La0.8Sr0.2Ga0.8Mg0.2O3－α陶瓷的质子导电性能研究

采用溶胶-凝胶法合成了La_0.8Sr_0.2Ga_0.8Mg_0.2O_3－a陶瓷样品, 用XRD, DSC-TGA, SEM, 交流阻抗谱, 气体浓差电池及气体电化学透过等方法对样品的结构和性质进行了表征和测试. 首次对该样品的质子导电性能进行了研究. 该陶瓷样品具有良好的微观结构, 相对密度达95.1%; 氢浓差电池电动势的实测值与理论值吻合, 离子迁移数为1; 在干燥的氧气气氛中是一个纯的氧离子导体; 氢的电化学透过速率的实测值与理论值吻合, 证明该样品在氢气气氛中几乎是一个纯的质子导体, 质子电导率在1000 ℃时高达0.14 S•cm^－1.     

La0.9Sr0.1Ga0.8Mg0.2O3-α的微乳液法合成及其质子导电性研究

采用微乳液法合成了La_0.9Sr_0.1Ga_0.8Mg_0.2O_3-α的共沉淀前驱体，经初烧和烧结后制得La_0.9Sr_0.1Ga_0.8Mg_0.2O_3-α陶瓷样品，TEM和SEM分析结果表明陶瓷样品具有良好的微观结构，XRD分析结果表明陶瓷样品已形成了单相的LaGaO₃钙钛     

La0.8Sr0.2Ga0.8Mg0.2O2.8的电化学性质及其在SOFC中的应用

采用凝胶浇注法制备具有较高氧离子电导率的固体电解质La0.8Sr0.2Ga0.8Mg0.2O2.8粉料.X射线衍射结果表明,于1400℃焙烧后即形成了钙钛矿结构,无杂相存在.探讨了粉料压制坯体的致密化和导电性能在1450℃下与烧结时间的关系,发现烧结时间为18h时其相对密度达98.3%,而在24h的情况下,样品具有最佳的氧离子导电性.采用Ni-Ce0.8Gd0.2O1.9作为阳极,La0.8Sr0.2Ga0.6Ni0.4O2.7作为阴极,组装了平板型固体氧化物燃料电池(SOFC).阳极和阴极分别通入含3%H2O的氢气和空气,750℃时的开路电压为1.04V,最大输出功率密度(P)达252mW/cm2(U=0.48V,J=525mA/cm2).     

质子导体BaCe0.8Lu0.2O3-α的电性能

采用高温固相法制备了BaCe_0.8Lu_0.2O_3-α质子导体。运用X射线衍射仪（XRD）、扫描电镜（SEM）对该材料的物相结构、微观形貌进行了表征。在500~900℃温度范围内,应用交流阻抗谱和气体浓差电池方法研究了材料在不同气体气氛中的离子导电性和氢-空气燃料电池性能。结果表明,BaCe_0.8Lu_0.2O_3-α材料为单一斜方晶结构,具有良好的致密性。在500~900℃温度范围内,干燥或湿润的氮气、空气和氧气中,材料的电导率随着氧分压增大稍有增大。在湿润的氢气中,材料表现为纯的质子导电性。在以该材料为固体电解质的氢-空气燃料电池条件下,材料表现为质子、氧离子和电子的混合导电性,其中离子导电性始终占主导;氢-空气燃料电池在900℃下的最大输出功率密度为92.2mW·cm^-2,高于我们以前报道的BaCe_0.8RE_0.2O_3-α（RE=Pr,Eu,Ho,Er,等）材料。     

