【作者】 王景锋；

【导师】 吕喆；

【作者基本信息】 哈尔滨工业大学 ， 凝聚态物理， 2008， 硕士

【摘要】 单气室固体氧化物燃料电池(SC-SOFC)是一种新型结构燃料电池,这种电池仅在一个气室中运行,因而不同于传统的、由被致密的电解质隔开的两个气室构成的双气室结构的燃料电池。SC-SOFC的运行原理基于阳极和阴极对燃料和氧气不同的选择催化性,要求阴极对O2的还原催化活性较高,要求阳极对燃料催化活性较高,这种催化差异使两电极之间产生了电动势。SC-SOFC具有如下优点:阴阳极之间无需密封;多孔电解质也可以使用;可以比较容易地实现小规模的电池组设计。本文工作主要包括对影响电解质支撑型SC-SOFC单电池性能的因素进行分析,重点了研究电池的结构类型、温度、气体配比、电极选配等这些关键材料和技术参数对SC-SOFC性能的影响规律,进而对电解质支撑型SC-SOFC电池组进行了设计和初步的实验探索,还专门针对电解质支撑型SC-SOFC电池组的特点,提出了中间带隔离层的单片电池组结构设计。本论文的研究结果表明,对于电解质支撑型的SC-SOFC,阳极的厚度严重影响其单电池性能,因为传统的电解质支撑型电池所用的阳极涂层无法使其得到稳定的开路电压输出,阳极必须达到一定的厚度。在成功制备了电解质支撑型SC-SOFC的基础上,比较系统地研究了环境温度、混合气体组分等因素对电池开路电压(OCV)和功率密度的影响。发现阴极/阳极对侧布局的单电池在700°C、CH4/O2比例等于2:1时,电池性能最好,此时电池的OCV值达到1.01V ,接近理论值,对应的最高输出功率密度为151.4 mW/cm2 ,最大放电电流密度为624.6mA/cm2。用按照Sm0.2Ce0.8O1.9(SDC)计量比配制的Sm(NO3)3和Ce(NO3)3混合溶液对电池的阴极进行浸渍后,电池的性能能够得到明显的改善。对电解质支撑型SC-SOFC,进行了三种结构电池组的实验。在700℃、CH4/O2比例等于2:1时,A型结构的两电池组和三电池组的OCV值分别为1.66、2.76V,对应最高功率密度分别为61.5mW/cm2、96.82mW/cm2,B型结构的两电池组OCV值1.62V,对应的最高功率密度为9.35mW/cm2。开发出带有中间隔离层的新型三明治结构电解质片,研究了它对不同电极布局的单电池内阻的影响规律,发现隔离层可以有效地提高上下电解质层上电极之间的电阻。通过选择催化性强的电极材料和优化工作条件,电池组的性能会有更近一步的提高。更多还原

【Abstract】 Single-chamber solid oxide fuel cell (SC-SOFC) is a novel type fuel cell which can operate in only one gas chamber,while conventional fuel cell consist of two gas chambers partitioned by gastight electrolyte. Working principle of SC-SOFC is based on difference of two electrodes’electrocatalytic activity for fuel and air, and anode has a higher electrocatalytic activity for the oxidation of the fuel, whereas cathode has a higher electrocatalytic activity for eduction of oxygen. Thus it results in an electromotive force (EMF) between the two electrodes. SC-SOFC have some advantages over conventional SOFC: Tealing between anode and cathode is unnecessary; porous electrolyte can be used; The design of small scale stacks is easy. This paper mainly includes exploring which factor has an influence on electrolyte supported SC-SOFC performance, and we placed emphsis on researching how cell type, temperature, gas flow ratio as well as electrode choice affect SC-SOFC performance and further designed and explored stacks. in the end we designed an stack structure using electrolyte which has an separated layer among it especiallly for the feature of electrolyte-supported SC-SOFC.Research result in this paper showed that thickness of anode for electrolyte supported SC-SOFC affected its performance.Because anode layer for conventional electrolyte supported SC-SOFC can’t make it reach a steady open circuit potentional(OCV), it was necessary to make cell anode more thicker. We systematically discussed how temperature and composition of mixed gas affected cell electrochemical properties , and founded cell Performance was best when ratio of CH4 to O2 is 2 at 700℃,OCV of cell reached 1.01V at 700℃, which approached theory voltage value. Maximum power density of cell reached 151.4 mW/cm2 and maximum discharge current density of cell reached 624.6mA/cm2。After cathode of cell was impregnated by the mixed solution of Sm(NO3)3 and Ce(NO3)3 prepared according to the computation ratio of Sm0.2Ce0.8O1.9(SDC), the properties of cell could be improved obviously.The investigation on SC-SOFC stacks involved three sorts of structure stacks. When the ratio of CH4 to O2 is equal to 2 at 700°C, OCV of A-type stack with two and three single cells was 1.66、2.76V, correspondingly the maximum power density was 61.5、96.82mW/cm2, respectively. In the same condition as above, OCV of B-type stack with two single cells was 1.62V,and the maximum power density was 9.35mW/cm2. We developed an one called sandwich structure electrolyte and researched how it affected inter resistence of single cell when cell electrodes arrangement was different, and we founded separated layer could effectively improve impedance between two electrode which are located on the opposite sides of electrolyte. We could improve properties of cell by seeking electrode material with good selective catalysis and optimizing work conditions.更多还原