乙醇在Ni-ZnO-ZrO2-YSZ阳极SOFC上的发电性能

为考察乙醇用于固体氧化物燃料电池的可行性,用柠檬酸溶胶 凝胶制备阳极催化材料Ni-ZnO-ZrO₂,利用机械混合法制备Ni-ZnO-ZrO₂-YSZ(Y₂O₃稳定的ZrO₂)阳极。用涂覆法,在YSZ电解质上,制备了Ni-ZnO-ZrO₂-YSZ/YSZ/LSM（La_0.85Sr_0.15MnO₃）与Ni-YSZ/YSZ/LSM的单体电池。在不同蒸发器操作温度、电池操作温度和乙醇蒸气流量下,以乙醇为燃料进行发电实验,对两种阳极的电池发电性能进行比较。实验结束后,用SEM检测了两种电池阳极的表面。结果表明,Ni-ZnO-ZrO₂-YSZ阳极SOFC的电池输出性能明显高于Ni-YSZ阳极,且Ni-ZnO-ZrO₂-YSZ阳极具有较好的抗积炭能力。     

低浓度干甲烷在SOFC Ni-YSZ阳极上的反应

向Ni-YSZ/YSZ/LSM(Ni-Y2O3稳定的ZrO/YSZ/La0.85Sr0.15MnO3-δ)电池阳极通入不同浓度的干甲烷,利用气相色谱对阳极尾气进行原位检测,研究在不同电流密度下,干甲烷在Ni-YSZ阳极上所发生的反应.通过理论开路电压和实测开路电压的比较、阳极尾气的定量分析以及CH4在Ni基阳极上基元反...     

共压直接成型法制备单腔体固体氧化物燃料电池

采用共压直接成型法制备单腔体固体氧化物燃料电池(SC-SOFC),单电池结构为Ni-YSZ/YSZ/LSM,YSZ为8%(x)Y2O3稳定的ZrO2,LSM为锰酸镧锶(La0.7Sr0.3MnO3).应用扫描电子显微镜(SEM)研究了电池微观结构,结果表明:阴极和电解质之间结合紧密,LSM在阴极YSZ三维骨架上负载性能良好;YSZ电解质薄膜厚约50μm,阳极厚约600μm,阴极层厚约100μm.研究了单电池反应温度T,阴极催化剂负载层数n,甲烷和氧气混合体积比Rmix对电池输出性能的影响规律.在T=800℃、n=2、Rmix=2时,电池性能达到最佳,开路电压为0.95V,最大电流密度为130mA·cm-2,最大功率密度为30mW·cm-2.     

薄膜型中温固体氧化物燃料电池 (SOFC)研制及性能考察

用一种廉价的湿化学方法 ,在Ni_YSZ阳极基膜上制备出致密的YttriaStabilizedZirconia(YSZ)薄膜 .薄膜的厚度约为 10 μm ,致密均匀 ,无裂纹等缺陷 .以Ni_YSZ阳极基膜 ,YSZ薄膜和锶掺杂锰酸镧阴极 (LSM )组装的SOFC单电池 ,在 80 0℃下功率密度达 0 1W /cm2 .研究分析表明 ,YSZ薄膜的IR降 (包括电极 /YSZ薄膜的接触电阻 )较小 ,不是影响电池性能的主要因素 ,大的阳极过电位是影响电池性能的主要因素 .     

直接甲烷固体氧化物燃料电池Ni-BZCYYb阳极抗积炭性能研究

直接以甲烷(CH₄)为燃料的固体氧化物燃料电池(Solid Oxide Fuel Cell,SOFC)具有操作系统简单、发电效率高、环境友好等优点,但传统镍基阳极使用CH₄时极易产生积炭,导致电池性能下降甚至破裂。因此,如何有效抑制积炭的产生是目前镍基阳极面临的重要挑战。本文针对传统Ni-Y_0.08Zr_0.92O_2-δ(Ni-YSZ)阳极使用CH₄时存在严重的积炭行为,采用质子导体Ba Zr_0.1Ce_0.7Y_0.1Yb_0.1O_3-δ(BZCYYb)代替氧离子导体YSZ,考查了Ni-BZCYYb对CH₄水蒸气重整反应的催化活性和抗积炭性能,同时与Ni-YSZ进行比较。以Ni-BZCYYb为阳极的SOFC,在700–600℃、湿CH₄(97%CH₄-3%H₂O)为燃...     

