固体氧化物燃料电池阳极材料的流延制备和电池性能研究

利用流延法制备NiO-YSZ阳极，采用磁控溅射、多层流延法制备YSZ电解质薄膜，丝网印刷制备BSCF-YSZ阴极，制备出Ni-YSZ／YSZ／BSCF-YSZ单电池。阳极制备中探索了浆料配比对生坯性能的影响；研究了不同造孔剂得到的流延阳极的微结构形貌差异。考察了双层流延、磁控溅射制备YSZ薄膜的微观结构，并测试评价了电池性能。     

固体氧化物电解池铁酸锶镧基复合阳极的制备及性能研究

分别采用丝网印刷和浸渍法两种工艺制备了固体氧化物电解池(SOEC)铁酸锶镧(LSF)基复合阳极,通过XRD、TEM、SEM等手段对LSF粉体和复合材料的相结构和微观结构进行了分析,利用电位扫描以及电化学阻抗谱(EIS)比较了这些复合阳极在SOEC工作温度800-C时的电化学性能.结果表明,采用共沉淀-共沸蒸馏(CP-AD)合成的LSF20(La0.8Sr0.2FeO3-δ)粉体粒径约为20～30nm,其都分布在氧化锆(YSZ)陶瓷骨架上;800℃时,浸渍法工艺制备的LSF20-YSZ复合阳极在0.1V极化过电位下的极化电流值为0.38～0.49A/cm2,约为丝网印刷工艺制备的电化学性能的2～2.5倍.     

YSZ纳米粉料流延成型电解质薄膜性能研究

探索了以YSZ纳米粉体为原料,采用流延成型的方法制备YSZ电解质薄膜的工艺过程,具体探讨了不同粒度粉体流延后坯体的性能,结果表明,纳米范围内颗粒粒度粗可以获得致密度较高的坯体。但在烧结过程中,细粒度粉料表现出更好的性能,实验制备的YSZ电解质薄膜的面积比电阻在1123K,比德国D样品大幅度下降。573～1023K的阻抗谱显示出实验制备的YSZ电解质试样的晶粒、晶界和电极处的阻抗都明显降低,综合性能明显优于国外同类产品。流延成型工艺可以获得尺寸为100mm×100mm×0.125mm的8YSZ电解质薄片,这为平板式SOFC在中国的快速发展做好了材料上的准备。     

IT-SOFC阳极制备中催化剂NiO化学浸渍法的研究

在中温固体氧化物燃料电池(IT-SOFC)阳极的制备中,采用氨水、饱和硝酸镍溶液为原料,利用化学浸渍法引入催化剂NiO制备阳极;利用本实验室制备好的致密薄膜YSZ-多孔YSZ烧结复合体在氨水中浸渍,然后放入饱和硝酸镍中负压浸渍使得两种溶液在多孔YSZ的微孔中进行反应.计算结果表明:该法一次浸渍可增重NiO 17.2％(质量分数),是普通浸渍法(用致密薄膜YSZ-多孔YSZ烧结复合体在硝酸镍溶液中浸渍,包括常压浸渍与负压浸渍)一次浸渍增重量的3倍左右.采用场发射扫瞄电子显微镜观察多孔YSZ阳极的断面,比较了普通浸渍法和化学浸渍法催化剂NiO的一次浸渍量;对比了化学浸渍和(通常使用的)直接混合引进催化剂NiO所制备的阳极中NiO颗粒的形态.研究结果表明:采用化学浸渍法引入NiO制备阳极较普通浸渍法简化了工艺且大大缩短了制备周期.利用该法制备的单电池,其电性能明显高于利用直接混合引入催化剂NiO制备阳极的单电池.700℃,H2为燃料,空气为氧化剂,前者的最大输出功率密度达0.83W/cm2,后者的最大输出功率密度仅为0.43W/cm2.     

YSZ/YSZ-NiO电解质薄膜在低温条件下的电学特性研究

采用脉冲激光沉积(PLD)法,在多孔支撑的NiO-YSZ阳极基底上制备YSZ电解质薄膜。利用XRD、SEM和射频阻抗/材料分析仪对多层膜的物相结构、表面形貌以及电学特性等进行表征。实验结果发现,YSZ电解质薄膜在300-500℃之间,其电导活化能最小值为0.86e V,电导率可达到7.96×10-5s/cm。     

热处理温度对磁控溅射法制备YSZ电解质薄膜性能的影响

采用射频磁控溅射方法在NiO-YSZ阳极基底上制备了致密的YSZ电解质薄膜,主要研究了热处理温度对电解质薄膜性能的影响.试验发现随着热处理温度的提高,所制备的YSZ薄膜中晶粒结合更加致密,气孔率显著降低,薄膜与基底间的结合更加紧密.通过组装单体电池实际考察了薄膜的性能,发现随着热处理温度的提高,电池的开路电压及放电性能均有大幅度的提高.在800℃下,开路电压由0.82V提高到1.023V,已接近SOFC的理论电压;最大功率密度由480mW/cm2提高到760 mW/cm2.     

