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Low Temperature Thermodynamic Study of the Stable and Metastable Phases of Silver

X.B. Li , Y.Q. Xie , Y.Z. Nie , H.J. Peng , null , null

金属学报(英文版)

The low temperature thermodynamics of the stable phase of silver was assessed by the polynomial model and Debye model from the experimental data available in the literature. By means of the constrained non-linear least squares curve fitting arithmetic, two sets of parameter values were determined. The expression of the thermodynamic functions cp(T) and G(T)-H (298.15K) at 0-298.15K were presented. Only the low temperature thermodynamics of the metastable phase of silver can be extrapolated by the Debye model. The expression of the thermodynamic functions cp(T) at 0-298.15K was presented.

关键词: silver , null , null

A STUDY OF TEMPERATURE-DEPENDENT VALENCE BOND STRUCTURE OF TITANIUM

X.B. Li

金属学报(英文版)

On the basis of energy and shape method for the determination of the valence bond (VB) structures of crystal, the valence bond structure of titanium is redetermined at room temperature and calculated in the whole temperature range of 0-1943K. The outer shell electronic distribution of Ti is ec2.9907 · (sc0.4980 + dc2.4927) ef1.0093 in crystal. The temperature dependences of the VB structures of hcp and bcc phases are the same. The VB structures of hcp and bcc phases monotonically increase or decrease with the increase in temperature, but show discontinuous changes at the phase-transformation temperature 1155K.

关键词: valence bond structure , null , null

Preparation of Li-B alloy and study of its microstructure and discharge characteristics

Zhijian LIU , Zhiyou LI , Wei DUAN , Xuanhui QU , Baiyun HUANG , Siqi ZHANG

材料科学技术(英文)

A LI-B alloy has been prepared using a pretreated amorphous B powder and pure Li ingot as starting materials by continually slow addition of B powder and intensified stirring in the process of melting. The microstructure and the discharge characteristic of the materials have been investigated. Results show that the problem of temperature control in synthesis would be modified by means of continual addition of B powder, the Li7B6 would be more finery distributed in the metal Li by means of intensified stirring. The discharge characteristic of the Li-B alloy using amorphous B as starting materials is almost the same with that of using crystalline B.

关键词:

Li-B合金的制备及反应机制研究

许小静 , 段柏华 , 曲选辉 , 罗远辉

稀有金属材料与工程

通过对合成装置的温控、散热、搅拌桨叶片等进行有效改进,获得了300 g/炉的制备规模,制备出的合金性能均匀一致,其密度及抗拉强度分别为0.870 g/cm3,12.61 Mpa.同时,根据反应合成现象及XRD结果,分析了Li-B合金的反应机制及其动力学过程.

关键词: 热电池 , Li-B合金 , 阳极材料 , 制备 , 反应机制

Mechanical Alloying of Fe_(100-x) B_x

Lizhi CHENG , Wei FENG , Xinquan DONG , Kuichang BAI and Kaiyuan HE (Dept. of Materials Science and Engineering , Northeastern University Shenyang 110006 , China)

材料科学技术(英文)

The formation of nonequilibrium phase by mechanical alloying (MA) of Fe and B powders in a high energy vibration ball mill has been made for Fe100-xBx system with x=15. 30, 35, 45,55 and 70. By using the X-ray diffraction, magnetic measurement and M6ssbauer spectrummethods, it was revealed that the structure of the MA product varies with milling time and B contents.

关键词:

Effect of the impurity Li(x)Ni(1-x)O on the electrochemical properties of 5 V cathode material LiNi(0.5)Mn(1.5)O(4)

Journal of Alloys and Compounds

The formation of impurity Li(x)Ni(1-x)O when synthesizing spinel LiNi(0.5)Mn(1.5)O(4) using solid state reaction method, and its influence on the electrochemical properties of product LiNi(0.5)Mn(1.5)O(4) were studied. The secondary phase LixNi(1-x)O emerges at high temperature due to oxygen deficiency for LiNi(0.5)Mn(1.5)O(4) and partial reduction of Mn(4+) to Mn(3+) in LiNi(0.5)Mn(1.5)O(4). Annealing process can diminish oxygen deficiency and inhibit impurity Li(x)Ni(1-x)O. The impurity reduces the specific capacity of product, but it does not have obvious negative effect on cycle performance of product. The capacity of LiNi(0.5)Mn(1.5)O(4) that contains Li(x)Ni(1-x)O can deliver about 120 mAhg(-1). (C) 2011 Elsevier B.V. All rights reserved.

