(2012) Electrochemical performance of spin coated dense BaZr0.80Y0.16Zn0.04O3-d membranes

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ZnO对8YSZ电解质材料的烧结性与电化学性能的影响

ZnO对8YSZ电解质材料的烧结性与电化学性能的影响江虹1,2戴郭瑞松1戴任戴勋1(1. 天津大学，先进陶瓷与加工技术教育部重点实验室，天津 300072；2. 贵州广播电视大学理工处，贵阳 550004)摘要：用机械混合方法，在8%(摩尔分数，下同)Y2O3稳定的ZrO2 (8% in mole yttria stabilized zirconia，8YSZ)中添加ZnO量分别为0，1%，2%，3%，4%，在不同温度下常压烧结制备了ZnO:8YSZ电解质。

研究了烧结温度和ZnO含量对ZnO:8YSZ样品的烧结性、致密度、弯曲强度和电导率的影响。

由ZnO:8YSZ电解质作为支撑组装了单电池，对电池的性能进行测试和评价。

结果表明：在8YSZ中添加ZnO能改善8YSZ材料的烧结性，1400℃烧结2h的4%ZnO:8YSZ样品的致密度达99.9%，3%ZnO:8YSZ样品的弯曲强度超过200MPa，获得明显提高。

4%ZnO:8YSZ样品在800℃下的电导率达1.68×10–2 S/cm。

在相同工作条件下，ZnO:8YSZ单电池比8YSZ单电池具有更好的工作性能和更高的效率，以3%ZnO:8YSZ单电池性能最好。

关键词：烧结性；电导率；氧化钇稳定氧化锆；氧化锌中图分类号：TM242 文献标志码：A 文章编号：0454–5648(2010)08–1434–06EFFECTS OF ZnO ADDITIVE ON SINTERABILITY AND ELECTROCHEMICALPERFORMANCES OF 8YSZ ELECTROLYTEJIANG Hong1,2，GUO Ruisong1，REN Jianxun1(1. Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin University,Tianjin 300072; 2. Guizhou Broadcasting and Television College, Guiyang 550004, China)Abstract: ZnO:8YSZ (8% in mole yttria stabilized zirconia) electrolyte samples with different amounts of ZnO at 0, 1% (in mole, the same below), 2%, 3% and 4% were sintered at different temperatures in air. The effects of sintering temperature and ZnO content on the sinterability, relative density, bending strength and conductivity of the ZnO:8YSZ sample were investigated. The cell perform-ances were measured and evaluated using ZnO:8YSZ electrolyte supported configuration. The results show that the addition of ZnO can improve the sinterability of 8YSZ electrolyte. The relative density of 4% ZnO:8YSZ sample sintered at 1400 for 2℃h reaches 99.9%. The bending strength of 3%ZnO:8YSZ sample increases obviously compared with traditional YSZ, reaching over 200MPa. Total conductivity of 4% ZnO:8YSZ sample is 1.68×10–2 S/cm at 800. The cell of ZnO℃:8YSZ as electrolyte has better perform-ance and higher efficiency than that of 8YSZ as electrolyte in equal working condition, and the cell performance of 3%ZnO:8YSZ as electrolyte is better.Key words: sinterability; conductivity; yttria stabilized zirconia; zinc oxide摩尔分数为8%～10%氧化钇(Y2O3)稳定的ZrO2材料(yttria stabilized zirconia，YSZ)，具有优良的氧离子传导特性，在氧化、还原气氛中稳定性好，是固体氧化物燃料电池(solid oxide fuel cell，SOFC)中应用最普遍的固体电解质材料。

nature

本科生科研训练题目高能量密度柔性赝电容器中的二维磷酸氧钒超薄结构（翻译）院系物理科学与技术学院专业物理学基地班年级2012级学生姓名李赫学号**********二0一三年十二月二十日natureCOMMUNICATIONS2013年2月5号收到稿件2013年8月12日接受稿件2013年9月12日发表稿件DOI: 10.1038/ncomms3431高能量密度柔性赝电容器中的二维磷酸氧钒超薄结构二维材料一直以来在柔性薄膜型超级电容器，以及表现有关灵活性，超薄度甚至透明度的强劲优势上都是一个理想的构建平台。

要探索新的具有高电化学活性的二维赝电容材料，我们需要获得具有高能量密度的柔性薄膜超级电容器。

这里我们介绍一个无机石墨烯类似物，a1钒，一种少于6个电子层的磷酸盐超薄纳米片来作为一个有发展前景的材料去构建柔性全固态超薄赝电容器。

这种材料展示了一个在水溶液中氧化还原电位(~1.0V)接近纯水电化学窗口电压（1.23V）的赝电容柔性平面超级电容器。

通过层层组装构建出的柔性薄膜型超级电容器的氧化还原电位高达1.0V，比容量高达8360.5 μF∙cm-2，能量密度达1.7 mWh ∙cm-2，功率密度达5.2 mW∙cm-2。

