Ce0.8 Y0.1 Gd0.1 O1.9电解质的制备及其性能研究

通过溶胶凝胶法制备了Y、Gd共同掺杂的CeO2粉末(Ce0.8Y0.1 Gd0.1O1.9,CYG).并将制得的粉末经1400℃下高温烧结4h得到相应的CYG电解质烧结体.对CYG粉末及烧结体进行了相应的性能测试.实验结果表明:用溶胶凝胶法成功制备出了纳米CYG粉末,所得CYG粉末具有良好的烧结活性,1400℃下烧结所得电解质材料烧结体的相对密度达到95.8%.电导率的测试表明,CYG电解质烧结体在中温范围有较高的电导率,800℃时,其电导率达到了0.084S·cm-1.     

Al2O3掺杂方式对Ce0.8Sm0.2O1.9电解质结构和性能的影响

研究了Al2O3掺杂方式对Ce0.8Sm0.2O1.9 (SDC) 材料性能的影响。用XRD、SEM、XEDS和热膨胀系数仪等检测手段对样品的晶体结构、力学、热学、显微结构和微区元素进行检测分析。结果表明：采用低温燃烧一步合成法制备的样品其力学性能、烧结性和离子电导率均优于采用铝溶胶直接添加法所制备的样品,其主要原因在于铝溶胶直接添加法会在SDC材料中产生残留Al2O3,并富集在晶界处形成晶界夹杂,阻碍了氧离子迁移。     

Sm,Gd共同掺杂的CeO2基电解质性能研究

用Ｓｍ２Ｏ３和Ｇｄ２Ｏ３共同掺杂ＣｅＯ２基电解质组分（ＣｅＯ２）０．９０（Ｓｍ２Ｏ３）０．０５（Ｇｄ２Ｏ３）０．０５）,可以在较低的温度（１４００－１４５０℃）烧结并较高电导率,８００℃时电导率约为７Ｓ．ｍ＾－１。     

La1.9Ba0.1Mo1.9Al0.1O8.8电解质材料的制备及性能研究

采用溶胶-凝胶法制备了电解质材料La1.9Ba0.1Mo1.9 Al0.1O8.8(LBMA),通过热重-差示扫描量热分析(TG-DSC)、X射线衍射(XRD)、透射电镜(TEM)、扫描电镜(SEM)和电化学阻抗谱(EIS)等方法对样品进行测试研究.研究表明干凝胶经700℃煅烧处理即可得到立方相氧化物LBMA,煅烧后的粉体为分散性较好的球形纳米颗粒,平均粒径约为35 nm.SEM分析和致密度研究表明溶胶-凝胶法制备的粉体具有良好的烧结性能,在1100℃烧结2h能得到相对密度高于98％的致密的陶瓷烧结体.电化学性能研究表明LBMA具有较高的离子电导率,1100℃烧结的LBMA电解质在800℃时电导率达到17.87 mS/cm,电导活化能为1.22 eV,其有望应用于中低温固体氧化物燃料电池.     

添加Al2O3对Ce0.8Sm0.2O1.9固体电解质烧结行为和性能的影响

通过凝胶浇注法制备了Al2O3掺杂0～3%（按质量计）的Ce0.8Sm0.2O1.9（samarium doped ceria,SDC）粉体.对所得粉体的相组成和粒度等进行了测定.粉体经模压成形,生坯在1 350～1 450℃烧结5 h,制成Al2O3-SDC固体电解质材料,对该材料样品的密度、微结构、电导率及抗弯强度等进行了测试分析.试验结果表明：掺入适量的Al2O3,所得Al2O3-SDC粉体具有良好的烧结性能,并能使Ce0.8Sm0.2O1.9粉体保持立方萤石结构,其烧结样品具有较高电导率,并且力学性能明显提高.未添加和添加1.0%Al2O3的SDC材料在600℃的电导率分别为0.28 S/cm和0.030 S/cm;室温抗弯强度分别为89.3 MPa和109.7 MPa.     