固体氧化物燃料电池电解质10Sc1CeSZ的固液复合合成方法研究

结合当前国内外关于固体氧化物燃料电池电解质10Sc1CeSZ合成技术的研究现状,提出了一种新颖的合成方法,即固液复合法(SLM),这种方法具有低成本和环境友好的特点,表现出良好的应用潜力。主要考察了氧化锆比表面积对粉体晶体结构的影响,并探讨了该方法的主要合成机理。结果表明,氧化锆比表面积大于60m2/g时可以获得纯的立方相粉体。与传统的共沉淀合成法相比,SLM法合成的粉体具有更好的微结构和烧结性能、电解质性能。烧结后的电解质片的电导率在10Sc1CeSZ电解质中处于较高水平,在800℃时达到了0.14S/cm。     

铝箔表面复合阳极氧化膜研究

采用溶液浸渍法在低压腐蚀铝箔表面沉积一层Ti氧化物．然后将试样在有机盐水溶液中阳极氧化至20．0V。在恒流升压过程中,记录电压-时间曲线。借助XPS和XRD等分析手段分析阳极氧化膜结构,并对复合阳极氧化膜的生长机理进行了探讨。结果表明：含Ti处理液浸渍处理后,试样阳极氧化的电压-时间曲线斜率显著增大,阳极氧化膜是由Al2O3和TiO2构成的复合阳极氧化膜,其介电常数高于Al2O3阳极氧化膜,使阳极箔比容提高24．8％。     

泥浆喷涂制备阳极支撑YSZ电解质薄膜工艺研究

采用泥浆喷涂工艺制备SOFC用阳极支撑YSZ电解质薄膜,首先采用模压成型工艺制窷iO-YSZ阳北极基底,通过优化泥浆制备工艺条件及喷涂条件,在NiO-YSZ阳极基底上喷涂均匀平整的YSZ电解质涂层,进一步采用共烧结工艺使YSZ电解质层致密.通过在基底中添加碳粉造孔剂,调节阳极基底的烧结收缩率与电解质层烧结收缩率一致,避免电解质涂层的开裂和变形.阳极基底中加入5wt%含量的碳粉,阳极与电解质层烧结收缩率一致.扫描电子显微镜观察电解质涂层表面形貌表明,球磨24h的泥浆喷涂的YSZ涂层较好,阳极基底与电解质膜在1400℃烧结2h,电解质膜层致密,表明通过泥浆喷涂工艺可以制备出致密电解质层.     

恒压电泳制备YSZ电解质膜的研究

为了降低固体氧化物燃料电池(SOFC)的操作温度,采用恒压电泳沉积方法在NiO-YSZ阳极基体上制备了YSZ电解质薄膜,通过电泳沉积电流的测量及SEM测试,研究了不同分散介质对悬浮体系稳定性及YSZ膜微观结构的影响,分析了I2、PVB作为添加剂在电泳沉积过程中的作用机理.实验结果表明,使用丙酮作为分散介质,并加入0.5 g/L的I2时,能够获得较稳定的悬浮液.在其中加入0.3 g/L的PVB能够增强YSZ颗粒间的作用力,提高YSZ膜的致密性.研究认为,电泳沉积悬浮液的组成对沉积电流和沉积膜的微观形貌都具有较大影响.     

Granular nanocrystalline zirconia electrolyte layers deposited on porous SOFC cathode substrates

Thin granular yttria-stabilized zirconia (YSZ) electrolyte layers were prepared by chemical vapor synthesis and deposition (CVD/CVS) on a porous substoichiometric lanthanum–strontium–manganite (ULSM) solid oxide fuel cell cathode substrate. The substrate porosity was optimized with a screen printed fine porous buffer layer. Structural analysis by scanning electron microscopy showed a homogeneous, granular nanocrystalline layer with a microstructure that was controlled via reactor settings. The CVD/CVS gas-phase process enabled the deposition of crack-free granular YSZ films on porous ULSM substrates. The electrolyte layers characterized with impedance spectroscopy exhibited enhanced grain boundary conductivity.     