关键词: Lithium ion batteries;LiNi(0.5)Mn(1.5)O(4);Impurity Li(x)Ni(1-x)O;Electrochemical properties;lithium batteries;rate capability;spinel;performance

Mg-x Li-Al 变形镁合金微观组织与拉伸性能

许天才 , 彭晓东 , 张玺 , 陈元芳 , 姜军伟 , 陈洁

功能材料 doi:10.3969/j.issn.1001-9731.2014.07.013

利用光学显微镜(OM)、扫描电子显微镜(SEM)、X 射线衍射仪(XRD)分析了 Li 元素对 Mg-x Li-3Al 合金组织的影响,并用电子万能试验机测试合金的拉伸性能.结果表明,Li 含量的变化可以明显改变合金的相组成.当 m (Li)<5.7%(质量分数)时合金由单一α-Mg 相组成;Li 含量在5.7%~10.3%(质量分数)之间时,合金为α-Mg+β-Li 双相;m (Li)>10.3%(质量分数)时合金为单一β-Li 相.合金的塑性随 Li 含量的升高而增加,铸态 LA113合金的延伸率高达37.36%,但挤压态下合金强度随 Li 含量升高而降低,挤压态 LA53合金具有最佳抗拉强度,达到263.28 MPa.当 Li 含量升高,合金中的第二相粒子会出现 Al12 Mg17转变为 LiMgAl2.

关键词: 镁锂合金 , 铸态 , 挤压态 , 微观组织 , 拉伸性能

Phase relations of the system Li(2)O-Gd(2)O(3)-B(2)O(3) and the structure of a new ternary compound

Journal of Alloys and Compounds

The subsolidus phase relations of the system Gd(2)O(3)-Li(2)O-B(2)O(3) are investigated by means of X-ray diffraction (XRD) analyses. There are eight binary compounds and two ternary compounds in this system. The phase diagram comprises thirteen three-phase regions. The ternary compound Li(6)Gd(BO(3))(3) is refined from the powder XRD data by the Rietveld method. It has a monoclinic structure with cell parameters a=7.2277(2) Angstrom, b=16.5057(5) Angstrom, c=6.6933(2) Angstrom, beta=105.3737(10)degrees and space group P2(1)/c. The rationality of the Li(6)Gd(BO(3))(3) structure is examined by the Brown theory and IR spectra. (C) 2002 Elsevier Science B.V. All rights reserved.

关键词: oxide materials;rare earth compounds;X-ray diffraction;phase diagram

热电池阳极Li-B合金放电前后的微观特征

刘志坚 , 段伟 , 黄英华 , 李志友 , 曲选辉

功能材料

使用扫描电子显微境对放电前后的Li-B合金的微观特征进行了观察,对影响Li-B合金放电稳定性的主要因素进行了分析.结果表明,轧制后的Li-B合金为塑性好的Li包裹脆性的LiB粒子,在520℃放电后Li-B合金与电解质界面依然完整,在大电流(200mA/cm)短时间(12min)放充电后,金属锂被LiB和电解质分割,表现在断口上金属锂为细丝状.

关键词: 热电池 , Li-B合金 , 阳极

溶胶凝胶法制备Li4.5B0.5Si0.5O4-xLi2O导体材料及导电性能

陈汝芬 , 宋秀芹 , 冯子成

材料科学与工艺 doi:10.3969/j.issn.1005-0299.2000.03.018

采用溶胶-凝胶法制备了Li4.5B0.5Si0.5O4-xLi2O(x=0~ 0.5)离子导体材料,并采用DTA-TG、XRD、TEM及交流阻抗等技术对样品进行了分析和测试 ,结果发现:溶胶-凝胶法可降低Li4.5B0.5Si0.5O4的合成温度;随Li 2O的掺入可增强基质材料的致密性并提高其离子的导电性能.

关键词: Li4.5B0.5Si0.5O4 , Li2O , 离子导电性 , 溶胶-凝胶法

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