质子导体固体氧化物燃料电池复合阴极材料的制备与性能研究

发布时间：2018-03-27 05:02

  本文选题：质子导体　切入点：固体氧化物燃料电池　出处：《郑州大学》2017年硕士论文

【摘要】：能源和环境问题是当今社会发展所面临的主要问题,开发清洁环保的新能源成为人类实现可持续发展的必然选择。固体氧化物燃料电池(SOFC)作为一种直接将化学能转化为电能的装置,具有能量转化效率高、环境污染小和燃料适应性强等优点,成为研究热点之一。传统SOFC对工作温度要求较高,高的工作温度必将带来电极的烧结退化、界面的扩散反应以及难以封接等问题,因此降低电池操作温度已成为SOFC的主要研究方向。其中质子导体固体氧化物燃料电池(H-SOFC)具有较低的活化能,是实现SOFC中低温化的一个重要途径。本论文主要研究了不同电解质H-SOFC的电化学性能及不同组分阴极对电池电化学性能的影响。第一章,简述了SOFC的研究背景、结构类型、工作原理、关键材料以及质子导体的传导机制,并介绍了H-SOFC的发展现状和本论文的研究思路。第二章,简单介绍了实验所需药品与仪器,以及实验用到的表征方法与测试手段。第三章,制备了NiO-BaZr0.1Ce0.7Y0.2O3-δ(NiO-BZCY)/BaZr0.1Ce0.7Y0.2O3-δ(BZCY)/Ba0.5Sr0.5FeO3-δ(BSF)-Ce0.8Sm0.2O2-δ(SDC)单电池。采用柠檬酸盐燃烧法制备了单电池所需初始粉体。通过XRD对粉体相结构进行分析,得出初始粉体均成相较好,无明显杂相产生。单电池的功率测试表明,750℃下单电池的最大功率密度(MPD)为413.5 mW·cm-2,开路电压(OCV)为0.926 V。对单电池电化学阻抗谱的测试可以看出,750℃下单电池具有较小的极化电阻(Rp),阻值为0.301Ωcm2。通过扫描电镜观察单电池断面的微结构,进一步研究了微结构对电池性能的影响。第四章,制备了BSF-SDC(7:3,5:5,3:7 wt%)三种复合阴极材料,主要研究了在以Ba Zr0.1Ce0.7Y0.1Yb0.1O3-δ(BZCYYb)为电解质的基础上,不同阴极组分对电池性能的影响。XRD检测发现BZCYYb粉体呈现出单一的钙钛矿结构,阳极衬底中的电解质BZCYYb和NiO之间相结构独立存在。煅烧后的BSF-SDC复合粉体中BSF和SDC呈分离相,BSF具有立方钙钛矿的峰,SDC具有萤石结构,说明BSF和SDC之间的化学相容性良好,可以用做复合阴极材料。热膨胀性能分析表明三组阴极材料200-750℃的热膨胀系数依次为15.8×10-6 K-1,14.5×10-6 K-1和13.6×10-6 K-1,相对于钴酸盐基阴极的热膨胀系数较低,更适合用于BZCYYb电解质。通过对三种阴极单电池的电化学测试得出,750℃下BSF-SDC55和BSF-SDC37的最大功率密度为449和388 mW·cm-2,极化电阻为0.021和0.291Ωcm2。相对而言BSF-SDC73单电池具有较好的电化学性能,其750℃下的最大功率密度和最低极化电阻分别为531 m W·cm-2和0.019Ωcm2。结果表明BSF-SDC73复合阴极可能是一种很有前途的H-SOFC阴极材料,BZCYYb电解质材料相较于BZCY表现出更优异的电化学性能。第五章,对本论文所有工作进行了总结,对质子导体固体氧化物燃料电池的发展及以后的工作进行了展望。
[Abstract]:Energy and the environment are the main problems facing the development of today's society. The development of clean and environmentally friendly new energy sources has become an inevitable choice for human to achieve sustainable development. Solid oxide fuel cells (SOFCCs), as a device that directly converts chemical energy into electric energy, has high energy conversion efficiency. The advantages of low environmental pollution and strong fuel adaptability have become one of the research hotspots. Traditional SOFC requires high working temperature, which will lead to the degradation of electrode sintering, diffusion reaction of interface and difficulty in sealing. Therefore, lowering the operating temperature of the cell has become the main research direction of SOFC, in which the proton conductor solid oxide fuel cell (SOFC) has a low activation energy. In this paper, the electrochemical performance of H-SOFC with different electrolytes and the effect of different cathode components on the electrochemical performance of SOFC are studied. In chapter 1, the research background and structure types of SOFC are briefly described. The working principle, the key materials and the conduction mechanism of proton conductors are introduced. The development of H-SOFC and the research ideas of this paper are also introduced. In chapter 3, NiO-BaZr0.1Ce0.7Y0.2O3- 未 -NiO-BZCYP / BaZr0.1Ce0.7Y0.2O3- 未 BZCY-Ba0.5Sr0.5FeO3- 未 BZCY-Ba0.5Sr0.5FeO3- 未 BSF-0.8Sm0.2O2- 未 single cell was prepared by citrate combustion method, and the phase structure of the powder was analyzed by XRD. The maximum power density (MPD) of single cell was 413.5 MW cm-2 and the open circuit voltage was 0.926 V. the electrochemical impedance spectrum of single cell could be seen to be smaller than that of the ordered cell at 750 鈩，

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