Na2O加入量对Li2O-ZnO-SiO2微晶玻璃性能的影响

文章研究了向Li2O-ZnO-SiO2微晶玻璃中加入Na2O,以降低其软化温度和高温熔体粘度,使其能用作金刚石砂轮结合剂.研究结果表明:当向Li2O-ZnO-SiO2微晶玻璃中加入Na2O时,Na2O降低Li2O-ZnO-SiO2微晶玻璃软化温度的作用不十分明显,加入量达12.94%(mol%)时,玻璃的软化温度仍有1263K(仍高于金刚石磨料要求烧成温度低于1173k的要求),而此时玻璃的热膨胀系数已达到14.7×10-6(远高于金刚石磨料的热膨胀系数3.17×10-6),同时微晶玻璃的结构遭到破坏,微晶玻璃的的抗折强度也随Na2O加入量的增加而降低.因此,Na2O应与其它低熔物共同作用才能改善Li2O-ZnO-SiO2微晶玻璃性能,使之能用作金刚石砂轮结合剂.     

ZrO2对Li2O-Al2O3-SiO2微粉析晶行为的影响

采用高分子网络凝胶法成功地制备出Li2O-Al2O3-SiO2-ZrO2(LASZ)微晶玻璃粉,探讨了添加不同含量ZrO2对LASZ微晶玻璃的析晶行为和相转变的影响.研究表明:热处理温度在700～1200 ℃时,LASZ微粉先形成六方晶系的β-石英固溶体,随热处理温度的升高,逐渐转变为稳定的四方晶系β-锂辉石固溶体.ZrO2含量增加,降低了β-石英固溶体的结晶温度,延迟了β-石英固溶体向β-锂辉石固溶体的转变.当ZrO2的物质的量分数从0增加到4.0%时,析晶活化能从304.6kJ/mol降低到248.9kJ/mol.所获得的LASZ粉末晶粒大小为20～60 nm,晶粒尺寸随温度的升高而增大,随ZrO2的增加而下降.本实验所制备的LASZ微晶玻璃的热膨胀系数为(4～14)×10-7/℃.     

Y2O3对高分子网络凝胶法制备Li2O-Al2O3-SiO2系微晶玻璃性能的影响

以丙烯酰胺、N,N'-亚甲基双丙烯酰胺、碳酸锂、硝酸铝和正硅酸乙酯为原料,采用高分子网络凝胶法成功地制备出多组分氧化物Li2O-Al2O3-SiO2(LAS)微晶玻璃超微粉末,并掺杂了稀土氧化物Y2O3.将粉体压制烧结得到微晶玻璃块体.用IR,XRD,SEM等测试手段研究了掺杂对微晶玻璃组织与性能的影响,测定了微晶玻璃的热膨胀系数.实验表明:Y2O3使微晶玻璃的相变温度降低到900℃;掺杂后微晶玻璃的粒径减小;高分子网络凝胶法制备的Li2O-Al2O3-SiO2(LAS)微晶玻璃热膨胀系数达到10-7数量级,掺Y2O3使Li2O-Al2O3-SiO2(LAS)微晶玻璃的热膨胀系数提高.     

烧结法制备Li2O-Al2O3-SiO2微晶玻璃的烧结制度及性能研究

采用烧结法制备了Li2O-Al2O3-SiO2(LAS)微晶玻璃。通过DSC分析，并结合对LAS微晶玻璃烧结过程的研究，提出了其较合适的烧结制度。用XRD对该微晶玻璃的物相组成进行了研究，讨论了烧结温度对LAS微晶玻璃热膨胀系数及抗弯强度的影响。为获得具有结构均匀致密、晶相含量高的LAS微晶玻璃，应使烧结温度尽量接近主晶相析晶温度。本文研究的LAS微晶玻璃的适宜烧结温度为1130℃。     

Li取代对LAS系微晶玻璃核化行为的影响

以Li2O-Al2O3-SiO2三元系(LAS)微晶玻璃为研究对象,采用DTA、XRD等测试技术研究了不同Li2O含量LAS玻璃的核化行为,分析了Li取代对LAS玻璃核化行为的影响。研究结果表明,随着Li含量的降低,LAS系玻璃的相转变温度、析晶峰温度逐步增大,最佳核化温度逐渐升高,最佳核化时间没有明显的变化。     

