Sr和Nd掺杂对La9.33（SiO4）6O2电解质性能的影响

采用尿素-硝酸盐燃烧法对磷灰石型LSO电解质进行了三价稀土元素Nd和二价碱土元素Sr的La位掺杂,对合成样品进行XRD、SEM分析表征,并测试和分析了样品的电导率.结果表明:Sr、Nd掺杂对LSO的晶体结构、物相和形貌产生的影响很小,而适量的掺杂可有效提高LSO的氧离子传输性能.当掺杂x=0.3时,La9.33Mx(SiO4)6O2+δ(M=Sr、Nd)具有最高离子电导率,La9.33M0.3(SiO4)6O2+δ在500℃时的电导率分别为7.248×10-3S.cm-1、1.782×10-2S.cm-1.Nd掺杂不仅可以提高电导率,还可以降低传导活化能,相比于Sr掺杂更有利于LSO在中低温SOFCs中的应用.实验认为,Sr、Nd掺杂的LSO属于间隙氧传导机制,掺杂可以提高间隙氧的数量,间隙氧相比阳离子空位对LSO电导率的影响更大.     

SO42-/ZrO2-Nd2O3固体酸的制备及其催化活性

以皮胶原纤维为模板剂,硫酸锆为锆源,掺杂稀土Nd元素制备SO42-/ZrO2-Nd2O3固体酸。通过TG、XRD、FT-IR、SEM以及N2吸附脱附分析等表征了制备条件对SO42-/ZrO2-Nd2O3固体酸结构的影响。结果表明,SO42-/ZrO2-Nd2O3固体酸较好地保持了模板的纤维结构,添加稀土Nd元素能有效抑制晶粒增长,ZrO2-Nd2O3晶粒尺寸为5.1~11.6 nm,比表面积为63.96 m2/g;以乙酸和正丁醇的酯化反应为模型反应考察SO42-/ZrO2-Nd2O3固体酸的催化活性,催化剂活性较高,重复使用5次,乙酸的转化率仍可达到85%,表现出较好的重复使用性,具有一定的工业应用前景。     

SO42-/ZrO2-Al2O3固体超强酸催化合成苯甲酸乙酯

采用沉淀-浸渍法制备了SO42-/ZrO2-Al2O3,固体超强酸,研究了SO42-/ZrO2Al2O3固体超强酸催化苯甲酸与乙醇的酯化反应,结果表明最适宜的反应条件为锆铝摩尔比为l2,醇酸摩尔比为5,焙烧温度500～600℃,焙烧、反应各4 h,催化剂的用量为总量的6.64%.此外,还测定了含氯的固体酸的性能,比较了优化后的固体酸与浓硫酸催化性能.     

中温固体电解质Ce_(0.8)Gd_(0.2-x)Y_xO_(2-δ)(x=0,0.05,0.10)的制备与性能研究

用溶胶-凝胶法合成了固体电解质Ce0.8Gd0.2-xYxO2-δ(x=0,0.05,0.10).用X射线衍射谱、拉曼光谱分析了样品的微观结构,用交流复阻抗谱研究了样品的电学性能.结果表明:800℃焙烧的所有样品均为具有氧缺位的单相立方萤石结构,晶胞参数随钇(Y)掺杂量增加而减小.钇掺杂量x=0.05的样品Ce0.8Gd0.15Y0.05O2-δ的电导率最高,导电活化能最小,(σ700℃=5.58×10-3S·cm-1,Eα=0.92 eV),高于未掺杂Y的Ce0.8Gd0.2O2-δ样品的电导率(σ700℃=5.38×10-3S·cm-1Eα=1.09 eV).说明适量双掺杂Y提高了Ce0.8Gd0.2-xYxO2-δ的电导率并且降低了其活化能.     

