【作者】 潘霞；

【导师】 吴也凡；

【作者基本信息】 景德镇陶瓷学院 ， 材料物理化学， 2011， 硕士

【摘要】 固体氧化物燃料电池的性能和阳极的微观结构密切相关,优化阳极的微观结构可以改善电池的性能。离子浸渍法是制备纳米结构的高性能SOFC电极的重要方法之一。本研究采用离子浸渍法制备固体氧化物燃料电池阳极。为了配合本课题组采用石墨造孔剂制备大规格平板式单电池的需要,本研究首先对石墨的表面进行了改性,通过改善其润湿性和增加其表面含氧官能团,以达到改善其在水系中的分散性;然后以YSZ粉体和造孔剂（硝化石墨）为原料制备了高孔隙率的YSZ多孔层/YSZ致密层复合基体作为浸渍的载体,将其分别浸渍于硝酸镍的饱和溶液与丙酸-镍络合物溶液中,经多次浸渍、干燥、焙烧制备含镍催化剂的半电池,经涂覆阴极得到单电池。采用XRD和SEM对阳极的晶相和微观结构进行了表征,经丙酸-镍络合物溶液浸渍阳极中的NiO晶粒明显小于经饱和硝酸镍溶液浸渍阳极中的NiO晶粒,NiO晶粒均为纳米级;通过添加丙酸,可以增加浸渍溶液中的含镍量,提升浸渍速率,减小NiO晶粒尺寸,抑制NiO团聚,增加阳极三相反应区长度;NiO晶粒尺寸随着丙酸和硝酸镍的摩尔比值（R）的增加呈减小的趋势,晶粒范围在20nm～40nm之间,当R值为1.5时,NiO的晶粒尺寸为20nm;经丙酸-镍络合物溶液浸渍阳极制备的单电池在750℃时的最大功率密度（1.135W/cm²）高于经饱和硝酸镍浸渍阳极制备的单电池的最大功率密度（0.719W/cm²）。对于离子浸渍法制备固体氧化物燃料电池阳极,一个机械性能好、孔隙率高的YSZ多孔层/YSZ致密层复合基体是实验的关键,也是进行下一步实验要解决的首要问题,因此,本研究对YSZ多孔层/YSZ致密层复合基体的制备进行了研究。通过对致密层和多孔层的烧成收缩及石墨的粒径和不同粘结剂对复合基体的影响的研究,确定最佳组合。实验结果表明,采用D50=3μm的石墨粉体在微波条件下稀硝酸硝化改性,将D50=90nm的YSZ粉体与硝化石墨按照质量比为10:7、以PVA作粘结剂制备的YSZ多孔层/YSZ致密层复合基体具有良好的机械性能,且多孔层的孔隙率为50vol.%。另外,本研究还探讨了不同方法制备的阳极、及硝化石墨的含量及镍的浸渍量对单电池电性能的影响。实验结果表明,工作温度为750℃、H₂环境下,以硝化石墨含量为70wt.%的复合基体为载体、NiO的浸渍量为50wt.%时,单电池的功率密度最高。更多还原

【Abstract】 The performance of Solid Oxide Fuel Cell is closely related to the microstructure of the anode,optimization of the microstructure of the anode can improve the performance of the cell. Ion impregnation method is one of the important method which used to prepare nano-structured high–performance SOFC.In this study,we prepared an anode of Solid Oxide Fuel Cell by ion impregnation.In order to meet needs of preparation of big plate single cell which used graphite as pore-maker,first,we used different methods to modify graphite to improve its wettability and to increase the surface oxygen groups,and then to improve the dispersion of graphite in the water systems;then,we used YSZ powder and pore-maker（nitrification graphite）as raw materials to prepare a high porosity YSZ layer / YSZ dense layer complex matrix as the impregnated carriers,then impregnated the carriers in the nickel nitrate saturated solution and the propionic acid -nickel complex solution,respectively. After repeated dipping,drying and calcining,we obtained the half-cell with nickel catalyst,coating the cathode on the half-cell to get the single cell. The crystalline phase and microstructure of anode were characterized by XRD and SEM,the NiO crystal in the anode were both nano-crystal,but the NiO crystal which impregnated in the propionic acid-nickel complex solution is obviously smaller than those impregnated in the nickel nitrate saturated solution;By adding the propionic acid,can increase the content of the nickel in the solution to enhance the impregnation rate ,it also can reduce the size of NiO crystal and inhibit the NiO aggregation to increase the length of the three-phase reaction zone in anode;with the increase of propionic acid and nitric acid molar ratio （R）,the size of the NiO crystal showed a descreasing trend,the range of the NiO crystal was 20nm 40nm,when the R value is 1.5,the size of NiO crystal of 20nm;at 750℃,the maximum power density of single cell which prepared by impregnated in propionic acid -nickel complex solution（1.135W/cm²）is higher than it prepared by impregnated in the nickel nitrate saturated solution（0.719W/cm²）.A YSZ porous layer / YSZ dense layer complex matrix which has good mechanical properties and high porosity is the key to prepare SOFC anode by ions impregnation,and it is the first problem to slove,if we want to do the next experiments. Therefore,in this work,we studied on preparing the YSZ porous layer / YSZ dense complex matrix.We studied on sintering the dense layer and porous layer,and the particle sizes of the graphite and the type of the binder impacting on composite matrix,and then determined the best combination.The experimental results shown that D50=90nm YSZ powder and nitrification graphite powder which was modified in dilute nitric acid under the microwave conditions in accordance with the mass ratio of 10:7,and PVA as binder to prepare YSZ porous layer / YSZ dense layer complex matrix,it had good mechanical properties and the porosity of porous layer is 50vol.%.In addition,in this study,we discussed the different preparation methods on the anode and the content of the nitrification graphite and the amount of catalytic active components by impregnation impacted on electrical properties of single cell. The experimental results showed that the anode which used the complex matrix with 70wt.% nitrification graphite content as a carrier,and NiO-impregnated amount was 50wt.%,operated temperature at 750℃in the H₂ environment,the corresponding single cell has the highest power density.更多还原