溶胶浸渗处理对EB-PVD 制备的YSZ电解质涂层的影响

为探索溶胶浸渗处理对电子束物理气相沉积(EB-PVD)制备8%摩尔比的氧化钇稳定氧化锆(8YSZ)涂层微观结构及性能的影响,采用EB-PVD工艺在沉积速率1μm/min的条件下制备了8YSZ电解质涂层.制备态涂层的断面表现为疏松的柱状晶结构,导致涂层的气密性差,因此对涂层进行了溶胶浸渗处理,即首先在负压下将涂层浸渗在钇锆的溶胶内,再进行550℃保温2 h的热处理.SEM分析表明,溶胶分解产物可以堵塞柱状晶间的孔隙,其渗入涂层的深度可达3μm.浸渗处理后,涂层的气体扩散系数由未处理态的6.78×10-5cm4/(N.s)降低至8次浸渗处理后的6.54×10-6cm4/(N.s).8次溶胶浸渗处理后涂层的电导率相比处理前提高不超过10%.     

用于制备SOFC电解质膜Sm0.2Ce0.8O1.9的合成及性能研究

分别采用硝酸盐－苷氨酸燃烧法、固相法和柠檬酸硝酸盐法制备了钐掺杂的氧化铈电解质材料Sm_0.2Ce_0.8O_1.9 (SDC).采用这三种方法合成的SDC粉末通过料浆喷涂法在多孔的NiO-SDC阳极基底上制备了SDC电解质膜.采用丝网印刷在SDC电解质膜表面制备了Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ (BSCF)新型阴极,进而制备成固体氧化物燃料电池（SOFCs）单电池.采用CHI604B电化学工作站对电池性能进行了测试.采用粒径分析仪对粉末的粒度分布进行了分析.利用扫描电镜（SEM）对合成的粉末和电池的微观结构进行了观察和研究.结果表明,柠檬酸硝酸盐法合成的SDC粉末能够满足料浆喷涂法制备SOFCs薄膜电解质的要求.     

Electric field-assisted pressureless sintering of zirconia–scandia–ceria solid electrolytes

Electric field-assisted (flash) pressureless sintering experiments were carried out in ZrO₂ ceramics doped with 10 mol% Sc₂O₃ and 1 mol% CeO₂ (10Sc1CeSZ). All experiments were conducted isothermally at 1050 °C for 2–5 min with the application of a 100–150 V cm^?1 AC electric field at 1 kHz with 1–4 A limiting current in green compacts and in samples pre-sintered at different temperatures. Shrinkage level, structural phases and grain morphology data were collected by dilatometry, X-ray diffraction and scanning electron microscopy analyses, respectively. The results showed that for the same delivered electric power, the final shrinkage was higher for higher temperature applications of the electric field and for higher electric current pulses. Moreover, the higher the porosity, the higher the final densification of the flash-sintered 10Sc1CeSZ samples, showing that pores play a role as a preferential path in the flash sintering mechanism.     

YSZ薄膜的制备及应用

研究了在ＮＡＳＩＣＯＮ基板上使用溅射法制备的ＹＳＺ薄膜的结构,晶相和导电性,实验表明,刚制备的ＹＳＺ薄膜７５０℃常规退火处理后,薄膜表面致密、均匀、无裂纹,具备良好的导电性能,ＹＳＺ／ＮＡＳＩＣＯＮ组合再加上Ｂａ（ＮＯ３）２辅助电极构成的ＮＯｘ气体传感器在４５０℃下响应迅速（响应时间约为３ｍｉｎ）、稳定、能检测到１０ｐｐｍ量级的ＮＯ２气体。     

The influence of electrodes on the strength of planar zirconia solid oxide fuel cells

The strength of symmetric anode/electrolyte/anode and cathode/electrolyte/cathode planar multiple electrode assemblies (MEAs), fabricated by screen printing electrodes onto pre-fired tape-cast electrolyte plates was measured in biaxial flexure. The electrolyte was Zr_0.84Y_0.16O_1.92 (YSZ), the anode NiO/YSZ and the cathode La_0.75Sr_0.2MnO_3–. The residual stress in the electrodes was estimated by curvature measurement after removal of one electrode. The residual stress in the anodes was very low (11 MPa) due to stress relief by extensive channel cracking. The residual stress in the cathodes was much higher (39 MPa) and was in reasonable agreement with the expected thermoelastic stress. The applied load at failure, and the stress in the electrolyte at failure (343 MPa), for anode MEAs were almost equal to those of electrolyte plates (374 MPa). This is consistent with the low residual stress and observed crack deflection by delamination at the anode/electrolyte interface. The applied load at failure, and the stress in the electrolyte at failure (182 MPa), for cathode MEAs were much lower. This is partially explained by the residual stress in the cathode acting to increase the applied stress intensity at defects in the electrolyte, but this effect is not large enough to explain fully the reduced strength.     