现在，便携式消费电子产品的需求在快速增长，如柔性显示器，手机和笔记本电脑，极大推动了在全固态下的柔性能源设备的开发。

作为未来一代的储能装置，柔性薄膜型超级电容器在全固态下提供柔韧性，超薄型和透明度的协同效益。

在不同的类型的超级电容器中，与电双层电容器相比，赝电容器因为自身的高活性表面的电极材料可以快速发生的氧化还原反应而具有明显优势。

与锂离子电池相比，它表现出更高的能量密度，以及更高的功率密度。

因此，承载着为实现高性能的柔性薄膜型超级电容器的全固态伟大的承诺（FUSA）与电容行为。

具有赝电容特性的二维（2D）类石墨烯材料代表着一个有前途的方向可以去实现全固态下的高能量密度柔性超级电容器，和潜在的优良的机械柔性。

气相辅助刮刀涂布法制备钙钛矿薄膜

３．Ｎｏ．１８ｔｈＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅｏｆＣｈｉｎａＥｌｅｃｔｒｏｎｉｃｓＴｅｃｈｎｏｌｏｇｙＧｒｏｕｐＣｏｒｐｏｒａｔｉｏｎ，Ｔｉａｎｊｉｎ３００３８４，Ｃｈｉｎａ）Ｃｏｒｒｅｓｐｏｎｄｉｎｇａｕｔｈｏｒ，Ｅｍａｉｌ：ｃａｏｈ＠ｔｊｕｔ．ｅｄｕ．ｃｎ
Ａｂｓｔｒａｃｔ：Ｐｅｒｏｖｓｋｉｔｅｓｏｌａｒｃｅｌｌｓ（ＰＳＣｓ）ｈａｖｅａｔｔｒａｃｔｅｄｗｉｄｅｓｐｒｅａｄａｔｔｅｎｔｉｏｎｄｕｅｔｏｔｈｅｉｒｈｉｇｈｅｆｆｉｃｉｅｎｃｙａｎｄ
依赖溶液旋涂工艺或ＰＶＤ，使其难以实现大面积
连续制备。为克服这一问题，喷涂法已经被用在
ＣＶＤ工艺中制备前驱膜，单块大面积电池（２ｃｍ２）光电转化效率可达１６２％。［３３］
刮刀涂布法（ＤｏｃｔｏｒＢｌａｄｅｃｏａｔｉｎｇ，ＤＢ），是一
种利用刮板将溶液刮涂到基底上的方法。其制备
矿薄膜。但是，ＰＶＤ需要使用高真空装置以及长
时间抽真空来制备器件，因此时间和能量成本高，
限制了其在廉价钙钛矿光伏器件制造中的应用［３０３１］。
气相辅助溶液法（ＶＡＳＰ）是一种将前驱卤化
铅薄膜在有机胺卤化物蒸汽中转化为钙钛矿的化学气相沉积（ＣＶＤ）工艺［３２］。它结合了溶液法和
收稿日期：２０１９０１０７；修订日期：２０１９０２２８基金项目：国家自然科学基金项目（Ｎｏ．６１５０４０９７）；天津市自然科学基金（Ｎｏ．１７ＪＣＹＢＪＣ２１０００，Ｎｏ．１８ＪＣＺＤＪＣ９６９００）；
天津市优秀企业科技特派员项目（Ｎｏ．１８ＪＣＴＰＪＣ４９９００）；天津市教委基金（Ｎｏ．２０１７ＺＤ１４，Ｎｏ．２０１８ＺＤ０９）ＳｕｐｐｏｒｔｅｄｂｙＮａｔｉｏｎａｌＮａｔｕｒａｌＳｃｉｅｎｃｅＦｏｕｎｄａｔｉｏｎｏｆＣｈｉｎａ（Ｎｏ．６１５０４０９７）；ＮａｔｕｒａｌＳｃｉｅｎｃｅＦｏｕｎｄａｔｉｏｎｏｆＴｉａｎｊｉｎ（Ｎｏ．１７ＪＣＹＢＪＣ２１０００，Ｎｏ．１８ＪＣＺＤＪＣ９６９００）；ＴｅｃｈｎｉｃａｌＥｘｐｅｒｔ（Ｎｏ．１８ＪＣＴＰＪＣ４９９００）；ｔｈｅＳｃｉｅｎｔｉｆｉｃＤｅｖｅｌｏｐｉｎｇＦｏｕｎｄａｔｉｏｎｏｆｔｈｅＴｉａｎｊｉｎＥｄｕｃａｔｉｏｎＣｏｍｍｉｓｓｉｏｎ（Ｎｏ．２０１７ＺＤ１４，Ｎｏ．２０１８ＺＤ０９）

纳米锂镧锆钽氧粉体复合聚氧化乙烯制备的固态电解质电化学性能的研究

纳米锂镧锆钽氧粉体复合聚氧化乙烯制备的固态电解质电化学性能的研究赵宁;李忆秋;张静娴;狄增峰;郭向欣【摘要】与采用液体电解液的传统二次锂离子电池相比,固态二次锂电池在高能量密度和安全性方面具有显著的潜在优势,近年来成为国内外的研究热点.作为固态二次锂电池的核心组成,固态电解质需要具备高离子电导率、宽电化学窗口、对锂稳定、力学性能优以及可抑制锂枝晶等特性.为达到以上要求,本工作探索制备了由纳米钽掺杂锂镧锆氧(LLZTO)粉体与聚氧化乙烯(PEO)复合的有机-无机复合固态电解质膜材料,对比研究了在有机物PEO中添加锂盐和不添加锂盐对固态电解质膜电导率及电化学特性的影响.发现在PEO-LLZTO复合电解质膜中,虽然PEO不导电,但界面处存在的渗流效应可极大提高膜的总电导率,室温离子电导率可达到2×10-4 S/cm.这一数值虽然略低于PEO-LiTFSI-LLZTO复合电解质膜(室温条件下电导率为6×10-4 S/cm),但无锂盐添加的PEO-LLZTO复合电解质膜表现出较好的电化学稳定性和较强的抑制锂枝晶的能力.将PEO-LLZTO复合电解质膜与Li/LiFePO4和Li/LiFe0.15Mn0.85PO4组装成软包电池,在0.1C、60℃的测试条件下可充分发挥正极材料的容量,并可稳定循环200次以上.【期刊名称】《储能科学与技术》【年(卷),期】2016(005)005【总页数】8页(P754-761)【关键词】固态电解质;聚氧化乙烯;LLZTO纳米粉;渗流效应【作者】赵宁;李忆秋;张静娴;狄增峰;郭向欣【作者单位】中国科学院上海硅酸盐研究所,上海200050;中国科学院上海硅酸盐研究所,上海200050;中国科学院上海微系统与信息技术研究所,上海200050;中国科学院上海微系统与信息技术研究所,上海200050;中国科学院上海硅酸盐研究所,上海200050【正文语种】中文【中图分类】TM911固态二次锂电池是采用固态电解质、复合负极或金属锂负极、复合正极的一种可充电电池，它的基本构型如图1所示。