新型氧离子导体La2Mo1.8Ga0.2O9陶瓷的合成及其电性能

通过高温固相合成法首次合成了La₂Mo_1.8Ga_0.2O₉陶瓷样品. 粉末XRD结果表明, 该样品为单一立方相La₂Mo₂O₉结构. 以陶瓷样品为固体电解质、多孔性铂为电极, 采用交流阻抗谱、气体浓差电池、氧泵等方法研究了样品在600～1000 ℃下各种气氛中的离子导电特性. 结果表明, 氧浓差电池电动势的实测值与理论值吻合得很好, 氧离子迁移数为1, 表明该陶瓷样品在该温度下氧气气氛中为一纯氧离子导体; 氧泵(氧的电化学透过)实验结果进一步证实了该样品在氧气气氛中为一纯氧离子导体; 在氧分压p(O₂)＝10^－5～10⁵ Pa的高氧分压气氛中, 电导率与氧分压变化基本无关, 表明在该氧分压范围内样品为纯离子导体, 这与氧浓差电池电动势测定结果相吻合; 在低氧分压为10^－5～10^－15 Pa范围内, 总电导率随氧分压降低而稍有升高, 表明在该氧分压范围样品为氧离子与电子的混合导体; 在600～1000 ℃下氧离子电导率＞10^－2 S•cm^－1, 显著高于母体La₂Mo₂O₉的氧离子电导率, 1000 ℃时的氧离子电导率为0.07 S•cm^－1.     

BaxCe0.8Y0.2O3-α固体电解质的氧离子导电性

Ba_xCe_0.8Y_0.2O_3-α(x=1.03，1，0.98) solid electrolyte samples show a single phase of orthorhombic perovskite of BaCeO₃. The oxide-ion conduction and transport number were detected in the temperature of 600～1000℃ by electrochemical oxygen permeation (oxygen pumping)， and compared with the results from the oxygen concentration cell. The relation between the ingredient of Ba and oxide-ion conduction was also researched. It was found that these electrolytes exhibited the mixed oxide-ionic and electronic hole conduction under the experimental temperature and oxygen gas. The oxide-ion transport numbers are 0.1～0.6， which are close to the results of the oxygen con-centration cell. They increase as the decrease of Ba content in the samples.     

新型氧离子导体La2Mo1.8Ga0.2O9陶瓷的合成及其电性能

通过高温固相合成法首次合成了La₂Mo_1.8Ga_0.2O₉陶瓷样品. 粉末XRD结果表明, 该样品为单一立方相La₂Mo₂O₉结构. 以陶瓷样品为固体电解质、多孔性铂为电极, 采用交流阻抗谱、气体浓差电池、氧泵等方法研究了样品在600～1000 ℃下各种气氛中的离子导电特性. 结果表明, 氧浓差电池电动势的实测值与理论值吻合得很好, 氧离子迁移数为1, 表明该陶瓷样品在该温度下氧气气氛中为一纯氧离子导体; 氧泵(氧的电化学透过)实验结果进一步证实了该样品在氧气气氛中为一纯氧离子导体; 在氧分压p(O₂)＝10^－5～10⁵ Pa的高氧分压气氛中, 电导率与氧分压变化基本无关, 表明在该氧分压范围内样品为纯离子导体, 这与氧浓差电池电动势测定结果相吻合; 在低氧分压为10^－5～10^－15 Pa范围内, 总电导率随氧分压降低而稍有升高, 表明在该氧分压范围样品为氧离子与电子的混合导体; 在600～1000 ℃下氧离子电导率＞10^－2 S•cm^－1, 显著高于母体La₂Mo₂O₉的氧离子电导率, 1000 ℃时的氧离子电导率为0.07 S•cm^－1.     