Cu-CeO_2基阳极直接甲烷SOFC的制备及其性能

采用干压法制备了NiO-YSZ(氧化钇稳定氧化锆)/(ZrO2)0.89(Sc2O3)0.1(CeO2)0.01(10ScSZ-1CeO2)半电池,经还原-酸溶法除去NiO制备了多孔YSZ负载致密10ScSZ-1CeO2双层结构,通过浸渍法在多孔YSZ阳极基体中引入Ce、Cu的硝酸盐制备Cu-CeO2-YSZ复合阳极,结合La0.6Sr0.4Co0.2Fe0.8O3-δ(LSCF)阴极构建了Cu-CeO2-YSZ/10ScSZ-1CeO2/LSCF单元电池.通过X射线衍射(XRD)和场发射扫描电镜(FESEM)等手段对电池单元的物相、微观结构进行表征.结果表明:还原-酸溶法制备的YSZ/10ScSZ-1CeO2双层结构的YSZ基体具有孔隙率高(64%)、孔洞连通性好的微观结构,有助于采用浸渍法引入Ce、Cu硝酸盐;10ScSZ-1CeO2电解质薄膜致密无缺陷,厚约30μm.电性能测试表明所构建单元固体氧化物燃料电池(SOFC)具有良好的电性能输出,在650℃以湿H2和CH4为燃料时的最大功率密度分别为0.29和0.09W·cm-2;在700℃以湿H2和CH4为燃料时的最大功率密度分别达到0.48和0.21W·cm-2.优良的电性能主要归功于小的电解质内阻和阴极极化电阻以及良好的阳极微观结构.     

纳米La0.6Sr0.4Co0.2Fe0.8O3-δ阴极粉体的溶液燃烧法合成与性能表征

采用硝酸盐-甘氨酸溶液燃烧法合成了La0.6Sr0.4Co0.2Fe0.8O3-?啄(LSCF)前驱粉体, 通过XRD、BET、FESEM及激光粒度仪等手段对粉体进行表征. 结果表明, 所合成的LSCF粉体为纯钙钛矿结构, 具有高达22.9 m2·g-1的比表面积, 粒度均匀, 平均颗粒尺寸为175 nm. 非等温烧结实验表明该粉体具有良好的低温烧结活性. 在阳极NiO-YSZ(氧化钇稳定氧化锆)负载的电解质YSZ上, 于800 ℃烧结制备LSCF阴极组成的单元电池Ni-YSZ/YSZ/LSCF, 在700 ℃下以H2作燃料时具有良好的电池性能, 最大功率密度为0.97 W·cm-2, 在0.7 V时的功率密度约达到0.83 W·cm-2. 这种无中间缓冲层的低温制备LSCF阴极方法, 简化了电池结构及其制备过程, 同时提高了电池的性能.     

Cu-CeO2基阳极直接甲烷SOFC的制备及其性能

采用干压法制备了NiO-YSZ(氧化钇稳定氧化锆)/(ZrO2)0.89(Sc2O3)0.1(CeO2)0.01(10ScSZ-1CeO2)半电池, 经还原-酸溶法除去NiO制备了多孔YSZ负载致密10ScSZ-1CeO2双层结构, 通过浸渍法在多孔YSZ阳极基体中引入Ce、Cu的硝酸盐制备Cu-CeO2-YSZ复合阳极, 结合La0.6Sr0.4Co0.2Fe0.8O3-δ(LSCF)阴极构建了Cu-CeO2-YSZ/10ScSZ-1CeO2/LSCF单元电池. 通过X射线衍射(XRD)和场发射扫描电镜(FESEM)等手段对电池单元的物相、微观结构进行表征. 结果表明: 还原-酸溶法制备的YSZ/10ScSZ-1CeO2双层结构的YSZ基体具有孔隙率高(>64%)、孔洞连通性好的微观结构, 有助于采用浸渍法引入Ce、Cu硝酸盐; 10ScSZ-1CeO2电解质薄膜致密无缺陷, 厚约30 μm. 电性能测试表明所构建单元固体氧化物燃料电池(SOFC)具有良好的电性能输出, 在650 ℃以湿H2和CH4为燃料时的最大功率密度分别为0.29和0.09 W·cm-2; 在700 ℃以湿H2和CH4为燃料时的最大功率密度分别达到0.48 和0.21 W·cm-2. 优良的电性能主要归功于小的电解质内阻和阴极极化电阻以及良好的阳极微观结构.     

