中温固体氧化物燃料电池材料的性质与性能探究

发布时间：2018-03-21 00:06

本文选题：中温固体氧化物燃料电池　切入点：非氢燃料　出处：《天津大学》2016年博士论文　论文类型：学位论文

【摘要】：固体氧化物燃料电池(SOFC)能够经电化学途径直接将燃料的化学能高效环保地转化为电能。其较高的工作温度(800 oC以上)虽能带来许多优势,但又会引发诸多问题。因此在400-800 oC的中低温工作成为了其主要发展趋势。对电池材料结构及制备工艺进行优化开发,实现非氢燃料的直接利用,则成为了中温SOFC发展应用的关键。本文对此从多个角度做出探索与尝试,取得以下进展:(1)第二章制备的Sr2Fe1.5Mo0.5O6(SFM)钙钛矿材料,作为中温SOFC阳极表现出良好的活化醇类燃料的性能和抗积碳能力。SFM材料采用柠檬酸-EDTA溶胶凝胶法制备,在氧化和还原气氛中均能稳定存在。通过丝网印刷法制备的电解质支撑SFM|La0.8Sr0.2Ga0.83Mg0.17O3|Ba0.5Sr0.5Co0.8Fe0.2O3全钙钛矿单电池片,在使用甲醇和乙醇作为燃料进行放电测试时,可以分别获得800 oC时431和340 mW cm-2的输出性能,并且在SFM阳极上并没有观察到有积碳生成。(2)第三章采用SFM与Ce0.8Sm0.2O2-Na2CO3的复合材料成功制备了新型的单部件燃料电池(SLFC),揭示其离子电子混合电导的比例与电池性能间的关系。复合材料中SFM的含量对SLFC电池影响性能显著,含30 wt.%SFM的SLFC可以在750 oC获得1.05 V的开路电压和360 mW cm-2的最高功率输出,与常规的三部件电池相匹及。通过对SLFC开路电压影响因素的讨论,进一步揭示了SLFC中离子电子电导比例与其电池性能间的关系。(3)第四章考察了Li Ni0.5Mn1.5O4(LNM)尖晶石作为中温SOFC阴极的材料性质和电极性能,阐述了电化学性能与其快速的吸放氧能力间的关系。LNM材料显示出了良好的热稳定性和与YSZ电解质的兼容性。在800 oC的空气中材料电导约为5 S cm-1。材料中高含量的Mn4+使LNM有着更好的化学及电化学催化活性。使得LNM阴极在700 oC以上表现出比传统La0.8Sr0.2MnO3更好的电极性能,以及热重分析表现出的更强的吸放氧能力。(4)第五章提出了一种新型的四电极交流阻抗测试法用于考察中温SOFC电解质,并测量分析了常规的Gd0.1Ce0.9O2(GDC)材料在四电极及两电极连接方法下的交流阻抗及直流电阻。测试结果、交流阻抗拟合及电阻来源验证实验表明,四电极交流阻抗法可以获得样品阻抗并排除电极上界面过程的影响,因此可以更好地理解材料中的界面过程。此方法还可以进一步被用来考察更加复杂的掺杂氧化铈-碳酸盐复合电解质系统,相关工作整理进行中。
[Abstract]:Solid oxide fuel cell (SOFC) can directly convert the chemical energy of fuel into electric energy by electrochemical route. Its higher working temperature is more than 800oC, although it can bring many advantages. However, it will lead to many problems. Therefore, the low and medium temperature work in 400-800oC has become the main development trend. The structure of battery materials and the preparation process are optimized to realize the direct utilization of non-hydrogen fuel. It has become the key to the development and application of medium-temperature SOFC. In this paper, we have explored and tried from many angles, and made the following progress: 1) the Sr2Fe1.5Mo0.5O6SFM) perovskite material prepared in Chapter 2. As a moderate temperature SOFC anode, it shows good properties of activated alcohols fuel and its ability to resist carbon deposition. It was prepared by citric acid-EDTA sol-gel method. SFM La0.8Sr0.2Ga0.83Mg0.17O3 Ba0.5Sr0.5Co0.8Fe0.2O3 full perovskite monolithic cells were supported by electrolytes prepared by screen printing. When methanol and ethanol were used as fuel for discharge test, The output performance of 431 and 340 MW cm-2 can be obtained at 800oC, respectively. No carbon deposition was observed on the anode of SFM.) in chapter 3, a novel single-component fuel cell was successfully fabricated by using composite materials of SFM and Ce0.8Sm0.2O2-Na2CO3 to reveal the relationship between the ratio of ion and electron mixing conductance and the performance of the cell. The content of SFM in composite material has a significant effect on the performance of SLFC battery. The SLFC with 30 wt.%SFM can obtain an open circuit voltage of 1.05 V and a maximum power output of 360MW cm-2 at 750oC, which is comparable to the conventional three-component battery. The factors affecting the open circuit voltage of SLFC are discussed. The relationship between ion electron conductance ratio and battery performance in SLFC was further revealed. Chapter 4th investigated the material properties and electrode properties of Li Ni 0.5 mn 1.5 O 4 LNM) spinel as intermediate temperature SOFC cathode. The relationship between electrochemical performance and its rapid oxygen absorption and discharge ability. LNM material shows good thermal stability and compatibility with YSZ electrolyte. The conductivity of the material is about 5S cm-1 in 800oC air. Mn4 makes LNM have better chemical and electrochemical catalytic activity, and makes LNM cathode show better electrode performance than traditional La0.8Sr0.2MnO3 at 700oC. In chapter 5th, a new four-electrode AC impedance method is proposed for investigating SOFC electrolytes at moderate temperature. The AC impedance and DC resistance of conventional Gd0.1Ce0.9O2GDC-based materials under four-electrode and two-electrode connection methods are measured and analyzed. The results of measurement, AC impedance fitting and resistance source verification experiments show that, The four-electrode AC impedance method can obtain the impedance of the sample and exclude the influence of the interface process on the electrode. This method can be further used to investigate the complex doped cerium oxide carbonate composite electrolyte system and the related work is in progress.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TM911.4

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