Ba0.95Ce0.8Ho0.2O3-α的离子导电性

用高温固相反应法制备了Ba_0.95Ce_0.8Ho_0.2O_3-α，X–射线衍射表明，该材料为单相钙钛矿型斜方晶结构。以该材料为固体电解质，多孔性铂为电极，用气体浓差电池方法和交流阻抗谱方法分别测定了材料在600 ~ 1000℃温度范围，潮湿氢气、干燥和潮湿的空气中的离子迁移数和电导率，研究了该材料的离子导电性，并与BaCe_0.8Ho_0.2O_3-α作了比较。结果表明，在600 ~ 700 ℃、潮湿氢气中，Ba_0.95Ce_0.8Ho_0.2O_3-α是纯的质子导体，质子迁移数为1；在800 ~ 1000 ℃，是质子和电子的混合导体，质子迁移数为0.97 ~ 0.93。而BaCe_0.8Ho_0.2O_3-α在潮湿氢气中几乎是纯的质子导体，在600 ~ 900 ℃，质子迁移数为1；在1000 ℃，质子迁移数为为0.99。在600 ~ 1000℃温度范围内、干燥的空气中，它们都是氧离子和电子空穴的混合导体，氧离子迁移数分别为0.24 ~ 0.33和0.17 ~ 0.30；在潮湿的空气中，它们都是质子、氧离子和电子空穴的混合导体，质子迁移数分别为0.11 ~ 0.00 和0.09 ~ 0.01，氧离子迁移数分别为0.41 ~ 0.33和0.27 ~ 0.30。在潮湿的氢气和空气中，在600 ~ 800 ℃温度范围内，Ba_0.95Ce_0.8Ho_0.2O_3-α的质子电导率高于BaCe_0.8Ho_0.2O_3-α，但在800 ~ 1000 ℃温度范围内，Ba_0.95Ce_0.8Ho_0.2O_3-α的质子电导率则低于BaCe_0.8Ho_0.2O_3-α。在600 ~ 1000 ℃温度范围内、潮湿和干燥的空气中，氧离子电导率总是高于BaCe_0.8Ho_0.2O_3-α。     

BaCe0.7Zr0.2La0.1O3-α陶瓷的制备和导电性

以高温固相反应法合成了BaCe_0.7Zr_0.2La_0.1O_3-α陶瓷。粉末XRD结果表明,该陶瓷材料为单一钙钛矿型BaCeO₃斜方晶结构。以陶瓷材料为固体电解质、多孔性铂为电极,采用交流阻抗谱技术和气体浓差电池方法分别测定了材料在500～900 ℃下,干燥空气、湿润空气和湿润氢气中的电导率以及离子迁移数,研究了材料的离子导电特性。结果表明,在500～900 ℃下干燥空气中,陶瓷材料的最大电导率为1.8 mS·cm^-1,氧离子迁移数为0.14～0.04,是一个氧离子与电子空穴的混合导体。在湿润空气中,陶瓷材料的最大电导率为2.0 mS·cm^-1,质子迁移数为0.48～0,氧离子迁移数为0.25～0.10,是质子、氧离子和电子空穴的混合导体。在湿润氢气中,陶瓷材料的最大电导率为3.6 mS·cm^-1。在500～700 ℃温度范围内,陶瓷材料的质子迁移数为1,是纯的质子导体;而在800～900 ℃温度范围内,陶瓷材料的质子迁移数为0.93～0.91,是质子与电子的混合导体,质子电导占主导。     

LiV3O8的合成及其电化学性能研究

The layered trivanadate, LiV₃O₈, was prepared by sol-gel method with LiOH, V₂O₅ and H₂O₂ as initial reagents. The materials at different heat treatment conditions were characterized by XRD and TG-DTA. Their electrochemical behaviors were studied by galvanostatic charge-discharge and cyclic voltammetry. The results show that LiV₃O₈ prepared by sintering at 300 ℃ for 16 h has higher capacity, and its initial discharge capacity is 333.1 mAh·g^-1, and maintains a discharge capacity of 302.8 mAh·g^-1 after 10 cycles at 0.2 C and the voltage range of 1.8～4.0 V.     