钐和锌双掺杂La9.33（SiO4）6O2电解质的制备及其电导率

为提高磷灰石型电解质（LSO）的电导率,以氧化镧（La₂O₃）、氧化锌（ZnO）和氧化钐（Sm₂O₃）为主要原料通过尿素-硝酸盐燃烧法在600 ℃的温度下合成了掺杂钐和锌的La_9.33Sm_xSi₅ZnO_{（25+1.5x）}固体电解质粉末。采用X射线衍射、扫描电子显微镜、变温介电测量系统对样品进行物质结构、表面形貌、电导率的表征。研究了不同温度和不同掺杂浓度下La_9.33Sm_xSi₅ZnO_{（25+1.5x）}的电导率。结果表明,Sm和Zn成功掺杂进入LSO的晶格中,样品具有典型的P6₃/m磷灰石结构且纯度高,LSO的形貌未改变。当Sm掺杂浓度为0.6,Zn掺杂浓度为1时,在温度为650 ℃下La_9.33Sm_xSi₅ZnO_{（25+1.5x）}的电导率达到1.50×10^-3 S/cm;确定了最佳烧结温度为1 400 ℃。La_9.33Sm_xSi₅ZnO_{（25+1.5x）}的电导率在同一温度下随着掺杂量的增加先提高后降低,掺杂样品的晶胞参数相比于未掺杂样品的晶胞参数增大,活化能随着掺杂量的增大先降低后升高。此外La_9.33Sm_xSi₅ZnO_{（25+1.5x）}的电导率在同一掺杂量下,随着温度的升高而提高。     

中温氧化物燃料电池电解质材料制备和性能研究

中温固体氧化物燃料电池（SOFCs）的工作温度应低于800℃。本文重点对ZrO2基、CeO2基、Bi2O3基和ABO3型电解质材料的最新进展和发展趋势作了综述。以8%氧化钇稳定氧化锆（8YSZ）作为电解质的SOFCs,工作温度在1000℃左右。经较低价的碱土和稀土离子（Sr2＋,Ca2＋,Sc3＋和Y3＋）掺杂稳定ZrO2,在800℃,氧化钪掺杂氧化锆（Zr0.9Sc0.1O1.95,scandia doped zirconia,SSZ）的电导率（0.1S/cm）比Zr0.9Y0.1O1.95（10YSZ）的（0.03S/cm）高得多。薄膜化是改进氧化锆基电解质的电导性能的另一个途径。厚度小于10μm的YSZ基SOFCs,在800℃时功率密度最大可达2W/cm2。研究新的稳定的双掺杂电解质材料将会是CeO2基材料研究的重点。Y2O3和Sm2O3共掺杂（Y0.1Sm0.1Ce0.8O1.9,YSCO）在800℃时电导率可达到0.0549S/cm,电导活化能为0.77eV。Sr和Mg共掺杂LaGaO3（LSGM）阳离子导体已成为中低温SOFCs的重要候选电解质材料。钙钛矿型氧化物是除了Bi2O3以外氧离子电导率最高的陶瓷材料。寻求新的、优良的中温SOFCs电解质材料仍是目前推动中温SOFCs实用化的关键因素之一,薄膜化技术是研究的另一个重点。     

Gd_（2-x）Nd_xZr_2O_7烧绿石的高温高压快速合成

为了探索模拟三价锕系核素在Gd2Zr2O7基材中的快速固化方法,按照化学计量关系Gd 2-x Nd xZr2O7（x=0.42和x=0.86）设计配方,以Gd2O3,ZrO2和Nd2O3（Nd3＋作三价锕系核素替代物）粉体为原料,进行了高温高压合成实验。制备的样品通过X射线衍射分析和扫描电镜分析表明：在压力分别为3 GPa,3.5 GPa,4 GPa,温度为1 573 K,1 673 K条件下保温保压15 min,获得了单相烧绿石结构的Gd 2-x Nd xZr2O7致密烧结体。该方法可为锆基烧绿石陶瓷固化锕系核素提供一种快速高效的技术途径。     

碱土掺杂硅酸镧电解质材料的制备与性能

采用尿素-硝酸盐燃烧法在600～800℃下制备了较高纯度无杂质相的碱土掺杂磷灰石型La9.33Mx(SiO4)6O2+δ(M为Sr,Ca,Mg)电解质.通过X射线衍射、扫描电镜和交流阻抗测试,对样品的晶体结构、表面微观形貌及电导性能进行了研究.结果表明,燃烧合成的电解质粉体La9.33(SiO4)6O2(LSO)具有p63/m磷灰石型晶体结构;LSO烧结体的微观形貌随x值的不同而出现了细微变化;LSO烧结体具有良好的电阻可逆性和稳定性.适当的掺杂量能有效提高LSO的离子电导率,最佳掺杂浓度为0.2.相同掺杂量下,三种碱土金属阳离子掺杂对电导性能也有一定的影响,随着离子半径的增大,掺杂效果越来越好.     