电导池

Effects of sulfonated polyether-etherketone (SPEEK)and composite membranes on the proton exchange membrane fuel cell (PEMFC)performanceErce S x engu ¨l a ,Hu ¨lya Erdener a ,R.Gu ¨ltekin Akay a ,Hayrettin Yu ¨cel a ,Nurcan Bac¸b ,_Inc _I Erog ˘lu a ,*a Chemical Engineering Department,Middle East Technical University,06531Ankara,TurkeybChemical Engineering Department,Yeditepe University,34755Istanbul,Turkeya r t i c l e i n f oArticle history:Received 8March 2008Received in revised form 20August 2008Accepted 22August 2008Available online 5November 2008Keywords:PEM fuel cells SPEEKComposite membrane Zeolite betaMembrane electrode assembly (MEA)a b s t r a c tSulfonated polyether-etherketone (SPEEK)has a potential for proton exchange fuel cell applications.However,its conductivity and thermohydrolytic stability should be improved.In this study the proton conductivity was improved by addition of an aluminosilicate,zeolite beta.Moreover,thermohydrolytic stability was improved by blending poly-ether-sulfone (PES).Sulfonated polymers were characterized by posite membranes prepared were characterized by Electrochemical Impedance Spectroscopy (EIS)for their proton conductivity.Degree of sulfonation (DS)values calculated from H-NMR results,and both proton conductivity and thermohydrolytic stability was found to strongly depend on DS.Therefore,DS values were controlled time in the range of 55–75%by controlling the reaction time.Zeolite beta ﬁllers at different SiO 2/Al 2O 3ratios (20,30,40,50)were synthesized and characterized by XRD,EDX,TGA,and SEM.The proton conductivity of plain SPEEK membrane (DS ¼68%)was 0.06S/cm at 60 C and the conductivity of the composite membrane containing of zeolite beta ﬁlled SPEEK was found to increase to 0.13S/cm.Among the zeolite Beta/SPEEK composite membranes the best conductivity results were achieved with zeolite beta having a SiO 2/Al 2O 3ratio of 50at 10wt%loading.Single fuel cell tests performed at different operating temperatures indicated that SPES/SPEEK membrane is more stable hydrodynamically and also performed better than pristine SPEEK membranes which swell excessively.Membrane electrode assemblies (MEAs)were prepared by gas diffusion layer (GDL)spraying method.The highest performance of 400mA/cm 2was obtained for SPEEK membrane (DS 56%)at 0.6V for a H 2–O 2/PEMFC working at 1atm and 70 C.At the same conditions Naﬁon Ò112gave 660mA/cm 2.It was observed that the operating temperature can be increased up to 90 C with polymer blends containing poly-ether-sulfone (PES).ª2008International Association for Hydrogen Energy.Published by Elsevier Ltd.All rightsreserved.1.IntroductionThe increased interest in the potential use of proton exchange membrane fuel cells (PEMFCs)is due to the factthat they can offer high efﬁciencies with almost zero emis-sion of pollutant gases.Moreover,the quick start-up times and high ﬂexibility to load changes are other advantages.The PEMFC,which uses hydrogen and oxygen (or air)as reactant*Corresponding author .Tel.:þ903122102609;fax:þ903122102600.E-mail address:ieroglu@.tr (_Inc _I Erog˘lu).A v a i l a b l e a t w w w.s c i e n c e d i r e c t.c o mj o u r n a l h o m e p a g e :w w w.e l s e v i e r.c o m /l o c a t e /h e0360-3199/$–see front matter ª2008International Association for Hydrogen Energy.Published by Elsevier Ltd.All rights reserved.doi:10.1016/j.ijhydene.2008.08.066i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n e n e r g y 34(2009)4645–4652gases,is particularly attractive due to high power outputs delivered at low operating temperatures(50–80 C)and pres-sures(1–3atm).The electrochemical reaction occurs in the membrane electrode assembly(MEA),which is considered to be the heart of PEMFC[1].When hydrogen gas is fed to the anode side of the cell,it separates into its protons and elec-trons.The protons are conducted through the membrane electrolyte whereas the free electrons produced at the anode move through an external circuit to the cathode.At the cathode side,oxygen gas combines with the electrons and protons.Theﬁnal products of such a cell are electric power, water,and heat.They are ideally suited for transportation and other appli-cations.PEM fuel cell stacks operating on hydrogen can be 40–50%electrically efﬁcient and80%system efﬁcient if the heat recovery is included.The research and development of PEM fuel cell stacks based on different materials,structures and fabricating methods are going on[2–4].05pThe key component of PEMFC is the membrane which enables proton transfer between anode and cathode.Current applications prefer NaﬁonÒ(DuPont)which belongs to the perﬂourosulfonic acid(PFSA)family[5].However,there are two signiﬁcant drawbacks associated with the use of Naﬁon membrane.First,the cost of NaﬁonÒmembrane is still too high for commercial applications.Second,it is not possible to operate at high temperatures with NaﬁonÒ.High temperature operation is useful for enhanced reaction kinetics and reduced catalyst poisoning by fuel impurities.Therefore,efforts are concentrated on developing alternate membranes that are capable of operating at higher temperatures.Phosphoric acid doped polybenzimidazole is one of the most successful elec-trolyte membranes[6].Other,the most popular candidates are polyaromatic hydrocarbon polymers,especially PEEK,due to its high thermal and mechanical stability,low price and improvable proton conductivity via post-sulfonation. Although,it is improvable,the conductivity of SPEEK membrane is still lower than that of NaﬁonÒ.Its proton conductivity depends on the degree of sulfonation(DS). However,the mechanical properties tend to deteriorate as the DS increases.Highly sulfonated polymers will swell signiﬁ-cantly at high temperature and humidity[7].2.Experimental2.1.Zeolite synthesis and characterizationZeolite beta crystals were synthesized hydrothermally according to the batch composition2.2Na2O:1.0Al2O3:x SiO2: 4.6(TEA)2O:440H2O at various SiO2/Al2O3ratios[8].In hydrothermal synthesis,an alkaline precursor solution was prepared by dissolving sodium aluminate(52.9wt%Al2O3, 45.3wt%Na2O,Riedel de Hae¨n)in deionized water prior to addition of the structure directing agent,tetraethyl ammo-nium hydroxide(TEAOH)solution(20or35wt%in water, Aldrich).The silica precursor solution,mainly composed of colloidal silica(SiO2),(Ludox40wt%suspension in water, Sigma–Aldrich),was added to the alumina precursor solution and gelation was observed.This gel was poured into Teﬂon-lined steel autoclaves were kept at constant temperature (150 C)under autogenously pressure for a reaction period of 5–15days.The autoclaves were then taken out of the oven, cooled,ﬁltered,and the zeolite product was dried at80 C. Zeolite beta was calcined at550 C,and then converted into more proton conductive Hþform after acid treatment with 95–98wt%H2SO4(Merck).Synthesized zeolite beta samples were characterized by X-Ray Diffraction(XRD)to conﬁrm beta structure,Thermogravimetric Analysis(TGA)for its thermal stability,Energy Dispersive X-Ray Analysis(EDX)to compare theoretical Si/Al ratio with that in synthesized form,and Scanning Electron Microscopy(SEM)for crystal morphology and average particle size.2.2.Polymer sulfonation2.2.1.Sulfonation of PEEK polymerPEEK polymer was obtained as pellets(Polyoxy-1,4-pheney-leneoxy-1,4-pheneyelene