Ce0.8Sm0.2O1.9的尿素燃烧法合成与性能

采用以尿素为燃料的燃烧合成法制备Ce0.8Sm0.2O1.9(SDC)氧离子导体材料, 对燃烧合成粉体的物相和显微形态进行了表征, 并研究了燃烧法合成SDC的烧结性能以及烧结体的导电性能. 研究结果表明, 采用尿素燃烧法合成SDC具有简便高效和合成粉体烧结活性高的优点. 经过燃烧过程后即可得到立方萤石结构的纯相SDC粉体, 合成粉体的分散性良好, 为50~150 nm的球形颗粒, 具有高的烧结活性, 在1250 ℃的烧结温度下, 陶瓷样品的相对密度可达到95.1%. 在600和800 ℃的测试温度下, 烧结温度为1250 ℃的陶瓷样品的电导率分别达到5.4×10-2和1.0×10-1 Ω-1·cm-1.     

Ce1－xNdxO2－δ固溶体的电子顺磁共振谱和阻抗谱的研究

利用溶胶-凝胶方法在800 ℃焙烧10 h后, 合成了固溶体Ce_1－xNd_xO_2－δ (x＝0.05～0.55), X射线衍射(XRD)测试表明固溶体已经形成立方萤石结构; 电子顺磁共振谱(EPR)研究表明在固溶体Ce_1－xNd_xO_2－δ中随着掺杂量x的增大, Ce^3＋离子含量减少, 说明掺杂Nd^3＋离子可以抑制Ce^4＋的还原; 交流阻抗谱的测量表明固溶体Ce_0.9Nd_0.1O_2－d 具有离子导电特性, 600和700 ℃时的电导率分别为4.25×10^－3和1.12×10^－2 S•cm^－1, 活化能为0.68 eV.     

固-溶法制备中温固体氧化物燃料电池高性能La0.8Sr0.2MnO3-Ba0.5Sr0.5Co0.8Fe0.2O3阴极

研究了新型固溶法合成La_0.8Sr_0.2MnO₃（LSM）包覆Ba_0.5Sr_0.5Co_0.8Fe_0.2O₃（BSCF）复合粉体（LSM-BSCF）,并探讨了其作为中温固体氧化物燃料电池阴极材料的电化学性能。LSM-BSCF阴极结合了LSM和BSCF阴极的优点,不仅增大了三相界面,而且稳定了微观结构。当温度为600-750℃时,其极化阻抗为0.61-0.09 Ω·cm²。与溶液注入法制备的高性能电极相比,极大地提高了性能稳定性。     

新型阴极材料Ba0.5Sr0.5Co0.8Fe0.2O3-σ制备与性能研究

Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-σ(BSCF), a new cathode material for solid oxide fuel cell (SOFC), was synthesized by polyacrylicacid (PAA) method. The lattice structures of samples calcined at different temperatures were characte-rized by XRD. Shrinkage, porosity and pore size of the porous BSCF as a function of sintering temperature were investigated. It was found that the cubic perovskite structure could be formed after calcination at 800 ℃ for 2 h, but not well crystallized as seen from some unknown phases, and the pure cubic perovskite structure was formed after calcination at 1 150 ℃ for 2 h. The particle size of BSCF was less than 1～2 μm. The shrinkage of the porous BSCF increased with sintering temperature, but the opposite was true for the porosity. After sintering at 1 100 ℃ for 4 h, the porous BSCF was still in an appropriate structure, with porosity of 29% and electrical conductivity above 400 S·cm^-1.     

SrCe0.95Er0.05O3-α固体电解质的导电性

SrCe_0.95Er_0.05O_3-α ceramic of a single orthorhombic phase of perovskite-type SrCeO₃ was prepared by high-temperature solid state reaction. Using the ceramic as solid electrolyte and porous platinum as electrodes, the measurements of conductivities and ionic transport numbers on SrCe_0.95Er_0.05O_3-α ceramic were performed by using electrochemical methods in the temperature range of 600～1 000 ℃ in wet hydrogen, dry air and wet air, respectively. The results indicate that the sample is a pure protonic conductor with a maximal conductivity of 0.01 S·cm^-1 in wet hydrogen, a mixed conductor of oxide-ion and hole in dry air, and a mixed conductor of proton, oxide-ion and hole in wet air.     

