Manufacturing and microstructure of porous metal supports for a solid oxide fuel cell

Abstract

One of the major drawbacks of a solid oxide fuel cell (SOFC) is the longtime stability. In order to have mechanical stability, the cell can be supported by a so-called porous metal support. These metal supports are usually manufactured by tape casting. This work, in contrast, is focused on processing these supports by different powder metallurgical techniques such as the press- and sinter route, gravity sintering or metal injection moulding. For some samples a shrinkage of 15% could be obtained as defined by the shrinkage of the ceramic functional layers (in case of desired “co-sintering an interval of 15–20% is preferable). The most promising manufacturing routes were found to be gravity sintering (about 50% porosity) and MIM (20–28% porosity): in both cases the pores are homogeneously distributed, and only slight agglomeration of pores can be seen.     

Europe joins the race for solid oxide fuel cells

Two German companies have signed a co-operation agreement that will see the development of solid oxide fuel cell stacks (SOFC) that could blunt the drive towards 42-volt auto electrical systems.This is a short news story only. Visit www.metal-powder.net for the latest powder metallurgy industry news.     

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...     

固体氧化物燃料电池阴极材料La1-xSrxMnO3的制备方法

固体氧化物燃料电池是目前最成熟、最有发展潜力的燃料电池,具有广泛的应用前景。文章综述了该电池阴极材料La1-xSrxMnO3的制备方法,比较了各种制备方法的优缺点,介绍了一种新型的制备方法—自蔓延高温合成法的研究进展。指出:自蔓延高温合成法能显著缩短阴极材料的制备周期和减少能耗,从而能降低其制造成本、促进其实用化和产业化。     

欧洲固体氧化物燃料电池（SOFC）产业化现状

固体氧化物燃料电池（SOFC）具有燃料适用范围广、能量转换效率高（发电效率40%～60%,综合能效≥80%）、全固态结构、模块化组装、零污染等优点,作为固定式或分布式发电可增强电网清洁供电的能力、安全性、可靠性和稳定性。SOFC具有多种不同的结构,其发电规模覆盖几十瓦至百兆瓦,可根据不同的应用场景选择不同的结构,应用场景主要包括固定式发电、分布式供电、热（冷）电联供、交通车辆辅助动力电源等领域。国内的SOFC技术发展较晚,目前已取得一定的研究进展,并且能够自主研发出十几千瓦的SOFC发电系统,但与国际领先水平还有很大的差距,主要体现在输出功率、生产成本及使用寿命等方面。欧洲的SOFC技术处于国际领先水平,具有一批成功实现产品化的公司,通过对其技术和产品的调研,可深入的了解欧洲SOFC技术现状和发展趋势,为国内SOFC技术的发展提供借鉴作用。      

Oxidation resistance,thermal expansion and area specific resistance of Fe-Cr alloy interconnector for solid oxide fuel cell

It is promising for metal especially ferritic stainless steel(FSS)to be used as interconnector when the solid oxide fuel cell(SOFC)is operated at temperature lower than 800°C.However,there are many challenges for FSS such as anti-oxidant,poisoning to cathode and high area specific resistance(ASR)when using as SOFC interconnector.The effect of Cr content(12-30 mass%)in Fe-Cr alloys on thermal expansion coefficient(TEC),oxidation resistance,microstructure of oxidation scale and ASR was investigated by thermo-gravimetry,scanning electron microscopy,energy dispersive spectroscopy and four-probe DC technique.The TEC of Fe-Cr alloys is(11-13)×10~(-6) K~(-1),which excellently matches with other SOFC components.Alloys have excellent oxidation resistance when Cr content exceeds 22mass% because of the formation of chromium on the surface of alloy.The oxidation rate constants kdand ksdecrease rapidly with increasing the Cr content and then increase slowly when the Cr content is higher than 22mass%.The kinetic results indicate that Cr evaporation must be considered at high temperature for Fe-Cr alloys.After the alloys were oxidized in air at 800°C for500 h,log(ASR/T)(Tis the absolute temperature)presents linear relationship with 1/T and the conduct activation energy is 0.6-0.8eV(Cr16-30).Optimal Cr content is 22-26mass%considering the oxidation resistance and ASR.     

