不锈钢粉末与丝网烧结多孔材料高温硫化性能研究

为了考察滤材结构和形貌对材料抗高温硫化性能影响,研究了不锈钢316L、310S粉末与丝网烧结多孔材料在高温硫化氢气氛[350℃,介质:CO2+H2S(0.02％,体积分数)]中的硫化性能以及材料孔结构的稳定性,并利用光学显微镜观察表面形貌,从而评价耐蚀性能.结果表明:经过1 500h试验,316L、310S粉末烧结金属多孔材料在高温硫化氢气氛中耐腐蚀性能明显低于同类丝网材料,粉末与丝网烧结金属多孔材料的耐蚀性能差异主要由滤材结构和其比表面积决定.     

SOFC金属连接体材料的高温氧化和导电性能

以固体氧化物燃料电池(SOFC)金属连接体为研究对象,分析了SUS 430铁素体不锈钢和Haynes 230合金在阴极气氛(空气)中模拟SOFC的高温氧化行为.利用薄膜X射线衍射技术研究了合金氧化物的相组成及演化过程,通过扫描电镜观察分析了合金氧化物表面的微观形貌和厚度.结果表明,两种合金的表面均形成了多层氧化物,它们依次为基体/Cr2O3/MnCr2O4尖晶石相.两种氧化物相分别形成于不同的氧化动力学阶段.氧化动力学外推和氧化物面比电阻估算结果表明,两种合金的高温氧化和导电性能均可满足作为SOFC金属连接体的使用要求.     

真空烧结条件对钽粉物理性能的影响

研究了不同的真空烧结条件对钠还原制备钽粉的比表面积、表面微观形貌的影响。通过拟合得到不同比表面积钽粉的初始烧结温度、比表面积随真空烧结温度变化的经验方程,以及钽粉经高温烧结后比表面积变化拟合关系式。当在初始烧结温度以下进行烧结时,粉末的比表面积、微观形貌没有较大变化,当烧结温度高于初始烧结温度时,粉末的比表面积随真空烧结温度增加而减少,而粉末形貌表现为细枝晶粗大化。     

TiO_2包覆层结晶度对染料敏化太阳能电池性能的影响

二氧化钛(TiO_2)纳米颗粒广泛应用于染料敏化太阳能电池的光阳极。设计了一种以TiO_2纳米颗粒包覆Ag纳米线阵列的异质结作为光阳极的新型结构的染料敏化太阳能电池。通过控制水热反应温度制备了两种具有不同结晶度的TiO_2纳米颗粒包覆层,利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射分析(XRD)对包覆层的形貌和晶体结构进行了表征,通过I-V曲线和紫外光电子能谱(UPS)分析了TiO_2包覆层的结晶度对电池性能的影响。结果表明:TiO_2包覆层的结晶度对组装后的电池效率具有显著影响,TiO_2结晶度较低的电池具有较高的开路电压(Voc),结晶度较高的电池具有较大的短路电流密度(Jsc)。理论分析表明:电池开路电压的差异来源于TiO_2包覆层结晶度不同导致的电子结构的变化;而短路电流密度的差异则是由光阳极表面积大小和电子从染料激发态向TiO_2导带注入效率不同造成的。     

直接甲醇燃料电池膜电极稳定性的研究

直接甲醇燃料电池(DMFC)运行过程中膜电极的稳定性是其商业化的关键问题之一。采用加热喷雾法制备膜电极并对其稳定性进行研究。结果表明,膜电极的电池性能经过连续极化后略有下降,但下降幅度不大,电压衰减速率仅1.0mV/h左右;经过25h恒电流放电,欧姆阻抗和传质阻抗都呈上升趋势,说明电池的欧姆极化损失加大、传质阻力上升。SEM测试结果表明,经过长时间恒电流放电后,膜电极催化层与电解质膜、扩散层及催化层等之间发生剥离,造成传质阻力上升和膜电极结构破坏,使电池性能衰退。循环伏安测试结果表明,经长时间放电运行后,阳极和阴极的氢脱附峰的积分面积减小,说明膜电极阴阳极催化层的电化学活性表面积降低。     