carbonyl-1,4-phenylene,Aldrich, Mw¼20,800).PEEK pellets were ground to reduce the disso-lution time of the polymer and dried at100 C in vacuum oven prior to post-sulfonation.In the post-sulfonation reaction,the polymer was dissolved in H2SO4to give a dark,viscous solu-tion then the degree of sulfonation(DS)was controlled by changing the reaction times at a constant temperature(50 C) [9].Reaction was stopped by pouring the polymer solution in icy-water and white polymer strings were obtained.The decanted polymer strings were washed with deionized water and dried in vacuum oven.2.2.2.Sulfonation of PES polymerPES polymer cannot be easily sulfonated as PEEK in H2SO4. Therefore chlorosulfonic acid(CSA)was used in the sulfona-tion reaction.The polymer wasﬁrst dissolved in H2SO4 (usually1/10w/v)then a predetermined amount of CSA was added drop wise into the solution.Reactions were carried out at around5 C by using ice-cold water around reaction vessel to prevent cross linking and decomposition of the polymer chains which may occur above20 C.At the end of the pre-determined reaction time solution was poured into cold ice-water and the precipitate wasﬁltered and washed until excess acid is removed and dried at90 C.2.2.3.Determination of DS by H-NMRThe H-NMR spectra were obtained by using Bruker Biospin NMR spectrometer with a resonance frequency of300MHz. Samples were prepared by dissolving10–20mg polymer in DMSO-d6.The degree of sulfonation,DS,was determined by integration of distinct aromatic signals determined quantita-tively by using H-NMR spectroscopy.In H-NMR the presence of sulfonic acid group’s results in a0.25ppm down-ﬁeld shift of the hydrogen H E compared to H C,H D in the hydroquinone ring[10].The nomenclature of the aromatic protons for the SPEEK repeat unit is given in Scheme1below.The presence of sulfonic acid groups in the structure causes a distinct signal for protons at E position.Estimates for the H E content which is equal to the sulfonic acid group content can be done according to the intensity of this signal[10].The H-NMR signal for sulfonic acid group is difﬁcult since the proton is labile.The ratio of peak area of distinct H E signalsðA HEÞand integrated areas of the signalsi n t e r n a t i o n a l j o u r n a l o f h y d r o g e n e n e r g y34(2009)4645–4652 4646corresponding to all the other aromatic hydrogen’s ðA H AA 0BB 0CD Þare expressed as:n 12À2n¼A H EPA H AA 0BB 0CD ð0 n 1Þ(1)DS ¼n Â100%(2)2.3.Membrane castingThe SPEEK polymer was dissolved in n-n,dimethyl-acet-amide (DMAc,Merck)and stirred overnight with magneticstirrer.Then,zeolite H þ-beta was added to the solution at certain quantities.The solution was mixed under ultrasonic mixing overnight and then drop-casted onto petri dishes.The membranes were dried in vacuum oven at 60–120 C for 24h.For blend membranes,proportional amounts of sulfonated PEEK and PES polymers were dissolved in DMAc to give a 10wt%polymer solution.The solution was stirred by magnetic stirrer overnight prior to mixing in ultrasonic water bath to obtain a homogenous solution.After mixing,the homogenous solution was cast onto Petri dishes and dried from 60 C to 120 C in 24h.2.4.Proton conductivity analysisThe proton conductivity of the membranes was measured by AC Electrochemical Impedance (EIS)technique over a frequency range of 1–300kHz with an oscillating voltage using GAMRY PCL40Potentiostat system.All measurements were performed in longitudinal direction,under water vapor atmosphere at 100%relative humidity with a 4probe EIS as a function of temperature.The specimens were prepared as 1Â5cm membrane strips and sandwiched into a Teﬂon Òconductivity cell with Pt electrodes (Fig.1).The specimen and the electrodes were ﬁxed by nuts and bolts.The conductivity,s ,of samples in longitu-dinal direction was calculated in Siemens per cm from the impedance data by using Eq.(3);s ¼L RWd(3)where;L is the distance between the electrodes,W is the width of the membrane,d is the thickness of the membraneand R is the low intersect of the high-frequency semi-circle on a complex impedance plane with the Re(Z )axis.Proton conductivity measurements were performed in a closed jar with water at the bottom in a temperature controlled bath with mechanical stirrer.The temperature and relative humidity (RH)of the vapor inside the jar were measured with a thermocouple and RH meter.Conductivities were measured several times at each temperature until they were constant.2.5.MEA preparationMEAs were prepared from the membranes cast,which resul-ted in good proton conductivities during electrochemical impedance spectroscopy analyses.Gas diffusion layer (GDL)Spraying technique was applied for the preparation of MEAs [10].In the ﬁrst step,catalyst ink,which is comprised of 20wt%Pt on Vulcan XC-72catalyst (E-Tek),5wt%Naﬁon Òsolution (Ion Power Inc),distilled water,and 2-propanol,were prepared and mixed in ultrasonic bath for 2h.In order to clean and increase the proton conductivity of the membranes,they were conditioned by boiling in 0.5M H 2SO 4solution and distilled water at 80 C.In order to coat the GDLs with catalyst layer,the anode and cathode side GDLs were ﬁxed on a paper frame.The catalyst ink was sprayed until the desired catalyst loading (0.4mgPt/cm 2for both anode and cathode sides)was achieved.The catalyst loading was controlled by just weighing the GDLs at different times.After the GDLs were loaded with catalyst,they were kept in oven at 80 C for 1h in order to completely remove the liquid components of catalyst ink.Then,they were weighed again.To complete the MEA,the GDLs were hot pressed to the membrane at 130 C [11].2.6.Performance testsPerformances of fabricated MEAs were measured via the PEMFC test station built at METU Fuel CellTechnologyScheme 1–Aromatic protons of PEEK andSPEEK.Fig.1–Proton conductivity cell.i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n e n e r g y 34(2009)4645–46524647Laboratory.A single cell PEMFC (Electrochem FC05-01SP-REF)having 5cm 2active area was used in the experiments.The external load was applied by means of an electronic load (Dynaload ÒRBL488),which can be controlled either manually or by the computer.The current and voltage of the cell were monitored and logged throughout the operation of the cell by fuel cell testing software (FCPower Òv.2.1.102Fideris).The fabricated MEA was placed in the test cell and the bolts were tightened with a torque 1.7Nm on each bolt.The cell temper-ature was adjusted and the temperatures of the humidiﬁers and gas transfer lines were set 10 C above the cell tempera-ture.After the preset temperatures were achieved,hydrogen and oxygen are supplied to the cell at a rate of 0.1slpm.The cell was operated at 0.5V until it came to steady state.After steady state was achieved,starting from the OCV value,the current–voltage data was logged by changing the load.3.Results3.1.Zeolite beta characterizationThe XRD pattern of zeolite beta that was hydrothermally synthesized at SiO 2/Al 2O 3ratio of 20is given in Fig.2a.The characteristic peaks of zeolite beta were observed at 2q w 7.8 and 2q w 22.4 as stated in literature [12].The morphology of the zeolites was explored with SEM and the average particle size distribution was found to be around 1micron as shown in SEM Picture below (Fig.2b).Another important