以粉末冶金制备固态氧化物燃料电池之连接板

在能源短缺的压力之下,新能源的开发已成为各工业化先进国家的开发主题。燃料电池开发可说是一项很有潜力的新能源供应机制,它可解决过去能源利用效率低及环境污染的问题。该文作者主要针对以金属铬粉为原料、采用粉术冶金工艺制备固态氧化物燃料电池连接板的需要,对粉末润滑剂的成形特性、烧结致密性与高温氧化等进行试验研究,以达到连接板高致密度的要求;以及找出适当的工艺参数,作为开发固态氧化物燃料电池连接板之基础。     

微波合成固体氧化物燃料电池阴极材料La1-xSrxMnO3的研究

采用微波技术合成了固体氧化物燃料电池阴极材料La1-xSrxMnO3样品，分别选择x=0.1,0.2,0.3,0.4和0.5合成了La0.9Sr0.1MnO3,La0.8Sr0.2Mn3,La0.7Sr0.3MnO3,La0.6Sr0.4MnO3和La0.5Sr0.5MnO3，用X射线衍射分析检测了样品的结构与组成，用电子扫描电镜考查了样品的形貌和粒度，电导率测量结果表明，样品的组成和烧结温度影响电导率。在系列样品中，组成为La0.7Sr0.3MnO3电导率最高；烧结温度1200℃和1300℃相比较，1300℃烧结后样品的电导率大幅度提高。     

CeO_2基固体氧化物燃料电池电解质研究

固体氧化物燃料电池(SOFCs)被誉为21世纪最具有发展潜力的能源技术之一.由于用稀土或碱土金属氧化物掺杂的CeO2在较低的温度下具有较高的氧离子电导率,是用作中低温固体氧化物燃料电池较理想的电解质材料.本文综述了近年来以掺杂的CeO2作电解质的SOFCs性能的研究情况,总结了提高、改善CeO2基固体电解质电性能的几种方法,并对今后的研究提出了自己的看法.     

Applications and recent advances of rare earth in solid oxide fuel cells

Solid oxide fuel cells (SOFCs) are an all-solid energy conversion device from the chemical energy of fuels to electric energy at intermediate and high temperatures. Up to now, massive efforts have been made in developing different components of solid oxide fuel cells, including electrolyte, anode, cathode and interconnect materials. Rare earth elements play an indispensable role in different components of SOFCs which have been extensively studied in the recent decades. In this review, we concentrate upon the rare earth application and recent advances in SOFCs and related materials. Materials structure involves perovskites, Ruddlesden-Popper, fluorite, spinel, pyrochlore, apatite and so on. Moreover, the effects of rare earth based oxides as matrix or dopants in different components are also discussed. Structures and properties of the materials are related to the element type, valence, coordination and ion radius. This article will provide a comprehensive research direction towards SOFCs components for their composition, structural design and mechanisms research.     

中温直接碳氢化合物固体氧化物燃料电池Cu—CeO2-ScSZ阳极的研究

采用共沉淀法合成了氧化钪稳定氧化锆（9mol％Sc2O3,ScSZ）末。应用热膨胀分析仪研究了ScSZ粉末的烧结特性,采用扫描电镜观察了烧结试样的微观组织,利用交流阻抗法测定了ScSZ电解质在500-900℃的电导率。制备了以ScSZ为电解质、Cu—CeO2-ScSZ为阳极、ScSZ—LSM为阴极的阳极支撑燃料电池。在700℃时,直接以氢气、丁烷和甲烷为燃料,测得的电池最大输出功率密度分别为280mW/cm^2、142mW／cm^2和120mW/cm^2。     

中温直接碳氢化合物固体氧化物燃料电池Cu-CeO2-ScSZ阳极的研究

采用共沉淀法合成了氧化钪稳定氧化锆(9 mol%Sc2O3,ScSZ)粉末.应用热膨胀分析仪研究了ScSZ粉末的烧结特性,采用扫描电镜观察了烧结试样的微观组织,利用交流阻抗法测定了ScSZ电解质在500～900℃的电导率.制备了以ScSZ为电解质、Cu-CeO2一ScSZ为阳极、ScSZ-LSM为阴极的阳极支撑燃料电池.在700℃时,直接以氢气、丁烷和甲烷为燃料,测得的电池最大输出功率密度分别为280 mW/cm2、142 mW/cm2和120 mW/cm2.     