梯度Cu-CeO2-Ni-YSZ复合阳极直接甲烷SOFC的制备与性能

采用三层共压-共烧结法, 并涂覆La_0.8Sr_0.2MnO₃ (LSM)阴极, 制备了梯度Ni-YSZ阳极结构的固体氧化物燃料电池(SOFC)(大孔Ni-YSZ|微孔Ni-YSZ|YSZ|LSM) (YSZ: Y₂O₃稳定的ZrO₂; LSM: Sr 掺杂的LaMnO₃).通过浸渍法在大孔Ni-YSZ 基底中沉积占总重量约1%的Cu-CeO₂抗积碳催化剂, 形成梯度Cu-CeO₂-Ni-YSZ复合阳极. 分别以CH₄和H₂为燃料, 空气为氧化剂, 测定了构造的SOFC输出电性能和长期稳定性. 结果表明,三层共压-共烧结法制备的梯度阳极SOFC, 层间结合紧密无缺陷, 阳极梯度孔结构明显, YSZ膜致密无缺陷.在850℃下操作, 以梯度Ni-YSZ 阳极制备的SOFC, 燃料由H₂切换为甲烷时, 最大功率密度由284 mW·cm^-2下降到143 mW·cm^-2; 而以Cu-CeO₂-Ni-YSZ 复合阳极构造的SOFC出现相反趋势, H₂切换为甲烷后最大输出由176 mW·cm^-2增加到196 mW·cm^-2. 在250 mA·cm^-2负荷下, 梯度Ni-YSZ阳极支撑的直接甲烷SOFC仅稳定运转10 h 便出现明显衰减, 阳极中积碳严重; 但Cu-CeO₂-Ni-YSZ 复合阳极支撑SOFC连续运转50 h, 输出电压与输出功率密度基本不变, 电镜观察不到积碳.     

硬模板法制备固体氧化物燃料电池Ni_(0.5)Cu_(0.5)Ba_(0.05)O_x包覆管状SDC立体阳极

为在固体氧化物燃料电池中有效利用干甲烷为燃料,需制作多孔立体阳极。采用硬模板法和浸渍法制备Ni_(0.5)Cu_(0.5)Ba_(0.05)O_x包覆管状SDC阳极材料(Ni_(0.5)Cu_(0.5)Ba_(0.05)O_x/SDC),为作对比,用溶胶凝胶法制备粉末状Ni_(0.5)Cu_(0.5)Ba_(0.05)O_x,机械混合SDC粉末制备Ni_(0.5)Cu_(0.5)Ba_(0.05)O_x-SDC。将这两种阳极材料分别制作电解质支撑的单电池Ni_(0.5)Cu_(0.5)Ba_(0.05)O_x/SDC|YSZ|LSMYSZ与Ni_(0.5)Cu_(0.5)Ba_(0.05)O_x-SDC|YSZ|LSM-YSZ,并进行发电性能测试以及长期稳定性实验。结果表明,800℃下,干甲烷环境中,Ni_(0.5)Cu_(0.5)Ba_(0.05)O_x-SDC为阳极的单电池最大功率密度为324.99 m W/cm2,运行10 h后,电压下降5.60%;而以Ni_(0.5)Cu_(0.5)Ba_(0.05)O_x/SDC为阳极的单电池最大功率密度达到384.54 m W/cm2,运行100 h后,电压未严重衰减。实验后阳极的SEM照片表明,Ni_(0.5)Cu_(0.5)Ba_(0.05)O_x-SDC阳极内孔隙狭小,易被积炭堵塞;而Ni_(0.5)Cu_(0.5)Ba_(0.05)O_x/SDC阳极呈立体多孔结构,有利于燃料气体与反应后气体的扩散。催化剂颗粒均匀地包覆在SDC纤维管表面,有利于增加三相界面,提高电池的稳定性。     

锰酸镧双层复合电极的制备和性能的研究

固体氧化物燃料电池（ Solid Oxide Fuel Cell, SOFC）是一种很有希望的新型能源转换系统 .它具有能量转换效率高、可利用燃料范围广、低排放等普通热机所无法比拟的优点,已倍受人们的关注 .　　锶掺杂的锰酸镧（ La1－ xSrxMnO3, LSM）由于具有高的电子导电性和对氧还原的良好的电催化活性,以及它和钇稳定的氧化锆（ YSZ）都有良好的热稳定性和化学稳定性,因此是目前广泛使用的阴极材料 .以 YSZ为固体电解质的固体氧化物燃料电池的一个主要缺点是操作温度太高（约为 1273 K）,如果把电池的操作温度降低到 873－ 1073 K,则…     