characteristicof zeolite beta is its high thermal stability.Thermogravimetric Analyses of zeolite beta crystals showed that the ﬁrst weight loss was around 465 C as given in Fig.2c and it demonstrates the removal of the structure directing agent (SDA)from the zeolite structure.Thus,zeolite crystals were calcined at higher temperatures to remove SDA completely.The thermal decomposition temperature of zeolite beta particles was around 850 C,this means that the zeolite beta particles are stable up to this temperature.Hence,they are suitable for fuel cell applications.As a result of the EDX analysis it was found that the Si/Al ratio in the structure of the as synthesized zeolite Na-Beta is close to the value of Si/Al ratio in the batch solution (theo-retical)(Table 1).3.2.Sulfonated polymer characterizationsDegree of sulfonation (DS)values of the sulfonated polymers was determined by using H-NMR data as described intheFig.2–(a)XRD pattern of as synthesized zeolite beta (SiO 2/Al 2O 3[20)(b)SEM micrograph of as synthesized zeolite beta (c)TGA of as synthesized zeolite beta.i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n e n e r g y 34(2009)4645–46524648experimental section.The signal around7.6ppm chemical shifts corresponds to the aromatic proton H E and its area relative to the other aromatic protons shows the extent of DS (data are not given).The degree of sulfonation is directly related to the reaction time,temperature and the amount of the sulfonation agent used.At higher temperatures the reaction kinetics is enhanced thus higher degrees of sulfonation are achieved. PEEK sulfonation proceeds very slow at room temperature and takes several days to reach a DS above50%.However at around50 C this time decreases to several hours as shown in Fig.3which is consistent with the literature[13].DS of PES was determined similarly as reported in the literature[14].Since sulfonation of PES is more difﬁcult than that of PEEK because of the electrophilic sulfone linkage,DS was around20%.Therefore,conductivity of SPES samples was lower than SPEEK.Since swelling and thermohydrolytic stability strongly depends on DS,SPES membranes showed better stability and low swelling.These properties can becombined by blending these compatible polymers.3.3.Proton conductivity of composite membranesThe objective of introducing zeolite particles into the polymer matrix was to enhance the proton transfer through the membrane by retaining water within the membrane and to create water mediated pathways while contributing their own proton conductivity.The hydrophilic zeolite particles improved the water retention property of the SPEEK membranes.Above60 C,the composite membranes absor-bed too much water and swelling problem was observed above this temperature(Fig.4).Thus,the proton conductivity analyses of composite membranes were limited up to this temperature.The proton conductivities of plain and composite membranes were measured at room temperature before and after treatment with1M HCl.Acid treatment was performed after the casting process,and all the membranes were kept in 1M HCl for2h for complete protonation.Acid treated membranes always result in higher conductivities naturally since all the available ion exchange sites are saturated with protons(–SO3H).All membranes were washed and hydrated with deionized water prior to measurement.As shown in Fig.5,the membranes with higher DS were resulted in better proton conductivities.Proton transfer enhances by increasing the number of acid sites enhances the proton transfer.Moreover,the effect of acid treatment on proton conductivity was explored in Fig.5and improved proton conductivities were observed after the acid treatment of the membranes.Thus,the membranes were treated with 1M HCl and washed with distilled water prior to proton conductivity measurements.Another important observation that could be made in Fig.5is the effect of zeolite particles. The composite membranes containing zeolite Beta have shown improved proton conductivities,for instance,0.11S/ cm was achieved for the composite membranes with74%DS after acid treatment.This is a promising result,since it is comparable with the conductivity of Naﬁon112membrane (0.1S/cm).Fig.3–Degree of sulfonation with respect to time ofsulfonationreaction.Fig.4–Water uptake capacities of plain and compositeSPEEKmembranes.Fig.5–Proton conductivity of plain and compositemembranes(with10wt%zeolite loading)at roomtemperature and fully hydrated state.i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n e n e r g y34(2009)4645–46524649In order to overcome the swelling problems observed in the pure and composite SPEEK membranes,SPEEK polymer was blended with a more hydrophobic polymer,namely sulfonated poly-ether-sulfone (SPES).The PES polymer was post-sulfonated and blended with SPEEK polymer at pre-determined proportions before membrane casting.However,owing to the poor proton transfer mechanism of SPES poly-mer,lower conductivities were obtained for blend membranes compared to the pure and composite SPEEK membranes.The proton conductivity measurements of pure SPEEK,SPES and blend membranes are given in Fig.6.So a trade-off between mechanical strength and conductivity exists for these blends.3.4.Performance testsFirst of all,the effect of using different catalyst ink solutions on the membrane performance is explored.The MEAs could be either prepared by using Naﬁon Òsolution or the original SPEEK solution [15].The comparison of two MEAs prepared by both Naﬁon Òand SPEEK solutions are given in Fig.7.It is apparent that the utilization of Naﬁon Òsolution in the catalyst ink resulted inhigher performance.Thus,Naﬁon Òsolution is utilized in the preparation of all MEAs.Second,the effect of operating temperatures on the performances of MEAs prepared by using SPEEK membranes (DS 56%)was examined and the results are given in Fig.8.It was observed that SPEEK based MEAs were not stable at high temperatures and they have punctured above 90 C.The best operating temperature of SPEEK based MEAs was found to be 70 C as demonstrated in Fig.9.The thermal stability of the membranes could be improved by blending with SPES poly-mer.It was noticed that,after the incorporation of 10wt%SPES into SPEEK membrane,the cell operating temperature could be increased up to 90 C without any damage to the membrane.As shown in Fig.9,the highest power output could be obtained at 80 C for SPES–SPEEK blend membranes.In order to understand the effect of sulfonation level on membrane performance,MEAs were prepared by using two membranes with different DS and the test results are displayed in Fig.10.It was not surprising to observe higher performance results for the MEA prepared by using the membrane at higher DS,since the proton transfer facilitates more easily with increased sulfonic acid groupcontents.Fig.6–Proton conductivities of plain and blendmembranes.Fig.7–Comparison of Naﬁon Òsolution and SPEEK solution for SPEEK based MEAs (cell temperature 708C).Fig.8–Effect of operating temperature on the performance of SPEEK (DS 56%)basedMEAs.Fig.9–Effect of sulfonation level on the performance of SPEEK based MEAs (cell temperature 708C).i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n e n e r g y 34(2009)4645–46524650Another important parameter affecting the MEA’s perfor-mance is