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.     

Thermomechanical stresses in the ceramic and cerametallic layers of tube solid oxide fuel elements

A model is proposed to calculate the residual thermomechanical stresses in the layers of a tube solid oxide fuel cell (SOFC) that are caused by the difference between the linear thermal expansion coefficients of these layers. The distributions of the residual stresses in the cell layers that appear during the production of SOFC and under operating conditions are determined, and the regions of probable failure in the cell are revealed.     

镁铝复合氧化物的固相反应热力学计算及固相合成研究

采用固相法合成镁铝氧化物,通过固相反应的热力学计算得到临界温度值,并通过热重曲线分析反应的中间过程。加入AlF3参与到矿石固相合成反应中,通过XRD观察发现,AlF3能有效降低矿石固相合成温度近200℃,还起到助熔剂的作用。     

固体氧化物燃料电池阴极材料La1-xSrxMnO3的制备方法

固体氧化物燃料电池是目前最成熟、最有发展潜力的燃料电池,具有广泛的应用前景.文章综述了该电池阴极材料La1-xSrxMnO3的制备方法,比较了各种制备方法的优缺点,介绍了一种新型的制备方法-自蔓延高温合成法的研究进展.指出自蔓延高温合成法能显著缩短阴极材料的制备周期和减少能耗,从而能降低其制造成本、促进其实用化和产业化.     

用SHS法合成SOFC阴极材料La1-xSrxMnO3

采用自蔓延高温合成技术（SHS）制备固体氧化物燃料电池（SOFC）阴极材料La1-xSrxMnO3（LSM）; 研究成形压力、稀释剂添加量等参数对反应过程及合成产物性能的影响; 采用XRD、ICP研究SHS法合成LSM的物相和晶型结构. 结果表明： 自蔓延高温合成产物为钙钛矿结构菱方晶系La1-xSrxMnO3, Sr含量的变化引起合成产物特征峰的位置和半峰宽变化; 随着Sr含量的增加, 合成的LSM粉末粒度变细, 晶格常数a和c减小.     

Activities of phosphorus in liquid copper by solid oxide galvanic cell

The oxygen partial pressures of the equilibrium among solid magnesia, phosphorus-containing liquid copper and trimagnesium phosphate were measured by means of solid-oxide galvanic cells. These cells incorporated magnesia-stabilized zirconia as solid electrolyte and Mo + MoO₂ as reference electrode at 1 473, 1 523 and 1 573 K. Then the activities of phosphorus in liquid copper, and the free energy of dissolution of diatomic phosphorus gas into liquid copper at infinite dilution refered to 1 wt.pct. were determined.     

Green mediated synthesis of lanthanum doped zinc oxide: Study of its structural,optical and latent fingerprint application

The present paper summarises the synthesis of La³⁺ doped zinc oxide nanoparticles using Aloe vera gel by solution combustion method and the characterization using a powder X-ray diffractometer (PXRD), a transmission electron microscope (TEM), an X-ray photometric spectrometer (XPS), a Raman spectrometer and their applications in optical devices and latent fingerprinting. PXRD pattern confirms the crystallite size of La³⁺ doped ZnO varies from 13 to 20 nm. Crystallite size varies inversely with doping concentration. Photoluminescence properties are found to be the maximum for 2 mol% doping concentration. PL spectra extends the use of ZnO:La³⁺ nanoparticles in blue green LED. These nanoparticles also have superior property as a fluorescent labels in fingerprints.