LaBaCoFeO5+δ-Ce0.8Sm0.2O1.9复合阴极的电化学性能研究

采用固相反应法合成中温固体氧化物燃料电池的LaBaCoFeO5+δ阴极粉末,研究不同煅烧温度对晶体结构的影响.将等量的LaBaCoFeO5+δ和Ce0.8 Sm0.2 O1.9电解质粉末通过机械混合和煅烧制备成LaBaCoFeO5+δ-Ce0.8 Sm0.2 O1.9复合阴极粉末.研究了复合阴极粉末的化学相容性、粒度分布、热膨胀和电化学性能.结果表明,LaBaCoFeO5+δ固相反应的最佳温度为1200℃,LaBaCoFeO5+δ和Ce0.8 Sm0.2 O1.9之间没有发生明显的反应,复合阴极粉末的中位径D50为2.441μm.LaBaCoFeO5+δ-Ce0.8 Sm0.2 O1.9复合阴极比LaBaCoFeO5+δ阴极组成的单电池在800℃的极化电阻下降了约48.7％,而最大输出功率密度提高了约82.5％,表现出更好的电化学性能.     

溶胶凝胶法制备Ce_(0.8)Y_(0.2-x)Ca_xO_(2-δ)电解质材料及其性能

采用溶胶-凝胶法制备出Ce0.8Y0.2-x Cax O2-δ(0.02≤x≤0.10)系列电解质材料。通过红外、热重、X射线衍射、扫描电子显微镜、透射电子显微镜、交流阻抗和热膨胀系数测试对试样进行分析。结果表明:采用溶胶-凝胶法经600℃煅烧所得粉体形成了单相立方萤石结构,平均晶粒尺寸在5~10nm之间;Ce0.8Y0.2-x Cax O2-δ超细粉体具有较高的烧结活性,在1 400℃烧结得到的Ce0.8Y0.2-x Cax O2-δ系列电解质陶瓷的相对密度均大于96%。在该系列材料中,Ce0.8Y0.1Ca0.1O1.85具有良好的离子导电率、较低的电导活化能和适中的热膨胀性能。它在800℃时的离子电导率为0.041S/cm,电导活化能为0.81eV,热膨胀系数为13.5×10-6 K-1(常温~800℃)。     

固体氧化物燃料电池电解质材料 Ce0.8Sm0.2-xCuxO1.9-δ的制备与性能研究

以硝酸铈、硝酸铜、硝酸钐为原料,柠檬酸为络合剂,采用溶胶-凝胶法制备了固体氧化物燃料电池(SOFCs)电解质材料Ce0.8 Sm0.2-x Cux O1.9-δ(x=0、0.02、0.04、0.08、0.12、0.16、0.20),并通过红外光谱(FTIR)、X射线衍射(XRD)、扫描电子显微镜(SEM)、交流阻抗(AC)等技术对样品进行了分析表征.结果表明,采用溶胶-凝胶法经600℃煅烧所得粉体呈现出单相的立方萤石结构,超细粉体Ce0.8 Sm0.2-x Cux O1.9-δ具有较高的烧结活性.经1500℃烧结3 h后得到的Ce0.8 Sm0.2-x Cux O1.9-δ系列电解质陶瓷,其相对密度均大于95％.电化学性能研究表明,Sm、Cu双掺杂可以提高CeO2基电解质的性能.其中,Ce0.8 Sm0.18 Cu0.02 O1.89电导率最大,在800℃时达到0.06 S/cm,活化能为0.33 eV.     

用于固体氧化物燃料电池的Zn掺杂BaZr0.7Pr0.1Y0.2O3-δ质子导体电解质的制备与性能

采用柠檬酸–硝酸盐燃烧法制备了质子导体固体氧化物燃料电池(SOFC)电解质材料BaZr0.7Pr0.1Y0.2O3–δ(BZPY)和BaZr0.7Pr0.1Y0.16Zn0.04O3–δ(BZPYZn)。研究了Zn掺杂对材料烧结、热膨胀系数和电性能的影响;利用X射线衍射仪和扫描电子显微镜对样品物相和微观结构进行了表征。结果表明:BZPYZn经1 100℃煅烧5h后呈单一的钙钛矿结构。随烧结温度的升高(从1 300℃到1400℃),BZPYZn陶瓷体的晶粒尺寸增大,而孔隙率减小;1350℃保温5h烧结的BZPYZn陶瓷样品的相对密度达到97.3%;500～800℃范围内,离子电导率介于10–3～10–2S/cm之间。室温至1 000℃范围内,样品的热膨胀系数为9.2×10–6/K,表明其与电极材料(Ni)的热匹配性好。预示BZPYZn有望成为良好的质子传导型中温SOFC电解质材料。     