Crafting La0.2Sr0.8MnO3-δ membrane with dense surface from porous YSZ tube

This work reports a new design of asymmetric tubular oxygen-permeable ceramic membrane (OPCM) consisting of a porous Y₂O₃ stabilized ZrO₂ (YSZ) tube (with ∼1 μm of pore diameters and 31% porosity) as the support and a gas-tight mixed conductive membrane. The membrane has an interlocking structure composed of a host matrix, Ag(Pd) alloy (9:1 by wt) doped perovskite-type (LSM80, 90wt%), and the embedded constituent, pristine LSM80. The Ag(Pd) alloy component promotes not only electronic conductivity and mechanical strength but also reduction of both porosity and pore sizes in the layer (∼10-μm-thick) where it dopes. The porous structure in this layer could then be closed through a solution coating procedure by which ingress of an aqueous solution containing stoichiometric nitrate salts of La³⁺, Mn³⁺, and Sr²⁺ to the pore channels takes place first and the mixture of nitrate salts left after drying is subjected to pyrolysis to generate tri-metal oxides in situ. This is followed by calcinations at l,300 °C to consolidate the embedded trioxide and to cohere them with the Ag(Pd)-LSM80 host matrix. The structure formed is dubbed LSM80(S)-Ag(Pd)-LSM80, which was confirmed gas-tight by electron micrograph and N₂ permeation test. Finally, we assess the chemical compatibility between LSM80 and YSZ at the sintering temperature by X-ray diffraction and electrochemical impedance analysis. The oxygen permeation of the fabricated LSM80(S)-Ag(Pd)-LSM80-YSZ membrane is within the temperature range of 600 to 900 °C. The tests reveal good compatibility between the LSM80 and YSZ and a reasonably high oxygen permeation flux in association with this OPCM assembly.     

Lanthanum strontium manganite/yttria-stabilized zirconia nanocomposites derived from a surfactant assisted,co-assembled mesoporous phase

A one-pot, soft-chemistry, surfactant-assisted co-assembly approach to prepare La(1-x)Sr(x)MnO(3) (LSM)/Y(2)O(3)-stabilized ZrO(2) (YSZ) nanocomposites for use as solid oxide fuel cell (SOFC) cathodes has been investigated. This material with sub-hundred nanometer grain sizes for each phase is the first such nanocomposite where aqueous-based precursors of each component are incorporated in a single synthetic step. This approach utilizes the co-assembly of an anionic yttrium/zirconium acetatoglycolate gel, cetyltrimethylammonium bromide as the cationic surfactant template, and inorganic La, Mn, and Sr salts under alkaline aqueous conditions. The resulting as-synthesized product is an amorphous mesostructured organic/inorganic composite, which is transformed to a mesoporous inorganic oxide with nanocrystalline YSZ walls upon calcination. Calcination to temperatures above 600 degrees C lead to collapse of the mesopores followed by further crystallization of the nanocrystalline YSZ phase and a final crystallization of the LSM perovskite phase above 1000 degrees C. Both the fully crystalline LSM/YSZ and the mesoporous intermediate phase have been investigated for phase homogeneity by TEM energy-dispersive X-ray spectroscopy (EDX) mapping and spot analysis which confirm the dispersion of LSM within a YSZ matrix at the nanometer scale. Impedance spectroscopy analysis of LSM/YSZ nanocomposite electrodes demonstrate a low polarization resistance of around 0.2 omega cm(2) with an activation energy (E(a)) as low as 1.42 eV. Cathodic polarization studies show stable current densities over a 40 h test demonstration.     

High performance solid oxide fuel cells with electrocatalytically enhanced (La,Sr)MnO3 cathodes

The conventionally mixed LSM–YSZ, LSM impregnated YSZ (LSM + YSZ) and Pd impregnated LSM–YSZ (Pd + LSM–YSZ) cathodes, were prepared and evaluated by electrochemical impedance spectroscopy and single cell testing. The electrochemical performance of the impregnated cathodes have been significantly boosted due to the formation of nano-sized LSM and Pd particles on the YSZ and LSM–YSZ substrates, respectively, and in turn, the increased area of the triple phase boundary (TPB) where the O₂ reduction reaction occurs, the power densities as high as 1.42 and 0.83 W cm^?2 at 750 °C were achieved from single cells with the Pd + LSM–YSZ and LSM + YSZ cathodes, respectively, in contrast to 0.20 W cm^?2 from the single cell with the conventional LSM–YSZ cathode. Suggesting the Pd + LSM–YSZ and LSM + YSZ cathodes can be well used for the intermediate temperature solid oxide fuel cells (IT-SOFCs).     

