【作者】 李自强；

【导师】 罗天勇； 林彬；

【作者基本信息】 电子科技大学 ， 材料科学与工程， 2022， 硕士

【摘要】 固体氧化物电池（SOC）作为一种能源转化装置可以将燃料的化学能直接转化为电能,也可以通过将水和二氧化碳等电解还原成氢气和一氧化碳将电能转化为燃料的化学能,并不受卡诺循环限制,具有能量转化效率高、清洁无污染等优点。目前固体氧化物电池器件的进一步实用化受制于其电极材料的催化活性及其稳定性,本论文工作主要以对称型固体氧化物电池（SSOC）的电极材料作为研究对象,利用B位掺杂和原位脱溶技术对电极材料开展了改性研究。论文主要选取研究了以下电极材料:SrFeO_3-δ（SFO）;对SFO采用Mo进行B位掺杂的SrFe_0.9Mo_0.1O_3-δ（SFM）;对SFM微调化学计量比后进行原位脱溶表面修饰的SrFe_0.95Mo_0.1O_3-δ（SF95M）;对SFO微调化学计量比后进行原位脱溶表面修饰的SrFe_1.05O_3-δ（SF105O）。对基于以上四种电极材料的SSOC的研究发现:B位掺杂Mo元素可以有效提升SFO电极材料的催化性能,基于SFM的SSOC相比基于SFO的SSOC在800℃时的最大功率密度提升了约8%;原位脱溶表面修饰技术可以有效提高SFM电极材料的催化性能,基于SF95M的SSOC相比基于SFM的SSOC在800 ℃时的最大功率密度提升了约7.9%,经分析主要是因为Fe纳米颗粒脱溶于表面,增强了电极材料对于燃料气体的催化活性,并且分布均匀的纳米颗粒也提升了电极对于燃料气体的捕获能力,降低了电池的极化阻抗;基于SF105O电极的SSOC相比基于SF95M电极的SSOC在800 ℃,纯氢气氛围下的最大功率密度提升了约132%,经分析是因为对未进行B位掺杂的SF105O进行原位脱溶后,其结构会转变为非传统钙钛矿结构,Fe纳米颗粒脱溶于表面与基底的协同作用增强了电极对于燃料气体的催化活性。通过比较分析,论文认为B位掺杂和原位脱溶表面修饰都可以有效改善SFO的电极催化性能,其中基于原位脱溶后的SF105O电极的SSOC达到了最高的功率密度(800℃下1.3W.cm^-2),并实现了1200小时的稳定输出;进一步的电解水、二氧化碳以及水和二氧化碳共电解测试表明,该SSOC在800℃和1.6 V电压下,电解电流密度分别为1.778、0.943、1.265 A.cm^-2。因此基于SF105O的SSOC作为能量转换装置具有较高的实用推广价值,而非传统钙钛矿基底结构与原位脱溶修饰对电极催化性能的协同影响机理还有待于进一步研究。更多还原

【Abstract】 As an energy conversion device,a solid oxide cell（SOC）can directly convert the chemical energy of the fuel into electrical energy,or convert the electrical energy into the chemical energy of the fuel by electrolytic reduction of water and carbon dioxide into hydrogen and carbon monoxide.It is not limited by the Carnot cycle and has the advantages of high energy conversion efficiency,cleanliness and no pollution.The further practical application of solid oxide battery devices is currently limited by the catalytic activity and stability of their electrode materials.The work of this thesis mainly takes the electrode materials of symmetric solid oxide batteries（SSOC）as the research object,and uses the B site doping and in-situ exsolution technology to carry out the modification research of the electrode materials.The thesis mainly selects and studies the following electrode materials:SrFeO_3-δ（SFO）;SrFe_0.9Mo_0.1O_3-δ（SFM）which obtained by doping Mo at B site of SFO;in situ exsolution modification of SrFe_0.95Mo_0.1O_3-δ（SF95M）obtained by fine-tuning the stoichiometric ratio of SFM;in situ exsolution modification of SrFe_1.05O_3-δ（SF105O）obtained by fine-tuning the stoichiometric ratio of SFO.The research on SSOC based on the above four electrode materials found:doping Mo at the B site can effectively improve the catalytic performance of SFO electrode materials,and the maximum power density of SFM-based SSOC at 800 ℃ is increased by about 8%compared with SFO-based SSOC;the in-situ exsolution surface modification technology can effectively improve the catalytic performance of SFM electrode materials.Compared with the SFM-based SSOC,the maximum power density of the SF95M-based SSOC at 800 ℃ is increased by about 7.9%.According to the analysis,it is mainly because the Fe nanoparticles are exsolved on the surface,which enhances the catalytic activity of the electrode material for the fuel gas,and the uniformly distributed nanoparticles also improve the electrode ability to capture the fuel gas and reduce the polarization impedance of the cell;compared with the SSOC based on SF95M electrode at 800 o C,the SSOC based on SF105O electrode has a maximum power density increased by about 132%under pure hydrogen atmosphere.It is analyzed that the structure of SF105O without B site doping will be transformed into a non-traditional perovskite structure after in-situ desolubilization.The synergistic effect of Fe nanoparticles exsolution on the surface and the substrate enhanced the catalytic activity of the electrode for fuel gas.Through comparative analysis,the thesis believes that both B-site doping and in-situ exsolution surface modification can effectively improve the electrode catalytic performance of SFO,and the SSOC based on in-situ exsolution of SF105O electrode achieves the highest power density(at 800℃,1.3W.cm^-2)and 1200 hours of stable output;further electrolysis of water,carbon dioxide,and co-electrolysis of water and carbon dioxide showed that the SSOC had electrolytic current densities of 1.778,0.943,and1.265 A.cm^-2 at 800 ℃ and 1.6 V,respectively.Therefore,SF105O-based SSOC has a high practical promotion value as an energy conversion device,and the synergistic effect of non-traditional perovskite substrate structure and in-situ exsolution modification on the catalytic performance of the electrode needs to be further studied.更多还原