YSZ/Ni-YSZ双层中空纤维电解质层厚度控制及其影响

本研究利用相转化共纺丝法一步制备出微管式固体氧化物燃料电池(MT-SOFC)用电解质/阳极(YSZ/NiO-YSZ)双层中空纤维膜, 将制得的YSZ/NiO-YSZ双层中空纤维膜前驱体经1450℃烧结后, 以纯H₂在700℃下还原4 h得到YSZ/Ni-YSZ双层中空纤维膜。电解质YSZ膜层厚度通过改变YSZ铸膜液挤出速率来调节。将La_0.8Sr_0.2MnO_3-δ(LSM)阴极乳浆浸渍涂覆在烧结后的YSZ/NiO-YSZ双层中空纤维膜外, 经1200℃烧结后形成微管式固体氧化物燃料电池。结果表明, 当阳极铸膜液以10?mL/min速率挤出, 而电解质铸膜液挤出速率为0.5、1、1.5、2 mL/min时, 构造的YSZ/Ni-YSZ双层中空纤维膜电解质层厚度分别为6、13、18、28 μm, 其机械强度、气密性均随着电解质层厚度增加而增大, 但电导率与孔隙率受电解质层厚度的影响较小。YSZ膜厚度为28 μm的MT-SOFC, 800℃时以20 mL/min氢气作为燃料, 30 mL/min空气作为氧化剂, 最大开路电压为1.01 V, 最大输出功率只有75 mW/cm²。但同样测试条件下, YSZ膜厚度为6 μm的MT-SOFC, 开路电压为0.92 V, 最大输出功率升至329 mW/cm²。     

YSZ电解质薄膜制备工艺进展

电解质作为固体氧化物燃料电池(SOFC)的关键组件,很大程度上决定着燃料电池性能的优劣和成本的高低.钇稳定氧化锆(YSZ)因其优良的综合性能,一直是SOFC最具竞争力的电解质材料之一,因此开发YSZ电解质工艺已成为人们关注和研究的热点.论述了制备YSZ电解质薄膜的主要方法,并对这些方法进行了评述和展望.     

Characterization of electrolyte films deposited by using RF magnetron sputtering a 20 mol% gadolinia-doped ceria target

20 mol% Gd-doped ceria (20GDC) electrolyte films on poly-crystalline Al₂O₃ substrates were prepared by radio frequency (RF) magnetron sputtering from a 20GDC oxide target, which was made by the processes of colloidal dispersion-pressure casting-sintering. Material characteristics of the 20GDC oxide target and the deposited films before and after annealed at 900 °C for 2 h were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and conductivity measurements. Crack-free and dense 20GDC electrolyte films were observed by the deposition conditions of 200 W (RF power). Homogeneity tests revealed the chemical compositions (Ce and Gd) were uniformly distributed through the bulk of the target and the deposited films. 20GDC film with a comparable conductivity of 1.00 × 10^− 3 S/cm at 650 °C is higher than that of bulk yttria-stabilized zirconia (YSZ), but smaller than that of bulk GDCs (10GDC and 20 GDC). Sputtered-GDC films in this study can be also suggested to be used as the electrolyte films for solid oxide fuel cells (SOFCs) systems as compared to the well-known YSZ.     

Device optimization of CO2 gas sensor using planar technology

A planar type Li+ ion based potentiometric CO2 micro gas sensor of size 2 x 3 mm has been fabricated on alumina substrate by combining thin and thick film technology. The heater, electrodes and electrolyte were deposited by thin film deposition technique and the sensing and reference electrodes were printed by silk screen printing technology. The optimal thickness and sintering temperature of electrolyte are 1.2 microm and 775 degrees C. The sensor with Li2CO3 and 20 mol% BaCO3 not only exhibits a good Nernstian behavior but also consistent results over a long time at 450 degrees C in dry as well as 70% RH humidity condition between 160-5000 ppm CO2 concentrations. The spreading effect of the sensing and reference materials was controlled by the addition of Al2O3:B2O3 (1:2 mol%) glass.