ZnO取代部分Al2O3的Li2O-Al2O3-SiO2系微晶玻璃的相变和性能

研究了以质量分数（下同）0～15%的ZnO取代Li2O-Al2O3-SiO2玻璃体系中相等质量的Al2O3后,微晶玻璃相变和性能。结果表明：随ZnO的取代量的增加,玻璃的熔化温度和玻璃晶化峰温度及转变温度不断降低,所有成分的微晶玻璃均可以得到具有细小等轴晶粒的组织结构,材料的热膨胀系数较低。当ZnO的取代量为5％时,首先析出的晶相仍为β-石英固溶体;随温度升高β-石英固溶体转变为β-锂辉石固溶体,与未取代时几乎一样,组织和性能的变化也较小。当ZnO的取代量增加到10％时,820℃高温晶化后,除了析出了β-石英固溶体、β-锂辉石固溶体外,还出现了硅锌矿相,使材料有较好的热性能和力学性能。当ZnO的取代量增加到15％时,材料的晶粒易粗化,抗弯强度和断裂韧性下降。     

稀土La2O3对Li2O-A12O3-SiO2微晶玻璃结构和性能的影响

本主要研究添加微量稀土La2O3对Li2O-Al2O3-SiO2微晶玻璃晶相组成，显微结构，抗折强度的影响，研究结果表明：添加微量La2O3有利于Li2O-Al2O3-SiO2微晶玻璃中的主晶相β－锂辉石发育成完整的柱状，板状晶体，提高了微晶玻璃的抗折强度。     

封接用Li2O—ZnO—Al2O3-SiO2玻璃析晶和热膨胀行为研究

以传统熔融冷却法制得了Li2O-ZnO-Al2O3-SiO2(LZAS)系统无色透明的基础玻璃,通过热处理获得了与4J 29可伐合金封接用微晶玻璃材料.运用DTA、XRD等手段分析了组成和热处理制度对玻璃析晶和热膨胀行为的影响.结果表明,随ZnO取代(SiO2+Al2O3),NBO/T逐渐增大,第1、第3放热峰向低温方向偏移,第2放热峰则稍向高温方向偏移;对于24.5Li2O-15ZnO-8.55Al2O3-51.25SiO2-0.7P2O5系统玻璃来说,晶化温度对析出晶相的种类和含量影响显著,随晶化温度的升高,晶相变化表现出如下趋势:主晶相由方石英向Li2Al2Si3O10转变,次晶相由βⅡ/-Li2ZnSiO4向γ0-Li2ZnSiO4转变.这种变化也反映在热膨胀行为上,即随晶化温度升高,热膨胀系数在(40.2～123.6)×10-7/K之间变化.经535℃, 2h和700℃, 2h处理后获得的热膨胀系数为49.5×10-7/K,可满足与4J 29可伐合金封接使用要求.     

玻璃组成对Li2O-Al2O3-SiO2系统微晶玻璃膨胀系数的影响

以Li2O-Al2O3-SiO2系统微晶玻璃的标准样的组成为基础配方,改变玻璃组成中各种氧化物的含量,采用传统的熔融法制备了Li2O-Al2O3-SiO2系统微晶玻璃,利用SEM、XRD、DTA及热膨胀系数测定等分析手段,重点研究了玻璃组成中Li2O、Al2O3、SiO2的含量对微晶玻璃热膨胀系数的影响.研究结果表明:在标准试样的基础上,改变Li2O的含量,对热膨胀系数影响很大;热膨胀系数随Al2O3含量增大而增大,而SiO2含量的变化,对热膨胀系数影响不大.     

玻璃组成对Li_2O–Al_2O_3–SiO_2微晶玻璃热膨胀系数的影响(英文)

通过传统熔融法制备了具有低膨胀系数的Li2O-Al2O3-SiO2(LAS)微晶玻璃.利用扫描电镜、X射线衍射、差热分折及热膨胀系数测定等分 析手段,研究了玻璃组成中Li2O,Al2O3,SiO2的含量对微晶玻璃热膨胀系数的影响.结果表明:在标准样品的基础上,Li2O的含量对热膨胀系数影 响很大:Li2O的含量提高,由于形成β-锂辉石,微晶玻璃的结晶程度增加与晶粒尺寸增大,导致热膨胀系数增大.与此相比较,Al2O3和SiO2成分 的变化对膨胀系数的影响较小.当玻璃组成(质量分数,下同)为4%～6%Li2O,16%~18%Al203,66%~68%Si02时,Li2O-Al2Oy-SiO2玻璃的膨胀 系数为-1.5～1.5×10-7/℃(0~700℃)     