membrane treatment.Since the proton transfer mechanism of both SPEEK and SPES membranes depend on the acidic character of the membranes,the acid treatment inﬂuences the membrane performance.The performance curves of both untreated and acid treated SPEEK based MEAs are given in Fig.11.The acid treated membrane showed almost threefold higher power density compared to the untreated membrane.The fuel cell performance of SPEEK membrane was compared with the performance of Naﬁon Òmembrane as given in Fig.12.The current density of plain SPEEK membrane (DS 56%)was 400mA/cm 2at 0.6V,whereas that of Naﬁon Ò112membrane was 660mA/cm 2under the same conditions.Although SPEEK membrane possesses lower fuel cell perfor-mance in comparison to the Naﬁon membrane,the result is promising when the relatively low cost of SPEEK membrane is considered.Moreover,the composite membrane SPEEK-Laponite exhibited better performance than the pure SPEEK membrane [9].Composite membranes prepared with inor-ganic additives such as silica,zeolite 4A and zeolite beta increase the proton conductivity and fuel cell performances of both Naﬁon Òand SPES-40polymer membrane [16].It should be emphasized that the same technique of MEA fabrication,cell assembling and operating conditions were used in the present work.The signiﬁcant difference of the obtained performances can be caused by various factors.One of them is the difference in the thickness of the membranes [17].Proton transfer mechanisms are also quite different in Naﬁon Òand SPEEK membranes.Degree of hydration is the factor that inﬂuences the proton conductivity of a membrane.The hydration is dependent on the phase separation between the hydrophobic polymer backbone and hydrophilic side chains [18].Naﬁon Òand SPEEK polymers both exhibit phase separated domains consisting of an extremely hydrophobic backbone which gives morphological stability and extremely hydrophilic side chains [18].Higher performances could be obtained for the membranes with higher DS values and for composite membranes.4.ConclusionThe development of alternative membranes at relatively low cost for fuel cell applications requires target properties such as suitable thermal and chemical stability,mechanical strength,comparable proton conductivity and fuel cell performance with the commercial PEM fuel cell membranes.In this study,zeolite beta composite membranes and blend membranes were developed.The proton conductivity of SPEEK was improved by addition of an aluminosilicate,zeolite beta.Also thermohydrolytic stability was improved by blending poly-ether-sulfone (PES).The proton conductivity of plain SPEEK membrane (DS ¼68%)was 0.06S/cm at 60 C and the conductivity of the composite membrane consisting of zeolite beta ﬁllers into SPEEK was further increased to 0.13S/cm.Among the zeolite beta/SPEEK composite membranes the best conductivity results were achieved with zeolite beta having a SiO 2/Al 2O 3ratio of 50at 10wt%loading.Single fuel cell tests performed at different operating temperatures indicated that SPES/SPEEK membrane ismoreFig.11–Effect of acid treatment on the performance of SPEEK (DS 56%)based MEAs (cell temperature 708C).Fig.12–The comparison of performances of Naﬁon Òand SPEEKmembranes.Fig.10–Effect of operating temperature on the performance of blend membranes.i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n e n e r g y 34(2009)4645–46524651stable hydrodynamically and also performed better than pristine SPEEK membranes which swell excessively. Membrane electrode assemblies(MEAs)were prepared by gas diffusion layer(GDL)spraying method.The highest perfor-mance,which is400mA/cm2,was obtained for SPEEK membrane(DS56%)at0.6V for a H2–O2/PEMFC working at 1atm and70 C.At the same conditions NaﬁonÒ112gave 660mA/cm2.It was observed that the operating temperature can be increased up to90 C with polymer blends containing poly-ether-sulfone(PES).AcknowledgementsThis study was supported by Turkish Scientiﬁc and Research Counsel with Project104M364and Turkish State Planning Organization Grant BAP-08-11-DPT2005K120600.r e f e r e n c e s[1]Barbir F.PEM fuel cells theory and practice.ElsevierAcademic Press;2005.[2]Corbo P,Migliardini F,Veneri O.Performance investigation of2.4kW PEM fuel cell stack in vehicles.International Journalof Hydrogen Energy2007;32:4340–9.[3]Hu M,Sui S,Zhu X,Yu Q,Cao G,Hong X,et al.A10kW classPEM fuel cell stack based on the catalyst-coated membrane (CCM)method.International Journal of Hydrogen Energy2006;31:1010–8.[4]Yan X,Hou M,Sun L,Liang D,Shen Q,Xu H,et al.ACimpedance characteristics of a2kW PEM fuel cell stackunder different operating conditions and load changes.International Journal of Hydrogen Energy2007;32:4358–64.[5]Bıyıkog˘lu A.Review of proton exchange membrane fuel cellmodels.International Journal of Hydrogen Energy2005;30: 1181–212.[6]Li Q,He R,Jensen JO,Bjerrum NJ.PBI-based polymermembranes for high temperature fuel cells–preparation,characterization and fuel cell demonstration.Fuel Cells2004;4(3):147–59.[7]Xing DM,Li BY,Liu FQ,Fu YZ,Zhang HM.Characterization ofsulfonated poly(ether ether ketone)/polytetraﬂuoroethylene composite membrane for fuel cell applications.Fuel Cells2005;5(3):406–11.[8]Akata B,Yilmaz B,Jirapnogphan SS,Warzywoda J,Sacco Jr A.Characterization of zeolite beta grown in microgravity.Microporous and Mezoporous Materials2004;71:1–9.[9]Chang JH,Park JH,Park G-G,Kim C-S,Park O-O.Proton-conducting composite membranes derived from sulfonated hydrocarbon and inorganic materials.Journal of PowerSources2003;124:18–25.[10]Zaidi SMJ,Michailenko SD,Robertson GP,Guiver MD,Kaliaguine S.Proton conducting composite membranes from polyether ether ketone and heteropolyacids for fuel cellapplications.Journal of Membrane Science2000;173:17–34.[11]Bayrakc¸eken A,Erkan S,Tu¨rker L,Erog˘lu_I.Effects ofmembrane electrode assembly components on protonexchange membrane fuel cell performance.InternationalJournal of Hydrogen Energy2008;33(1):165–70.[12]Holmberg BA,Hwang S-J,Davis ME,Yan Y.Synthesis andproton conductivity of sulfonic acid functionalized zeolitebeta nanocrystals.Microporous and Mesoporous Materials 2005;80:347–56.[13]Huang RYM,Shao P,Burns CM,Feng X.Sulfonation ofpolyetherether–ketone(PEEK):kinetic study andcharacterization.Journal of Applied Polymer Science2001;82: 2651–60.[14]Guan R,Zou H,Lu D,Gong C,Liu Y.Polyethersulfonesulfonated by chlorosulfonic acid and its membranecharacteristics.European Polymer Journal2005;41:1554–60.[15]S x engu¨l E,Erkan S,Erog˘lu_I,Bac¸N.Effect of gas diffusion layercharacteristics and addition of pore forming agents on theperformance of polymer electrolyte membrane fuel cells.Chemical Engineering Communications,2008;196(1–2):161–70.[16]Bac N,Nadirler S,Ma C,Mukerjee S.Inorganic–organiccomposite membranes for fuel cell applications.In:Proceedings international hydrogen energy congress andexhibition IHEC2005Istanbul,Turkey;2005.[17]Grigoriev SA,Lyutikova EK,Martemianov S,Fateev VN.Onthe possibility of replacement of Pt by Pd in a hydrogenelectrode of PEM fuel cells.International Journal of Hydrogen Energy2007;32:4438–42.[18]Hogarth M,Glipa X.High temperature membranes for solidpolymer fuel cells.Johnson Matthey Technology Center;2001 [Crown Copyright].i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n e n e r g y34(2009)4645–4652 4652。