改性WO3/ZrO2固体超强酸催化合成乙酰水杨酸

采用共沉淀法制备WO3/ZrO2及Ce、Mn改性WO3/ZrO2固体超强酸,通过XRD、Raman等方法对改性前后催化剂进行表征,并将其分别用于乙酰水杨酸合成反应考察催化性能,结果表明Ce改性WO3/ZrO2固体超强酸催化效果最好.以Ce改性WO3/ZrO2固体超强酸作为催化剂对乙酰水杨酸合成工艺进行优化,考察反应时间、反应温度、反应物配比及催化剂用量对酰化反应的影响.最佳反应条件下乙酰水杨酸收率达94.69％,且催化剂回收容易,重复使用多次仍具有较高活性.     

固态电解质LiZr2(PO4)3的掺杂及其在电极中的应用

NASICON型固态电解质磷酸锆锂(LZP)具有优异的结构稳定性和性能可靠性，但其在室温下的锂离子电导率较低，限制锂离子的传输。针对上述问题，采用溶胶凝胶法对磷酸锆锂电解质材料进行阳离子掺杂，提高材料的电导率，进而提升锂离子在材料中的输运能力。同时，将掺杂的磷酸锆锂电解质对电极进行修饰，提升电极本身的锂离子输运性能。探究了离子掺杂电解质对电极的锂离子扩散动力学性能的影响机理。实验结果表明，LiTi_0.25Zr_1.75(PO₄)₃对电极的锂离子扩散动力学性能提高最为显著，锂离子扩散系数达到3.25×10^-14cm²·S^-1,是未修饰电极的2.95倍，同时在5C倍率下，LiTi_0.25Zr_1.75(PO₄)₃修饰的电极比未修饰电极比容量提高了25.48 mAh·g^-1。     

Ca_xLa_(10-x)(SiO_4)_6O_(3-x/2)氧离子导体的制备及性能

由于在低温和低氧分压下具有比ZrO2固体电解质高的电导率,氧基磷灰石引起了研究者的关注.利用溶胶-凝胶法低温制备了硅酸盐磷灰石CaxLa10-x(SiO4)6O3-x/2 (x = 0, 0.5, 1.0 ,1.5和2),经TG-DTA、XRD、IR和SEM表征,所得产品为磷灰石相.以电化学阻抗谱研究了CaxLa10-x(SiO4)6O3-x/2的导电性能,发现随着间隙氧数量的增加,体系电导率逐渐增大,活化能却逐步减小.在700℃时La10(SiO4)6O3的电导率达到7.98×10-3Scm-1,比Ca2La8(SiO4)6O2提高21 000多倍.离子迁移数和氧分压对电导率的研究表明,主要的电荷载体是O2-,所制备的磷灰石为氧离子导体.     

Conductivity of (Zr1-xMx)O2 Ceramic

In the ZrO_2-based ceramic systems doped with different oxides (Y_(2)O_3, MgO and Al_(2)O_3), the behaviors of electronic and ionic conductivity have been investigated by the quantum chemical SCF-X_α-SW method. The results of the electronic energy spectra and local state density of atoms show that, for the ZrO_2 system doped with Al_2O_3, the energy gap near the Fermi energy level becomes smaller, which implies that the electronic conductivity increases. Since the binding energy between Al and O atoms is increased, the energy for oxygen vacancy migrating is enhanced and the ionic conductivity decreases. In the M_xO_y-doped ZrO_2 systems, due to the doping effect of Al_2O_3, MgO and Y_2O_3, the ionic conductivity increases successively, and the electronic conductivity decreases successively. The cal- culation results are in agreement with that of references and experience.     