梯度材料LiNi0.8Co0.2O2的合成与表征

The gradient composite LiNi_0.8Co_0.2O₂ was synthesized using spherical Ni(OH)₂ particle coated by a sol-gel containing cobalt and lithium. The precursor was examined by DSC-TG. The gradient composite was characterized by SEM, EDS, XPS, XRD and ICP-AES. The XPS, EDS and ICP-AES results show that content of cobalt in the surface is higher than in the center of the spherical particle of the gradient composite. The first discharge specific capacity of the gradient composite sintered at 700 ℃ is 187.3 mAh·g^-1.     

溶胶凝胶法制备Nd2O3改性钛酸钡陶瓷的研究

The technological condition for the preparation of BaTiO₃ ceramics doped with Nd₂O₃ by Sol-Gel was deter-mined through orthogonal experiment. When n_Ba(Ac)2∶n_Ti(OC4H9)4∶n_Nd2O3∶n_{CH3(CH2)2CH2OH}∶n_H2O=1.00∶1.00∶0.003∶7.30∶37.04, pH=3.5,T=25℃,the light-yellow-transparent-stable solution and thorough transparent gel was generat-ed, the transforming time of solution to gel was 25h. The crystal structure and particle size of BaTiO₃ ceramics doped with Nd₂O₃ were studied by SEM and X-ray respectively, the type of the crystal was tetragonal, the particle size was about 24.7nm. The dielectric constant (ε) and dielectric loss (tanδ) of BaTiO₃ ceramics doped with Nd₂O₃ were determined between 10⁴～10⁶Hz, and the results showed that the dielectric constant was increased obviously, the dielectric loss was decreased clear and the resistivity (ρ_V) was also decreased noticeably.     

NH4PO3-SiO2复合电解质的溶胶凝胶法制备和导电性能

用溶胶凝胶法制备了复合固体电解质xNH₄PO₃-SiO₂(x=1，2，4)，并研究了该电解质在125～250 ℃范围内的导电性能。复合电解质的相结构分析表明，NH₄PO₃和SiO₂在溶胶凝胶法制备过程中没有发生化学反应;复合电解质的电导率随着NH₄PO₃含量增大而提高，并与NH₄PO     

氧离子导体La1.9Ba0.1Mo2O9-α的合成及其电性能研究

通过固相法合成了La_1.9Ba_0.1Mo₂O_9-α氧离子导体,对样品进行了XRD、SEM表征,采用交流阻抗谱、氧浓差电池、氧泵等电化学方法研究了该陶瓷样品在600～1 000 ℃下的离子导电特性。结果表明,该陶瓷样品在氧化性气氛中是纯的氧离子导体,1 000 ℃时的氧离子电导率达到0.09 S·cm^-1,高于母体La₂Mo₂O₉的氧离子电导率。本文还研究了样品的燃料电池性能,在1 000 ℃时氢气/氧气燃料电池的最大输出电流密度为280 mA·cm^-2,最大输出功率密度为112 mW·cm^-2。     

BaCe0.8-xNbxGd0.2O3-δ(0≤x≤0.45)的制备及性能研究

采用高温固相反应法制备了质子导体BaCe_0.8-xNb_xGd_0.2O_3-δ(0≤x≤0.45)。结合XRD、SEM、EIS等技术对其物相、微观形貌、稳定性及电导率进行了研究。结果表明,在1 600 ℃烧结5 h制备的质子导体BaCe_0.8-xNb_xGd_0.2O_3-δ(0≤x≤0.45)均能保持主相为斜方晶的钙钛矿结构。Nb的加入可明显提高烧结样品的致密性及在CO₂和水蒸气气氛下的稳定性。在湿润H₂/Ar(0.4%,V/V)气氛中800 ℃下,x=0.1样品的电导率为5.73 mS·cm^-1,电导活化能为0.35 eV,与x=0的样品相当。