氧化物热电材料研究进展

氧化物热电材料研究进展徐飞;李安敏;程晓鹏;孔德明【摘要】由于能源危机正在到来,废热回收已经成为解决能源短缺问题的有效途径之一,热电材料在废热收集环节中占有举足轻重的地位.其中,氧化物热电材料拥有抗氧化能力强、热稳定性好、原料相对低廉、制备工艺相对简单、无毒、无污染、使用寿命长等传统合金材料不具备的优点,但由于低的电导率因而限制了其在热电性能方面的表现.已经有大量研究发现,可以通过元素掺杂,改善氧化物热电材料的热电性能,氧化物热电材料再次受到广大研究者的关注.综述了氧化物热电材料的研究进展与今后的发展方向,着重阐述了以BiCuSeO为代表的氧化物热电材料的基本结构、性能特征与研究进展;评述了BiCuSeO材料Bi位、Cu位和O位掺杂研究以及BiCuSeO的结构优化;并简单介绍了NaCo2 O 4、Ca3 Co4 O 9、SrTiO 3、ZnO、In2 O 3热电材料的研究情况.【期刊名称】《功能材料》【年(卷),期】2019(050)004【总页数】11页(P4038-4048)【关键词】废热回收;热电材料;氧化物热电材料;BiCuSeO;元素掺杂【作者】徐飞;李安敏;程晓鹏;孔德明【作者单位】广西大学资源环境与材料学院,广西有色金属及特色材料加工重点实验室,南宁 530004;广西大学资源环境与材料学院,广西有色金属及特色材料加工重点实验室,南宁 530004;广西大学资源环境与材料学院,广西有色金属及特色材料加工重点实验室,南宁 530004;广西大学资源环境与材料学院,广西有色金属及特色材料加工重点实验室,南宁 530004【正文语种】中文【中图分类】TB340 引言对于热电材料研究，早在1822年,塞贝克(Seebeck)就在《普鲁士科学院报》中描述了一个这样的现象，在相互连接的不同导体中, 由于温度差就会出现自由磁子。

将两种不同金属材料连接，将连线一端处于较高温度下，温度为T1(热端)，而另一端处于开路且较低温度下，温度为T2(冷端)，这时冷端存在一个开路电压ΔV，这个现象被称为Seebeck效应，ΔV被称为Seebeck电压，ΔV与热冷两端的温差ΔT成正比，即ΔV=SΔT=S(T1-T2)(1)其中，S为Seebeck系数，只与材料自身的电子能带结构相关。

基于复合固体聚合物电解质的固态钠电池

第48卷第7期2020年7月硅酸盐学报Vol. 48，No. 7July，2020 JOURNAL OF THE CHINESE CERAMIC SOCIETY DOI：10.14062/j.issn.0454-5648.20200066 基于复合固体聚合物电解质的固态钠电池张强强1,2，苏醒1,2，陆雅翔1,2，胡勇胜1,2(1. 中国科学院物理研究所，北京 100190；2. 中国科学院大学，北京 100049)摘要：将钠离子导体Na-β’’-Al2O3作为活性填料引入聚氧化乙烯(PEO)/双(三氟甲基磺酰)亚胺钠(NaTFSI)固体聚合物电解质(SPE)中，得到有机–无机复合固体聚合物电解质(CPE)。

对SPE及CPE的相结构、相转变、离子电导率、离子迁移数及电化学稳定性等基础理化性质进行了表征分析，对两者在固态钠电池Na3V2(PO4)3@C||Na中的电化学性能进行了测试。

结果表明：Na-β’’-Al2O3的引入，有效提升了钠离子迁移数(SPE为0.19 ，CPE为0.71)和钠离子电导率(80℃时，SPE为1.65×10–4 S/cm，CPE为8.19×10–4 S/cm)。

基于CPE的固态钠电池表现出更加优异的循环稳定性，0.5C循环100周后容量保持率为93.9%，2.0C循环500周后容量保持率为74.0%。

关键词：聚氧化乙烯；双(三氟甲基磺酰)亚胺钠；固体聚合物电解质；复合固体聚合物电解质；钠电池中图分类号：TQ175 文献标志码：A 文章编号：0454–5648(2020)07–0939–08网络出版时间：2020–04–14A Composite Solid-state Polymer Electrolyte for Solid-state Sodium BatteriesZHANG Qiangqiang1,2, SU Xing1,2, LU Yaxiang1,2, HU Yongsheng1,2(1. Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;2. University of Chinese Academy of Sciences, Beijing 100049, China)Abstract: An organic-inorganic composite polymer electrolyte (CPE) was constructed via introducing an active filler of Na-β’’-Al2O3 into a solid-state polymer electrolyte (SPE) composed of poly(ethylene oxide) (PEO) and sodium bis(trifluoromethanesulfonyl)-imide (NaTFSI). The phase composition, ionic conductivity, Na+ transference number, and electrochemical stability were investigated. The electrochemical properties of SPE and CPE in Na||Na3V2(PO4)3@C solid-state sodium batteries were obtained. The results show that the CPE has a greater Na+ transference number of 0.71 than SPE (i.e., 0.19) and a higher Na+ conductivity of 8.19×10–4 S/cm than SPE (i.e., 1.65×10–4 S/cm) at 80℃. The CPE exhibits a superior cycling stability with capacity retentions of 93.9% after 100 cycles at 0.5C and 74.0% after 500 cycles at 2.0C in Na|CPE|Na3V2(PO4)3@C solid-state batteries.Keywords: poly(ethylene oxide); sodium bis(trifluoromethanesulfonyl)imide; solid-state polymer electrolyte; composite polymer electrolyte; sodium batteries随着社会的发展和对能源的巨大需求，人类对能源材料的开发不断增长。

非水基流延法制备Y3Fe485O12铁氧体基片

第41卷第3期人工晶体学报Vol．41No．32012年6月JOURNAL OF SYNTHETIC CRYSTALSJune ，2012非水基流延法制备Y 3Fe 4．85O 12铁氧体基片王科，杨建，丘泰，郭坚（南京工业大学材料科学与工程学院，南京210009）摘要：采用非水基流延成型工艺制备Y 3Fe 4．85O 12铁氧体基片，分析了分散剂种类及用量、固相含量等因素对浆料流变性能的影响，并研究制定流延膜片的排胶制度及烧结工艺。

研究结果表明：分散剂OP-85的分散效果明显优于磷酸三乙酯，其最佳的分散剂添加量为0．65wt%。

固相含量为25vol%和30vol%的浆料具有典型剪切变稀行为的Herschel /Bulkley 流体特征，适合于流延成型。

TG-DSC 数据分析说明：在温度为400ħ的条件下，流延膜片内的有机成分已经完全分解。

当烧结温度为1490ħ时，烧结膜片的体积密度达到5．09g /cm 3，接近于98%的理论密度。

X 射线衍射分析烧结膜片晶相纯正，扫描电镜照片显示烧结膜片的微观结构均匀。

关键词：流延成型；Y 3Fe 4．85O 12铁氧体基片；流变性能中图分类号：O469文献标识码：A文章编号：1000-985X （2012）03-0753-06Preparation of Y 3Fe 4．85O 12Ferrite Substrates by Non Aqueous Tape CastingWANG Ke ，YANG Jian ，QIU Tai ，GUO Jian（College of Materials Science and Engineering ，Nanjing University of Technology ，Nanjing 210009，China ）（Received 23December 2011，accepted 12March 2012）Abstract ：Y 3Fe 4．85O 12ferrite substrates were fabricated through non aqueous tape casting process．The effects of dispersant and solid loading on the rheological property of suspensions were characterized．The decomposition and sintering process for the tapes were discussed ，respectively．The test results showed that compared with Triethyl phosphate ，good dispersion for the dispersant OP-85was found in the slurry ，and the optimum addition reached to 0．65wt%．The suspensions including 25vol%and 30vol%solid loading belonged to the classical Herschel /Bulkley model ，namely exhibited obvious shear thinning behavior ，which was suitable for the tape casting．The DSC and TG analysis showed that the organic additives in the tapes decomposed completely at 400ħ．The bulk density of the tapes sintered at 1490ħreached 5．09g /cm 3，nearly up to about 98%of the theoretical density．In addition ，the second phase was not observed from the XRD patterns of Y 3Fe 4．85O 12sintered tapes and the SEM images showed the sintered samples had a homogeneous microstructure．Key words ：tape casting ；Y 3Fe 4．85O 12ferrite substrates ；rheological property收稿日期：2011-12-23；修订日期：2012-03-12基金项目：国防科工委项目作者简介：王科（1987-），男，浙江省人，硕士研究生。