Li_2CO_3对锂氧化物电极SOFC电化学性能影响研究

本文利用机械混合的方式将SrTiO_3与Li_2CO_3按照不同质量比混合制成了比例分别为95/5,90/10,70/30及100/0的STO-x%Li_2CO_3(x=0,5,10和30)复合电解质,并制备了结构为泡沫镍-Ni_(0.8)Co_(0.15)Al_(0.05)LiO_2(NCAL)/STO-x%Li_2CO_3/NCAL-泡沫镍的单电池。在550℃、H_2/Air气氛中的燃料电池性能测试结果显示在SrTiO_3电解质中以机械混合的方式加入Li_2CO_3后电池的最大功率密度随着碳酸锂的添加量增加而降低,而且在电解质中没有混合Li_2CO_3的SrTiO_3电解质电池取得了最高的最大输功率密度,说明以机械混合的方式在SrTiO_3电解质中加入Li_2CO_3对这种新型结构SOFC的电化学性能没有提升作用。Ni-NCAL阳极在电化学性能测试过程中被还原生成的Li_2CO_3扩散到SrTiO_3电解质中形成的非晶层包覆在电解质颗粒表面对电解质离子电导率提升起到了关键作用。     

直接天然气火焰燃料电池阳极抗积碳的研究

采用流延法制备了阳极支撑型固体氧化物燃料电池(SOFC)。并通过浸渍法，在Ni-YSZ阳极表面制备了Ag-Sm₂O₃复合催化功能层。通过扫描电镜(SEM)和X射线衍射(XRD)测试分析，发现Ni-YSZ阳极表面的Ag-Sm₂O₃催化功能层由纳米Ag-Sm₂O₃颗粒构成，纳米颗粒大小为几十纳米。该催化功能层和Ni-YSZ阳极构成了Ag-Sm₂O₃/Ni-YSZ复合阳极。在700～800℃温度范围内，以主要成分为CH₄的天然气为燃料，对电池片进行电化学测试。通过调整天然气流量，测试了电池片在700,750和800℃下的电化学性能。750℃时，浸渍了6.6×10^-3 g催化剂的阳极电池的峰值功率密度达到320 mW·cm^-2，比未浸渍催化剂的电池提高了一倍。电池片运行40 h后，电池性能未出现明显衰减，阳极表面无明显积碳。Ag-Sm₂     

气氛控制烧结制备17M/(10NiO-NiFe2O4)金属陶瓷的抗氧化性能研究

采用等温热重法,测试了冷压-烧结和气氛控制烧结两种方法制备的17M/(10NiO-NiFe2O4)(M=Cu和Ni)金属陶瓷惰性阳极的高温抗氧化性能。考察了氧化温度和氧化时间对17M/(10NiO-NiFe2O4)金属陶瓷氧化行为的影响,并对其氧化产物层微观结构进行了分析。结果表明,气氛控制烧结有利于提高金属陶瓷材料的抗氧化性,表面的致密氧化层能够有效阻挡氧的向内扩散。17Cu/(10NiO-NiFe2O4)金属陶瓷材料表面氧化层中的Cu的质量分数占到37.58%比过渡层中11.28%高,说明Cu有向表面迁移后再氧化的现象。     

铝棒低银铅合金表面陶瓷化复合阳极的制备与性能

为获得一种锌电积用低成本、低析氧电位和高催化活性的阳极,在铝棒表面通过挤压复合技术包覆Pb-0.2% Ag合金得到Al棒Pb-0.2% Ag阳极.在含氟的硫酸溶液中,通过阳极氧化在Pb-0.2% Ag合金和Al棒Pb-0.2% Ag合金阳极表面形成具有高催化性能的膜层,采用显微图像分析仪和数显显微硬度计表征了膜层的厚度及硬度,并通过电子拉伸试验对比了两种阳极的极限抗拉强度.采用X射线衍射、扫描电子显微镜、循环伏安法、阳极极化和交流阻抗法等技术手段研究了Al棒Pb-0.2% Ag与Pb-0.2% Ag阳极表面氧化膜层的物相、形貌以及电化学性能.结果表明:Al棒Pb-0.2% Ag阳极相比Pb-0.2% Ag阳极表面易生成致密较厚的氧化膜层,且膜层硬度提升了41.64%,其氧化膜层主要物相均为电催化活性良好的β-PbO₂.新型阳极的极限抗拉强度是传统阳极的1.3倍,大大改善了阳极材料的机械性能.阳极极化曲线数据显示Al棒Pb-0.2% Ag/PbO₂阳极在电积锌体系中具有较低的析氧电位(1.35 V vs MSE,500 A·m-2)和较高的交换电流密度(7.079×10-5 A·m-2).循环伏安曲线和交流阻抗数据显示Al棒Pb-0.2% Ag/PbO₂阳极具有较高的电催化活性、较大的表面粗糙度和较小的电荷传质电阻.在电积锌实验中,栅栏型Al棒Pb-0.2% Ag/PbO₂阳极相比传统Pb-0.2% Ag阳极平均槽电压下降了75 mV,而且大大减少了阳极泥的产生.      