用柠檬酸-硝酸盐合成La0.8Sr0.2Ga0.85Mg0.15O3-δ及其性能

用柠檬酸-硝酸盐水系溶液为前驱体合成了具有钙钛矿结构的中温电解质La_(0.8)Sr_(0.2)Ga_(0.85)Mg_(0.15)O_(3-s-δ)(LSGM)。用DTA-TGA和X射线衍射仪分析了LSGM材料中钙钛矿相的形成过程,用热膨胀仪和交流复阻抗谱研究了样品的烧结、热膨胀和电学性能。研究结果表明:用柠檬酸-硝酸盐溶液制备LSGM所得到的非晶产物在800℃时开始形成钙钛矿相,1400℃烧结6 h已经完全转变成稳定钙钛矿相,LSGM样品在1450℃烧结6 h,相对密度已经达到98％。1450℃烧结6 h的LSGM样品阻抗谱研究表明:与固相法制备的LSGM相比,用柠檬酸-硝酸盐溶液合成的LSGM晶界电阻和杂相电阻都很小,不影响样品的电导。表明用湿化学法合成LSGM有利于提高纯度,改善导电性能。850℃时样品的电导率为6.0×10~(-2)S/cm,900℃时单电池的最大输出功率密度为12.2 mW/cm~2,短路电流密度达刭55.2 mA/cm~2。     

Preparation of ultra-fine Sm0.2Ce0.8O1.9 powder by a novel solid state reaction and fabrication of dense Sm0.2Ce0.8O1.9 electrolyte film

A novel solid state reaction was adopted to prepare Sm_0.2Ce_0.8O_1.9 (SDC) powder. A mixed oxalate Sm_0.2Ce_0.8(C₂O₄)_1.5·2H₂O was synthesized by milling a mixture of cerium acetate hydrate, samarium acetate hydrate, and oxalic acid for 5 h at room temperature. An ultra-fine SDC powder with the primary particle size of 5.5 nm was obtained at 300 °C. The ultra-low temperature for the formation of SDC phase was due to the atomic level mixture of the Sm³⁺ and Ce⁴⁺ ions. The crystal sizes of SDC powders at 300 °C, 550 °C, 800 °C, and 1050 °C were 5.5 nm, 11.4 nm, 24.1 nm and 37.5 nm, respectively. The sintering curves showed that the powder calcined at lower temperature was easier to be sintered owning to its smaller particle size. A solid oxide electrolytic cell (SOEC), comprising porous La_0.8Sr_0.2Cu_0.1Fe_0.9O_3−δ (LSCF) for substrate, LSCF–SDC for active electrode, SDC for electrolyte, and LSCF–SDC for symmetric electrode, was fabricated by dip-coating and co-sintering techniques. An extremely dense SDC film with the thickness of 20 μm was obtained at only 1200 °C, which was about 100–300 °C lower than the literatures׳ reports. The designed SOEC was proved to work effectively for decomposing NO (3500 ppm, balanced in N₂), 80% NO can be decomposed at 600 °C.     

Ce_(0.8)Sm_(0.2)O_(1.9)-BaCe_(0.8)Sm_(0.2)O_(2.9)复合电解质的晶界电导

分别采用机械混合法和一步溶胶-凝胶法制备摩尔比为1:1的Ce_(0.8)Sm_(0.2)O_(1.9)(SDC)-BaCe_(0.8)Sm_(0.2)O_(2.9)(BCS)复合电解质,研究了不同制备方法对复合电解质SDC-BCS的显微结构以及电化学性能的影响。结果表明:相比于机械混合法,一步溶胶-凝胶法制得的复合电解质中的SDC和BCS两相的分布更加均匀;且与单相电解质SDC相比,复合电解质中SDC和BCS的相界能够为质子和氧离子提供传输通道,有利于晶界电导率的提高。另外,一步溶胶-凝胶法制备的复合电解质制作的单电池,具有较高的开路电压和最大功率密度,在700℃时分别达到0.914 V和0.281 W/cm~2。     

Aqueous processing of Ce0.8Sm0.2O1.9 green tapes

An aqueous tape casting of Ce_0.8Sm_0.2O_1.9 (SDC) ceramics was developed using poly(acrylic acid) (PAA) as dispersant, poly(vinyl alcohol) (PVA) as binder, poly(ethylene glycol) (PEG) as plasticizer, and deionized water as solvent. Surface properties of SDC powder with and without PAA dispersant were characterized by electrokinetic measurements. The rheology of the SDC slurries was evaluated with a rotary viscometer. The zeta potential measurement showed that the isoelectric point (IEP) for SDC powders in the absence of dispersant corresponds to a pH value of 3.66. The experimental results showed that the pH value greatly affects the rheology of the slurry. The optimum content to get a stable dispersed slurry is 2 wt% PAA in pH value range of 9–10. In presence of 2 wt% PAA dispersant, 55 wt% SDC powders exhibited shear thinning behavior, indicating that SDC slurry was homogenous and well stabilized. Homogeneous, smooth, and defect-free green tapes were successfully obtained by an appropriate slurry formula.     