Electrocatalytic properties of La0.9Sr0.1MnO3-based electrodes for oxygen reduction

Electrochemical reduction of oxygen at the interface between a La_0.9Sr_0.1MnO₃ (LSM)-based electrode and an electrolyte, either yttria-stabilized-zirconia (YSZ) or La_0.8Sr_0.2Ga_0.9Mg_0.1O₃ (LSGM), has been investigated using DC polarization, impedance spectroscopy, and potential step methods at temperatures from 1053 to 1173 K. Results show that the mechanism of oxygen reduction at an LSM/electrolyte interface changes with the type of electrolyte. At an LSM/YSZ interface, the apparent cathodic charge transfer coefficient is about 1 at high temperatures, implying that the rate-determining step (r.d.s.) is the diffusion of partially reduced oxygen species, while at an LSM/LSGM interface the cathodic charge transfer coefficient is about 0.5, implying that the r.d.s. is the donation of electrons to atomic oxygen. The relaxation behavior of the LSM/electrolyte interfaces displays an even more dramatic dependence on the type of electrolyte. Under cathodic polarization, the current passing through an LSM/YSZ interface increases with time whereas that through an LSM/LSGM interface decreases with time, further confirming that it is the triple phase boundaries (TPBs), rather than the surface of the LSM or the LSM/gas interface, that dominate the electrode kinetics when LSM is used as an electrode. Electronic Publication     

锰酸镧和氧化钇稳定的氧化锆复合阴极的研究

用交流阻抗,强极化和电导测量等方法考察了一系列不同氧化钇稳定氧化锆(YSZ)含量的锶掺杂锰酸镧(LSM)复合阴极的电化学性能,发现随着掺入YSZ量的增大,阴极性能大幅度提高,当YSZ质量分数为40%时,电极性能最好,电化学极化电阻约为1.18Ω/cm².通过分析发现,YSZ的掺杂使电极反应过程的控制步骤发生了变化.同时发现,随着YSZ含量的增加,电极的接触电阻增大.以Pt为电流收集层和40%的YSZ+LSM的复合电极形成的二层电极可有效地消除接触电阻,进一步提高了复合电极的性能.在1223K极化电阻从1.18Ω/cm²下降到0.41Ω/cm².     

Electrical conductivities and microstructures of LSM,LSM-YSZ and LSM-YSZ/LSM cathodes fabricated on YSZ electrolyte hollow fibres by dip-coating

Lanthanum strontium manganite – La_0.80Sr_0.20MnO₃ (LSM), LSM-Yttria stabilised zirconia (LSM-YSZ) composite and LSM-YSZ/LSM double-layer cathodes were separately fabricated on Yttria stabilised zirconia (YSZ) electrolyte hollow fibres by dip coating; their electrical conductivities and microstructures were then determined by the direct current four-probe method and scanning electron microscopy (SEM), respectively. Excellent cathode-electrolyte and cathode-cathode adhesion without delamination were achieved by the dip-coating fabrication method. The apparent electrical conductivities of porous LSM, LSM-YSZ and LSM-YSZ/LSM cathodes manufactured on YSZ hollow fibre by dip-coating and sintered at various temperatures in the range 1273–1473 K for 3 h, were 1.8 × 10³–5.5 × 10³ S/m, 0.32–209 S/m and 1.3 × 10³–5.5 × 10³ S/m, respectively, at measurement temperatures of 673–1073 K. The operating temperature dependence of the apparent electrical conductivity of the LSM, LSM-YSZ and LSM-YSZ/LSM cathodes was defined by the Arrhenius equation for electrical conductivity. The activation energies for electrical conductivity were derived as 0.106–0.147 eV, 0.83–0.94 eV, and 0.104–0.146 eV for the LSM, LSM-YSZ and LSM-YSZ/LSM cathodes, respectively. The LSM-YSZ and LSM-YSZ/LSM cathodes were strongly influenced by the YSZ and LSM phases, respectively.