Al_2O_3电解质新型结构SOFC制备及性能研究

本文主要研究了以Al_2O_3为电解质的新型结构低温固体氧化物燃料电池。分别以三种不同结构的氧化铝(α-Al_2O_3、β-Al_2O_3和含有一定γ相的α-Al_2O_3)为电解质制备了结构为:泡沫镍-Ni_(0.8)Co_(0.15)Al_(0.05)LiO_2(NCAL)/Al_2O_3/NCAL-泡沫镍的SOFC,并在H_2燃料中测试了电化学性能。研究发现三种电池开路电压和最大输出功率密度都有明显差异。α-Al_2O_3、β-Al_2O_3和含有一定γ相的α-Al_2O_3电解质电池在550℃下H_2/air气氛中的开路电压分别为:1.057V、0.415V和0.945V;三种电池的最大功率密度分别为173.44mW·m~(-2)、3.76mW·m~(-2)和99.11mW·m~(-2)。交流阻抗谱结果显示α-Al_2O_3的离子电导率最高,为0.17S·cm~(-1)。通过Ce_(0.9)Gd_(0.1)O_2(GDC)/Al_2O_3双层电解质电池的离子过滤实验发现Al_2O_3电解质中的载流子包含氧离子。对不同结构Al_2O_3粉体材料及其在电池中电化学性能测试前后表面氧元素的结合能的XPS表征结果研究发现:不同结构的Al_2O_3的离子电导率大小跟其表面氧空位浓度有关,氧空位浓度越大,离子电导率越高。Al_2O_3的表面氧空位浓度在氢气通入后也会显著增加。界面氧离子传导应该是这种以氧化铝为电解质的新型结构SOFC的氧离子传导机理。     

固体氧化物燃料电池阳极材料La0.75Sr0.25Cr0.5Mn0.5O3-δ的合成及选择性研究

固体氧化物燃料电池（Solid oxide fuel cell, SOFC）是一种新型的清洁能源,而其阳极材料是固体氧化物燃料电池的最关键的部分,阳极材料的好坏会直接影响SOFC的性能.文中介绍了SOFC阳极材料La_0.75Sr_0.25Cr_0.5Mn_0.5O_3-δ（LSCM）的合成方法和性能表征.分别采用甘氨酸-燃烧法和柠檬酸溶胶-凝胶法合成La_0.75Sr_0.25Cr_0.5Mn_0.5O_3-δ（LSCM）,然后把合成的LSCM放在温度分别是800 ℃、900 ℃、1 000 ℃的马弗炉中进行高温烧结一定的时间,通过对产品进行XRD、SEM、电化学性能分析,得出了采用溶胶-凝胶法合成LSCM后,经1 000 ℃高温煅烧为较优的合成方法和实验条件.      

Effect of samarium doped ceria nanoparticles impregnation on the performance of anode supported SOFC with(Pr_(0.7)Ca_(0.3))_(0.9)MnO_(3-δ) cathode

Solid oxide fuel cell(SOFC) electrodes,after a high temperature sintering,may be impregnated to deposit nanoparticles within their pores to enhance the catalytic function.Samarium doped CeO2(SDC) nanoparticles were infiltrated into(Pr0.7Ca0.3)0.9MnO3-δ(PCM) cathode of anode supported SOFC cells.The cell with 2.6 mg/cm2 SDC impregnated in cathode showed the maximum power density of 580 mW/cm2 compared with 310 mW/cm2 of the cell without impregnation at 850 °C.The cells were also characterized with the impedance spectra,and the SDC impregnation significantly reduced the polarization resistance.After performance test the cells were characterized with scanning electron microscopy(SEM),and the cathode morphology showed the impregnated SDC particles were nanosized and were deposited on the surface of the PCM framework.The possible mechanism for the performance improvement was discussed.     

Application of Glass Sealant for SOFC

Glass and glass-ceramic materials were investigated as SOFC seals at 800 ～ 850 ℃. The material was based on the glass and glass-ceramic in the BaO-CaO-Al2O3-SiO2-La2O3-B2O3 system. The sealant has a minimum thermal expansion mismatch with yttria-stabilized zirconia (YSZ)electrolyte and Ni/gYSZ for the anode. The sealant has a superior stability during the process of operation in SOFC and can withstand thermal shock during the process of thermal cycling. The results show that the BaO-CaO-Al2O3-SiO2-La2O3-B2O3 system sealant can be used as sealing materials for SOFC.     