Effect of ZrO2 （9mol % Y2O3） coating thickness on the electronic conductivity of Mg-PSZ oxygen sensors

The ZrO2 (9mol% Y2O3) coating was prepared evenly on the surface of MgO partially stabilized zirconia (Mg-PSZ) tube (oxygen sensor probe) by dipping the green Mg-PSZ tube in a ZrO2, (9mol% Y2O3) slurry and then co-firing at 1750℃ for 8 h. The double-cell method was employed to measure the electronic conductivity parameter and exam the reproducibility of the coated Mg-PSZ tube. The experimental results indicate that the good thermal shock resistance of the Mg-PSZ tube can be retained when the coating thickness is not more than 3.4μm. The ZrO2 (9mol% Y2O3) coating reduces the electronic conductivity parameter remarkably. probably due to the lower electronic conductivity of Y2O3-stabilized ZrO2 than that of MgO-stabilized ZrO2. Moreover, the ZrO2(9mol% Y2O3) coating can improve the reproducibility and accuracy of the Mg-PSZ tube significantly in the low oxygen measurement. The smooth surface feature and lower electronic conductivity of the coated Mg-PSZ tube should be responsible for this improvement.     

Effect of catalyst on structure of (PEO)8sLiClO4-SiO2 composite polymer electrolyte films

(PEO)8LiClO4-SiO2 composite polymer electrolytes(CPEs) were prepared by in-situ reaction, in which ethyl-orthosilicate (TEOS) was catalyzed by HC1 and NH3·H2O, respectively. The ionic conductivity, the contact angle and the morphology of inorganic particles in the CPEs were investigated by AC impedance spectra, contact angle method and TEM. The conductivities of acid-catalyzed CPE and alkali-catalyzed CPE are 2.2×10-5 and 1.1×10-5 S/cm respectively at 30 ℃. The results imply that the catalyst plays an important role in the structure of in-situ preparation of SiO2, and influences the surface energy and conductivity of CPE films directly. Meanwhile, the ionic conductivity is related to the surface energy.     

Thermal expansion properties and hygroscopicity of Y2-xSmxW3O12 (x = 0.0-0.4) compounds

A novel class of solid solutions of Y2-xSmxW3O12 (x = 0.0-0.4) were synthesized and studied by means of powder X-ray diffraction. All samples crystallize in an orthorhombic space group Pnca. The lattice parameters a, b and c of Y2-xSmxW3O12 increase with increasing Sm content. Since the compounds of this series hydrate at room temperature, thermogravimetric (TG) analysis was carried out. The result shows that the compound stores less water with increasing Sm content. The thermal expansion properties of Y2-xSmxW3O12 (x = 0.1, 0.3 and 0.4) were investigated with high temperature X-ray diffraction. Negative thermal expansion coefficient -α becomes less negative from -6.644×10-6 to -6.211×10-6℃-1 when x changes from 0.1 to 0.4.     

Synthesis and Characterization of (PEO)_x~-(V_(0.85)Mo_ (0.15)_2O_5 Nanocomposite Films

1　IntroductionSomeinorganiclayeredcompounds ,suchasMoO3 andV2 O5,belongtoarapidlygrowingfieldofcontempo raryresearchinterest,becausetheycanbeintercalatedbyavarietyofalkaliions (Li+ ,Na+ ,etc .) ,atomsorlargermoleculestoformintercalationhost guestcompounds ,whichareexpectedtobepromisingcandidatematerialsforcathodesofsecondaryLibatteriesandelectrochromicdevices[1] .Polymer layeredoxidenanocompositesareat tractingmuchattentionduetotheirspecialstructureaswellassuperiorelectrical,electrochemical…     

高岭土掺杂NASICON固体电解质及全固态电池性能

针对LiTi2(PO4)3基固态电解质电导率低的问题,采用浙江三门高岭土矿作为主要原料,以高温固相法制备铝、镁、硅共掺杂钠超离子导体(NASICON)型快离子导体Li1+2x+2yAlxMgyTi2-x-ySixP3-xO12.研究掺杂比例、温度对固态电解质离子电导率的影响.结果表明,组成为Li1.8Al0.1Mg0.3Ti1.6Si0.1P2.9O12固体电解质在423 K时有最高离子电导率7.86×10-4 S·cm-1.以该组成固态电解质为基片,喷雾热解原位制备Al/ Li1+xV3O8/ Li1.8Al0.1Mg0.3Ti1.6Si0.1 P2.9O12 /C全固态电池并在1.8～3.9 V电压区间进行50次充放电测试.该电池具有较好的稳定性及循环容量保持能力.30次循环以后放电容量基本稳定在190～205 mAh·g-1之间,充放电效率大于90%.