自蔓延低温燃烧-溶胶凝胶合成Ce0.8Sm0.2O1.9及烧结性能

用甘氨酸作还原剂、硝酸盐作氧化剂,采用溶胶-凝胶与自蔓延低温燃烧相结合的方法制备了超细Ce_0.8Sm_0.2O_1.9 (SDC)固溶体,对所合成的粉体分别采用XRD、SEM和BET法进行了表征。结果表明,600℃焙烧产物是具有较高相纯度的单一立方相萤石型结构固溶体,根据XRD估算晶粒度为13～30 nm。甘氨酸与金属硝酸盐(G/N)摩尔比对粉体的微观形貌和烧结性能有很大影响, 当G/N相似文献   

溶胶-凝胶低温燃烧合成法制备Sm0.15Gd0.05Ce0.8O1.9纳米粉体

采用溶胶-凝胶与低温自蔓延燃烧相结合的方法合成了纳米级超细Sm0.15Gd0.05Ce0.8O1．9粉体，选用的合成体系有：柠檬酸-硝酸盐，甘氨酸-硝酸盐，EDTA络合-硝酸盐等方法。对所合成粉体进行了XRD，TEM及激光Raman光谱仪(laser Raman spectroscope，LRS)检测，研究了不同方法制备的粉体的结构及晶相。结果表明：XRD和LRS相结合能较好地表征固溶体的结构和纯度，几种方法合成的粉体为纯度高的掺杂氧化铈固溶体，晶粒尺寸较均匀，但分散性差。影响最终合成的超细粉体粒径的因素有：有机络合剂的种类、性质，有机络合剂与总金属阳离子比例及形成掺杂固溶体所需的温度。     

草酸盐共沉淀法制备Ce0.8Y0.2O1.9超细氧化物固溶体

实验采用草酸二乙酯、Ce(NO_3)_3·6H_2O、Y(NO_3)_3·6H_2O为原料,以尿素为pH值调节剂,利用均相共沉淀法制备了20%(摩尔分数)Y_2O_3掺杂CeO_2(Ce_(0.8)Y_(0.2)O_(1.9))的氧化物前驱体,通过优化沉淀反应过程中尿素用量、pH值及沉淀物醇洗和干燥处理等制备工艺条件,实现对草酸盐沉淀物的制备过程中的团聚控制,得到分散良好的亚微米级草酸盐共沉淀物,进一步选择合适的热处理温度,得到亚微米级的超细Ce_(0.8)Y_(0.2)O_(1.9)粉体。     

Performance of IT‐SOFC with Ce0.9Gd0.1O1.95 Functional Layer at the Interface of Ce0.9Gd0.1O1.95 Electrolyte and Ni‐Ce0.9Gd0.1O1.95 Anode

In this paper we present results for a high power density IT‐SOFC and a method for dispersing nanosized Ce_0.9Gd_0.1O_1.95 (GDC) particles at the GDC electrolyte and Ni‐GDC anode interface. Dispersed nanosized particles were deposited to form an anode functional layer (AFL). Anode supports were prepared by tape casting of large micron‐sized NiO powder and sub micron‐sized GDC powder without pore former. For the cathode a La_0.6Sr_0.4Co_0.2Fe_0.8O_{3 – δ} (LSCF)‐GDC composite was used. Without an AFL the open circuit potential (OCP) and the maximum power density were 0.677 V and 407 mW cm^–2, respectively, at 650 °C using 30 sccm of hydrogen and air flow‐rate. With an AFL the OCP and the maximum power density increased to 0.796 V and 994 mW cm^–2, respectively, at the same temperature. Two point probe impedance measurements revealed that the AFL fabricated by the proposed method not only increased the OCP but also reduced the electrode polarisation by 68%. The effect of gas flow‐rate is also present in this paper. When hydrogen and air flow‐rate is increased to 90 sccm, the sample with AFL obtained 1.57 W cm^–2 at 650 °C.