Development of metal supported solid oxide fuel cells based on powder metallurgical manufacturing route

Abstract

In the past few decades, stationary solid oxide fuel cell (SOFC) systems have been developed that can generate electricity and heat from the energy stored in hydrogen or hydrocarbons with total efficiencies up to 95%. While the mechanical cell support of stationary systems is commonly supplied by thick ceramic cell components (i.e. anode and electrolyte supported concepts), mobile systems demand a more robust design. This is ensured by a strong yet porous metallic substrate which serves as the mechanical backbone of thin film membrane electrode assemblies [metal supported cell (MSC) concept]. Porous PM Fe–Cr oxide dispersion strengthened alloys for use as MSC supports have recently been developed. These materials provide mechanical and chemical long term stability in typical SOFC atmospheres at operation temperatures up to 850°C. The substrates support a multilayer anode–electrolyte–cathode thin film assembly, constituting a high performance MSC repeat unit. These units are the building blocks for MSC stacks with superior properties for mobile applications.     

用涂布共烧结法制备固体氧化物燃料电池

以８％Ｙ２Ｏ３稳定的超细ＺｒＯＺ２（８ＹＳＺ）粉末为固体电解质材料，以喷雾热解法制备的超细Ｌａ０．８Ｓｒ１－ｘＭｎＯ３、（２０ＬＳＭ）粉末为空气极电极材料，以ＮｉＯ／８ＹＳＺ粉末为燃料电极原料，采用浆料涂层共烧结法制备电极薄膜，并组装了固体氧化物燃料电池（ＳＯＦＣ）。在Ｈ２－Ｎｉ－８ＹＳＺ－２０ＬＳＨ－Ａｉｒ体系中，分别测定了８００℃用１０００℃时的开路电压及电池Ⅰ—Ⅴ特性曲线。     

Cone-shaped cylindrical Ce_（0.9）Gd_（0.1）O_（1.95） electrolyte prepared by slip casting and its application to solid oxide fuel cells

A cone-shaped gadolinium doped ceria(Ce0.9Gd0.1O1.95,GDC) electrolyte cylinder with a thin wall was fabricated using slip cast-ing technique.The diameter of the larger open end of the cone-shaped cylinder was 0.85 cm,the length was 1.0 cm,and the thickness of the wall was 0.026 cm after sintering.Both the electrolyte and electrode powders were fabricated by using a glycine-nitrate process.A single solid oxide fuel cell(SOFC) was prepared with the cone-shaped electrolyte,NiO-GDC(70:30 wt.%) anode and Sm0.5Sr0.5CoO3(SSC) cathode.Its electrochemical performance(I-V curve) and electrochemical impedance spectroscopy(EIS) were studied with humidified hydrogen as the fuel and air as the oxidant.The maximum output power density was about 300 ?mW/cm2 at 700 oC.The EIS results showed that the dominant loss of the SOFC was from the ohmic resistance of the electrolyte.     

Status of Research on Application of High Purity Rare Earth Oxides in Solid Oxide Fuel Cells

The solid oxide fuel cell (SOFC) is a high-efficient and environmentally friendly power generation system.The rare earth oxide materials are used extensively in the manufacturing of SOFC components.In particular, the CeO2doped with Gd2O3 or Sm2O3, lanthanide perovskite oxides are indispensable and key materials for developing the intermediate temperature SOFC.The research and development status of application of high purity rare earth oxides in SOFC was overviewed.The rare earth oxide-based and -doped materials were discussed for the SOFC components.Concerning the rare earth oxides applicable to SOFC, several topics were also pointed out for further researching and developing.     

High Temperature Solid Oxide Fuel Cells(SOFC)

The history and the state of the art of solid oxide fuel cells(SOFC)is reviewed in this paper.Itdescribes mainly on the material selection,structure design and technological economics of SOFC.The appli-cation of great amount of rare earth materials in SOFC may well extend the market potential of rare earthmaterials in the world.A research project to be carried out as early as possible in China on the SOFC tech-nology will be far-reaching.     

溶胶-凝胶法在纳米La1-xMxCrO3粉料制备中的应用

掺杂二价碱土金属的铬酸镧是目前研究最深入和应用效果最好的固体氧化物燃料电池(SOFC)的连接材料,它几乎占整个SOFC制造成本的一半。制备工艺有固相法、溶胶-凝胶法、化学共沉淀法、联氨法和水热法等。本文综述了溶胶-凝胶法及用该方法制备La1-xMxCrO3(M=Sr,Ca)材料的现状。     

Modified room temperature solid-state synthesis of yttria-stabilized zirconia(YSZ) nano-powders for solid oxide fuel cells

High-performance solid oxide fuel cell(SOFC) is in urgent need of high-quality electrolyte powders with high reactivity and chemical uniformity.Here,8 mol% Y₂O₃ doped ZrO₂(YSZ) nano-powders were synthesized by an improved solid-state reaction method at ambient temperature,and were applied to the fabrication of SOFC electrolytes.YSZ nano-powders show average grain sizes of ～20 nm and high dispersibility,which is comparable with or even better than some other chemi...