relationship between the electromotive force and the temperature of the single cell and the relation between the current and the amount of hydrogen is derived theoretically. The threshold of the amount of hydrogen is first proposed. The effects of the temperature and hydrogen amount on the electrical properties of the single cell Ni-YSZ//SDC//LSCF-SDC are studied. The results show that the maximum power density of the single cell at 500, 600, 700, and 800. The 26.60 mW/cm2,42.30 mW/cm2,66.78 mW/cm2,93.03 mW/cm2, respectively, the open circuit voltage is 0.978V, 0.921V, 0.861V, and 0.803V., the concentration polarization of the single cell is larger and the ohm polarization is larger at the lower temperature. The middle layer between the Ni-YSZ anode and the SDC electrolyte interface should be formed in the single battery. Before the dosage threshold, the quantitative relationship between the current I produced by a single cell and the amount of hydrogen content of V satisfies the quantitative relationship of v=1.25 x 10-71I: after the threshold, the current does not increase with the increase of the amount of hydrogen.
At the end of this paper, the development direction of the plate type medium temperature solid oxide fuel cell (solid oxide fuel cell) for the anode supported plate by the laminating method is prospected. It is pointed out that the double layer casting is used to prepare the Ni-SDC//SDC//LSCF-SDC single cell, so that there is no interfacial reaction between the electrode and the electrolyte, and the single cell with good matching is the key to further improve its performance.
【学位授予单位】：武汉理工大学
【学位级别】：博士
【学位授予年份】：2010
【分类号】：TM911.4

【相似文献】