快速凝固热强A1—Ti—RE合金设计

以快速凝固A1—4Ti—2V—3La合金作为研究对象，研究合金的显微结构、热稳定性和力学性能。提出为改善Al-Ti—RE基热强合金的显微组织和性能的合金设计原则，应进一步多元化，其中Ni、Cr元素比较理想，它们与Ti的物理性质相近，在α—Al中有较高的极限固溶度和较低的平衡固溶度，在高温有较低的扩散速率，具有较高的表面张力，并能改善熔体的微观不均匀性。     

锂空气电池固体电解质Li_(1+x)Al_xTi_(2-x)(PO_4)_3的制备研究

以Li_2CO_3、Al_2O_3、TiO_2、NH_4H_2PO_4为原料,采用固相烧结法制备锂空气电池固体电解质Li_(1+x)Al_xTi_(2-x)(PO_4)_3(LATP),研究了不同x值、不同烧结温度对电解质性能的影响。通过X射线衍射仪(XRD)、扫描电镜(SEM)和电化学阻抗谱(EIS)对所制备电解质的结构与性能进行表征。结果表明在x值等于0.2时得到纯相的LATP,最佳烧结工艺是350℃保温2 h,600℃保温2 h,1 000℃保温8 h,室温下的电导率为4.89×10~(-5)S/cm。     

Preparation and electrochemical properties of Y-doped Li3V2（PO4）3 cathode materials for lithium batteries

Y-doped Li3V2(PO4)3 cathode materials were prepared by a carbothermal reduction(CTR) process. The properties of the Y-doped Li3V2(PO4)3 were investigated by X-ray diffraction (XRD) and electrochemical measurements. XRD studies showed that the Y-doped Li3V2(PO4)3 had the same monoclinic structure as the undoped Li3V2(PO4)3. The Y-doped Li3V2(PO4)3 samples were investigated on the Li extraction/insertion performances through charge/discharge, cyclic voltammogram (CV), and electrochemical impedance spectra (EIS). The optimal doping content of Y was x=0.03 in Li3V2-xYx(PO4)3 system. The Y-doped Li3V2(PO4)3 samples showed a better cyclic ability. The electrode reaction reversibility was enhanced, and the charge transfer resistance was decreased through the Y-doping. The improved electrochemical performances of the Y-doped Li3V2(PO4)3 cathode materials were attributed to the addition of Y3+ ion by stabilizing the monoclinic structure.     

Cu掺杂LiNi0.6Co0.2Mn0.2O2的电化学性能

采用共沉淀法制备前驱体,高温固相合成正极材料Li（Ni_0.6Co_0.2Mn_0.2）_1-xCu_xO₂（x=0、0.01、0.015和0.02）,通过X射线衍射、SEM和电池测试系统及电化学工作站测试,对其结构、形貌和电化学性能进行表征.结果表明,掺杂少量的Cu, 样品均具有α-NaFeO₂型结构,没有出现杂相; 样品（108）/（110）峰分裂明显,材料有着良好的层状结构;随着Cu掺杂量的增加,c和c/a增大,层间距增大,Li+脱嵌通道增大,改善导电性.Cu掺杂1 %和1.5 %的I_（003）/I_（104）比值分别为1.467、1.438,比0 %的1.431值大,减小了阳离子混排.首次放电比容量依次为170.6 mAh/g、164.1 mAh/g、163.6 mAh/g和162.4 mAh/g,当x为0,1 %,2 %经过100次循环,保持率为87.1 %、98.7 %、和87.7 %;x为1.5 %,比容量从161.8 mAh/g增加到173.9 mAh/g,性能较优.      

Synthesis, Structure and Ionic Conductivity of La2／3-x Li3x MoO4

AlargenumberofM0 .5A0 .5M′O4 (M :rareearthion ,Bi3+,Fe3+,Cr3+,etc .A :alkaliion ,Cu+,Ag+,etc .M′ :Mo ,W )withtetragonalscheelite typestructurehavegoodcatalyticproperties .Aslumines centsubstrates ,theyhaveexcellentsensitizationtolu minescenceofrareearthion .Manyresearchesontheirstructure ,catalytic ,magneticandluminescentproper tieshavebeenmadesince 196 0s[1～ 10 ] .Thegeneralformulaforcompoundswiththetetragonalscheelite typestructureisAM′O4 wherethecationM′istetrahe drallycoordinat…     

Preparation and Ionic Conductivity of Ultrafine Li2+xRExSi1-xO3 by Sol-Gel Method

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Effect of electron traps on long afterglow behavior of Sr3Al2O6:Eu0.012+,Dy0.02-x3+,Hox3+

The long persistent phosphors Sr3Al2O6:Eu0.012+,Dy0.02-x3+,Hox3+ (x=0, 0.01, 0.02) were prepared by a high temperature solid state reaction. All samples showed a broad band emission peaking at ~510 nm, which could be ascribed to Eu2+ transition between 4f65d1 and 4f7 electron configurations. With the increase of substitution of Ho3+ ions for the Dy3+ ions in the as-prepared phosphors Sr3Al2O6:Eu0.012+,Dy0.02-x3+,Hox3+ (x=0, 0.01, 0.02), the initial intensity of the afterglow obviously decreased. From the thermoluminescence (TL) curves of the samples, we concluded that codoped Ho3+ ions led to a decline of the trap depth and redistribution of the trap. This may be responsible for the change of afterglow of Sr3Al2O6:Eu0.012+,Dy0.02-x3+,Hox3+ (x=0, 0.01, 0.02).     

