摘要:在SOFC不同的电解质研究中,其应用最为成功、研究时间最长的是掺杂了萤石结构的Gd2O3基电解质材料,其中应用最为普遍的是YSZ(Y2O3稳定的ZrO2),YSZ具有很好的电解质特性,如:它的抗氧化还原性很好、稳定性强,而且材料储量充足,价格低等。它在高温的气氛条件下,仍然保持着良好的导电性能以及优良的较强的化学稳定性。研究表明,作为BaCeO3基的质子导体燃料电池拥有较高的电导率,其中Gd3+掺杂的BaCeO3是近些年报道最频繁、最热门的质子传导材料,成为固体氧化物燃料电池(SOFC)电解质的研究热点。在本实验中,除了在原料铈酸钡中掺杂Gd3+之外,同时也在铈酸钡中加入In3+,原因是In3+可以大幅提高BaCeO3材料的化学稳定性以及其烧结活性,并在其中加入4%-CuO以降低其反应所需的烧结温度。
该篇论文主要可分为三个章节,第一章是对于质子导电的固体氧化物燃料电池的结构以及工作原理进行介绍。对质子导电的机理进行简单介绍,关于质子导电的固体氧化物燃料电池发展存在的问题以及发展前景有一个了解。分析提出论文的研究目的以及意义。第二章是对实验中的研究方法和实验参数有一个大致的介绍,对于实验中的实验流程有一个大体的了解,熟悉实验中的实验设备以及实验材料,对于实验中的XRD、SEM、DTA-TG等实验方法有一定的了解,熟悉它们的实验原理以及作用。第三章是利用固相反应法合成BaCe0.7In0.2Gd0.1O3-δ样品,把样品处于不同的反应条件下进行反应,得到不同反应条件后的产物。并对材料进行XRD、SEM、DTA-TG的表征。最后,通过研究分析样品在CO2,H2O中的反应,对处理过的样品进行XRD、SEM物相表征,分析反应程度和反应产物。通过DTA-TG研究化学稳定性,研究化学反应气氛、反应温度区间以及反应产物。经过实验表明,在ABO3型电解质样品中A与B位掺杂了Gd3+与In3+元素有利于它在二氧化碳与水蒸气的气氛条件下提高化学稳定性。电解质样品BaCe0.7In0.2Gd0.1O3-δ在二氧化碳与水蒸气的气氛条件下仍然表现出单相钙钛矿结构,具有稳定的化学稳定性。掺杂了Gd3+以及In3+等元素后,在H2O和CO2的气氛条件下,电解质样品不能够长时间地暴露于水蒸气环境下,会生成Ba(OH)2,而掺杂了Gd3+与In3+元素后,在CO2气氛条件下,表现出了很好的化学稳定性。
关键词:质子导体;化学稳定性;铈酸钡基电解质;固体氧化物燃料电池;
Abstract:SOFC is the most widely studied, and its application is the most successful for the doping of fluorite-based zirconia-based electrolyte materials. The most widely used is YSZ (Y2O3 stable ZrO2), YSZ antioxidant Restore stability is good, rich in materials and low prices. In high temperature conditions with high enough oxygen ion conductivity and good chemical stability and mechanical properties. Studies have shown that BaCeO3-based proton conductor fuel cells have a high conductivity, in which Gd3 + doped BaCeO3 is the most frequent and popular proton conducting material reported in recent years and has become a solid oxide fuel cell (SOFC) electrolyte Research hot-spot. In this experiment, In3 + was added to barium cerium oxide in addition to the addition of Gd3 + in the raw material cerium oxalate, because In3 + could greatly improve the chemical stability and sintering activity of BaCeO3 material and add 4 % -CuO to reduce the sintering temperature required for its reaction.
The paper is pided into three chapters, the first chapter is for the proton conductive solid oxide fuel cell structure and working principle are introduced. The mechanism of proton conduction is briefly described, and there is an understanding of the problems and prospects of the development of proton-conducting solid oxide fuel cells. Analyzes the purpose and significance of the paper. In the second chapter, we have a general introduction to the research methods and experimental parameters in the experiment. We have a general understanding of the experimental process in the experiment. We are familiar with the experimental equipment and experimental materials. For the experiment, XRD, SEM, DTA -TG and other experimental methods have a certain understanding, familiar with their experimental principles and role. In the third chapter, the samples of BaCe0.7In0.2Gd0.1O3-δ were synthesized by solid phase reaction, and the samples were reacted under different reaction conditions to obtain the products after different reaction conditions. And characterized by XRD, SEM and DTA-TG. Finally, the reaction of samples in CO2 and H2O was studied by XRD and SEM. The reaction degree and reaction product were analyzed. The chemical stability was studied by DTA-TG, the chemical reaction atmosphere, the reaction temperature interval and the reaction product were studied. Experiments show that the addition of Gd3 + and In3 + elements to A and B in ABO3 electrolyte samples is beneficial to improve the chemical stability under the atmosphere of carbon dioxide and water vapor. The electrolyte samples BaCe0.7In0.2Gd0.1O3 still show single-phase perovskite structure under the atmosphere of carbon dioxide and water vapor, and have stable chemical stability. After absorbing the elements such as Gd3 + and In3 +, the electrolyte samples can not be exposed to water vapor for a long time under the atmosphere of H2O and CO2, and Ba (OH) 2 is formed, and after Gd3+ and In3 + elements are doped , In the CO2 atmosphere conditions, showing a very good chemical stability.