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ElectrochemicalperformanceofspincoateddenseBaZr0.80Y0.16Zn0.04O3-dmembranes

IgorLuisettoa,b,c,SilviaLicocciaa,b,AlessandraD’Epifanioa,b,AlessandraSansond,ElisaMercadellid,ElisabettaDiBartolomeoa,b,

aDepartmentofChemicalScienceandTechnologies,UniversityofRomeTorVergata,ViadellaRicercaScientiﬁca1,00133Rome,Italy

bNASTCentre,UniversityofRomeTorVergata,ViadellaRicercaScientiﬁca1,00133Rome,Italy

cDepartmentofMechanicalandIndustrialEngineering,UniversityofRomeTre,ViaVascaNavale79,00146Rome,Italy

dCNR-ISTEC,InstituteofScienceandTechnologyforCeramics,NationalResearchCouncil,ViaGranarolo64,Faenza,Italy

highlights0.80Y0.16Zn0.04O3-dbycitricacid-nitrateauto-combustionmethod.

󰀁C.

articleinfoArticlehistory:Received15May2012Receivedinrevisedform16July2012Accepted31July2012Availableonline9August2012Keywords:BZYelectrolyteZndopingSpin-coatingIT-SOFCabstractThehighsinteringtemperatureofYttriumdopedbariumzirconate(BZY),themostpromisinghightemperatureprotonconductor(HTPC)forIntermediateTemperature(400e750󰀁C)SolidOxideFuelCells

(IT-SOFCs),hasbeenreducedbyusingZnOasasinteringaid.Obtainingadenseelectrolyteatareducedtemperatureallowsconventionalfuelcellpreparationmethods.AreproduciblespincoatingmethodtofabricatehighlyperforminganodesupportedbuttoncellswithdensemicrometricBZYZnelectrolytelayershasbeendeveloped.Theelectrochemicalcharacterizationofbuttoncellsat600󰀁Cshowspromisingperformance,higherthanthatofcomparablefuelcellsfrom

literature.Ó2012ElsevierB.V.Allrightsreserved.

1.IntroductionHightemperatureprotonconductors(HTPCs)havebeenwidelyinvestigatedaspotentialelectrolytesmaterialsforIntermediateTemperature(400e750󰀁C)SolidOxideFuelCells(IT-SOFCs)[1e4].

Yttriumdopedbariumzirconate(BZY)hasemergedasappealingelectrolytebecauseofitshighconductivityandgoodchemicalstability[5e7].Itshighlyrefractorynaturehasdriveninvestiga-tionsonthedevelopmentofproperprocessingprotocolsaimingto

achievehigh-densityandlargegrainedmaterialatreasonablesinteringtemperatures,thusreducingcostsandimprovingtheoverallconductivity[8,9].Differentmethods,suchastheprepara-tionofBCY-BZYsolidsolutions[10e12],thesynthesisofultraﬁnepowders[13e15],theuseofsinteringaid[16e20]havebeenexploitedtoachievethisaim.Thereductionofthesinteringtemperatureallowsthefabricationofco-sinteredfuelcellsassuringenoughelectrodeporosityandreducingchemicalreactionsattheelectrodeeelectrolytesinterface.TheuseofZnOhasbeenextensivelyinvestigatedanddensitieslargerthan90%havebeenobtainedattemperaturesofabout1300e1450󰀁C,associatedwithaslightdecreaseofproton

conductivity[16,21e24].Theconsiderablylowersinteringtemperature,comparedtotheundopedBZY,makeBaZ-r0.80Y0.16Zn0.04O3-d(BZYZn)apromisingelectrolyteforthe

*Correspondingauthor.DepartmentofChemicalScienceandTechnologies,

UniversityofRomeTorVergata,ViadellaRicercaScientiﬁca1,00133Rome,Italy.Tel.:þ390672594495;fax:þ390672594328.E-mailaddress:dibartolomeo@uniroma2.it(E.DiBartolomeo).

ContentslistsavailableatSciVerseScienceDirectJournalofPowerSources

journalhomepage:www.elsevier.com/locate/jpowsour

0378-7753/$eseefrontmatterÓ2012ElsevierB.V.Allrightsreserved.http://dx.doi.org/10.1016/j.jpowsour.2012.07.136

JournalofPowerSources220(2012)280e285preparationofdenseelectrolytemembraneonporousanodewithconventionalfuelcellpreparationmethods.Severalpreparationmethodshavebeenexploitedforthepreparationofthinandthickprotonconductingmembranesuchastapecasting[25],electrophoreticdeposition(EPD)[26,27],pulsedlaserdeposition(PLD)[28],co-pressing[29,30],spraycoating[31],andslurryspincoating[32].Amongthem,slurryspincoatingisasimpleandcosteffectivemethodthatallowsthecontroloftheelectrolytesthicknessbyvaryingthecoatingcycles.Itcanbeusedforthedepositionofelectrolytesmembraneoverapre-sinteredporouscermetthusovercomingsomelimitsofotherpreparationmethodsmentionedabove,suchasdelaminationandcracksoccurringduringtheco-sinteringstepintheco-pressingandtape-castingmethods,therequirementofconductingsubstratesforEPD,andtheneedofﬂatandporesfreesubstratesforPLD.Aimofthisworkistosetupareproduciblespincoatingmethodtofabricateatlab-scalehighlyperforminganodesupportedbuttoncellswithdensemicrometricBZYZnelectrolytelayers,andtoinvestigatetheelectrochemicalperformancesandcomparingthemwithresultsfromliterature.

2.ExperimentalBaZr0.80Y0.16Zn0.04O3-d(BZYZn)perovskitespowderswere

preparedbyacitricacid-nitrateauto-combustionmethodaspreviouslydescribed[33,34].Greencermetanodeswerepreparedbydiepressingmethod:NiOnanometricpowders(SigmaAldrich)andBZYinaweightproportion60:40wereplanetarymilledinethanolsolventwithBUTVAR98(5wt%)(SigmaAldrich)asbinderfor4h.Next,micrometricgraphite(10wt%)(SigmaAldrich)wasaddedasporeformingagentandmilledforanotherhour.Theslurrywasdriedoverthenightat75󰀁Candgroundedinanagatemortarfor4or8h.