沉淀—胶溶法制备偏钛酸型锂离子交换剂研究

报道一种制备Li_2TiO_3的新方法—无机沉淀胶溶法。以硫酸氧钛为钛源、乙酸锂为锂源、过氧化氢为络合剂,经沉淀-胶溶制备钛-锂溶胶体系,再经干燥、煅烧、酸洗制备偏钛酸型锂吸附剂。采用FTIR、TG-DSC、XRD、SEM、ICP、Zetasizer Nano及旋转式黏度计等测试、表征手段,考察了各制备条件对溶胶体系稳定性、干凝胶及Li_2TiO_3显微结构特性及性能的影响。结果表明:乙酸锂为锂源,体系pH值为7,Ti~(4+)浓度为0.2 mol/L,经陈化24h,可得到黏度为7.3 m Pa·s,Zeta电位为-29.5 m V的稳定溶胶体系。红外光谱分析表明干凝胶中含过氧键;干凝胶较佳煅烧温度和煅烧时间分别为750℃、2 h,制备得到β-Li_2TiO_3,;将β-Li_2TiO_3用0.2 mol/L盐酸溶液进行酸洗制备得到偏钛酸型锂吸附剂H_2TiO_3,锂的酸洗率为85.31%,锂的再吸附容量为27.15 mg/g。     

Li, Co共掺杂ZnO纳米颗粒的结构和磁性研究

利用溶胶-凝胶法制备了不同组分的Zn_(0.95-x)Co_(0.05)Li_xO纳米颗粒, 并通过透射电子显微镜、 X射线衍射、紫外-可见吸收光谱和振动样品磁强计对其结构和磁性进行了系统的研究. 结果表明, 当Li掺杂比例在7%以下时, Zn_(0.95-x)Co_(0.05)Li_xO纳米颗粒仍具有很好的ZnO六角纤锌矿结构, 但随着Li掺杂量的增加, 晶格常数a和c值略有减小; Zn_(0.95-x)Co_(0.05)Li_xO的室温铁磁性随x的增大而显著增强. 当Li掺杂量达到9%时, 在Zn_(0.95-x)Co_(0.05)Li_xO纳米颗粒的XRD谱中检测出第二相的LiCoO_2団簇, 样品的铁磁磁化强度明显下降. 表征结果显示Li掺入Zn_(0.95)Co_(0.05)O的反应过程可以分为3个阶段. 前两个阶段分别在材料中引入了Li′_(Zn)深能级缺陷和Li~+填隙离子, 第三个阶段则产生了LiCoO_2第二相结构. 样品铁磁性的变化与Li掺杂引入的这些缺陷和第二相有关, 可由束缚磁极化子(BMP)模型解释.     

New Zincophosphite with Infinite One-dimensional [Zn(HPO3)(H2PO3)]- Chains: Synthesis, Characterizations and Spectral Properties

With dimethylamine as a template, a new one-dimensional zincophosphite (C2H8N)·[Zn(HPO3)(H2PO3)]was prepared under hydrothermal conditions and characterized by single-crystal X-ray diffraction, FTIR spectrametry, elemental analysis, powder X-ray diffraction, and thermogravimetric analysis. The compound crystallized in the Monoclinic space group P2(1)/c, with cell parameters, a=0.78410(9)nm, b=1.54744(2)nm, c=0.81418(1) nm, β=105.8150(1)°, V=0.95049(2) nm3 and Z=4. The connectivity of the ZnO4 tetrahedron and HPO3 pseudo pyramid resulted in inifinite corner-sharing 4-membered ring chains, which were further linked by the protonated amine molecules to form a 3D structure via hydrogen bonds. To the best of our knowledge, this is the first existence of a zincophosphite with the anionic framework composition of [Zn(HPO3)(H2PO3)]-. The compound exhibits intense photoluminescence at room temperature.     

钙钛矿型锂离子固体电解质Li2x?ySr1?xTi1?yNbyO3的性能

采用高温固相法成功制备了Li_2x?ySr_1?xTi_1?yNb_yO₃ (x=3y/4, y=0.25, 0.5, 0.6, 0.7, 0.75, 0.8)锂离子固体电解质,并通过X射线衍射（XRD）、扫描电子显微镜（SEM）、交流阻抗图谱、恒电位极化等分别研究了各个组分的晶体结构、微观形貌、离子电导率和电子电导率。XRD显示当y≤0.70时,材料为立方钙钛矿型结构,几乎没有杂质相生成。SEM表明随着掺杂含量的增加材料的晶粒尺寸逐渐增大。Li_0.35Sr_0.475Ti_0.3Nb_0.7O₃锂离子固体电解质有着高离子电导率,为3.62×10?5 S·cm?1,其电子电导率为2.55×10?9 S·cm?1,活化能仅为0.29 eV。使用以Li_0.35Sr_0.475Ti_0.3Nb_0.7O₃为隔膜的LiFePO₄/Li半电池经过100圈循环后,放电比容量仍有93.9 mA·h·g?1,容量保持率为90.72%。