Low Li2O content study in Li2O-Al2O3-SiO2 glass-ceramics

The price of lithium-containing minerals and other chemical materials continues to increase, resulting in an increase in the production cost of Li₂O-Al₂O₃-SiO₂ (LAS) system glass-ceramics. In the LAS glass-ceramics component, the reduction in the amount of Li₂O used can reduce the cost of the product. It is worthwhile to study whether it is possible to prepare glass-ceramics with low expansion properties under low Li₂O content. The effect of Li₂O content on the glass-ceramics of LAS system was studied. In this paper, spodumene was used as the main raw material, and TiO₂ and ZrO₂ were added as crystal nucleating agents to prepare transparent glass-ceramics with low expansion coefficient. The effects of the change of Li₂O content on the crystal phase and microstructure of glass-ceramics were investigated by XRD, DSC, FTIR and SEM. The results show that the main crystalline phase of the low expansion transparent glass-ceramics is β-quartz solid solution. When Li₂O content is in the range of 2.99 wt% to 4.13 wt%, low expansion glass ceramics can be prepared by an appropriate method. With the increase of Li₂O content, the average coefficient of thermal expansion (CTE) in the temperature range of 30 °C–300 °C shows a decreasing trend. When Li₂O content is in the range of 3.51 wt% to 4.13 wt%, the thermal expansion coefficient of the glass ceramics is extremely small, and even a negative expansion coefficient occurs.     

Li2O-CuO-P2O5玻璃的电性能

本文采用一种新的成形工艺制备20Li2O-30CuO-50P2O5(摩尔比)玻璃,并在玻璃转变温度之上对样品进行了不同时间的热处理后测试了其电性能。结果发现,随热处理时间的延长电导率会出现峰值,且所有样品电导率与温度之间的关系都能很好地遵从Arrhenius关系,结合SEM、XPS和XRD分析,对这一现象作出了初步的解释。     

ZrO_2包覆富锂正极材料Li[Li_(0.2)Ni_(0.2)Mn_(0.6)]O_2

采用共沉淀-高温固相法制备了富锂正极材料Li[Li0.2Ni0.2Mn0.6]O2,并使用Zr(OC3H7)4进行了Zr O2包覆改性。通过X射线粉末衍射(XRD)、透射电子显微镜(TEM)和电化学测试手段讨论了Zr O2包覆对材料的结构、形貌和电化学性能的影响。Zr O2能均匀覆盖在Li[Li0.2Ni0.2Mn0.6]O2颗粒表面,包覆后材料的电化学性能有一定的改善。包覆质量分数0.5%的Zr O2样品表现了提高的循环和倍率性能。首次放电容量(0.1 C,2.0~4.8 V)高达250.8 m Ah·g-1,循环45周(0.2C)容量保持为201.6 m Ah·g-1,2.0 C倍率放电容量可达123.2 m Ah·g-1。     

Effect of Li2O excess in Li6.4Ga0.2La3Zr2O12 electrolyte for all-solid-state Li-ion batteries

Li₇La₃Zr₂O₁₂ is a promising material used as solid electrolyte in all-solid-state lithium batteries. However, the lithium ionic conductivity of LLZO is limited, and the cycling stability of lithium symmetric battery based on LLZO is not good. In this research, different Ga-doped LLZO samples were prepared by adding different excess amounts of Li₂O, and the effect of excess amount of Li₂O on the structure and performance of LLZO have been researched. The results show that with the rise of the amount of Li₂O, the lithium ionic concentration increases gradually, and the lithium ionic conductivity and the ratio of grain resistance to total resistance rise first and then drop. When the excess amount of Li₂O is 10 wt.%, the sample exhibits the highest lithium ionic conductivity of 1.36 mS/cm, and the lithium symmetric battery exhibits the most stable operation.     

Effect of Li2O on the crystallization behavior of CaO-Al2O3-SiO2-Li2O-Ce2O3 mold slags

The effect of Li₂O on the crystallization properties of CaO-Al₂O₃-SiO₂-Li₂O-Ce₂O₃ slags was investigated. With increasing the Li₂O content, LiAlO₂ and CaCeAlO₄ were the main crystalline phases. LiAlO₂ formed for the charge compensating of Li⁺ ions to [AlO₄^5?]-tetrahedrons, and CaCeAlO₄ formed as a result of the charge balance of Ce³⁺ ions, Ca²⁺ ions, and [AlO₆^9?]-octahedrons. Increasing the content of Li₂O to 10%, the crystallization temperature was the highest, and the incubation time was the shortest. The crystallization ability was strong due to the three factors of strengthening the interaction between ions and ion groups, decreasing the polymerization degree, and increasing the melting temperature. Further increasing the content of Li₂O, the crystallization performance was obviously suppressed, because the melting temperature and the force between the cations and the anion groups decreased.     

Crystallization of Li2O-Al2O3-SiO2 amorphous chemical mixtures

Li₂O·Al₂O₃·(4-10)SiO₂ chemical mixtures, synthesized by sol-gel technology, are analyzed using quantitative x-ray phase and parametric unit cell techniques and compared with glasses of identical composition. Specific features involved in the crystallization of chemical mixtures and glasses are discussed.Translated from Steklo i Keramika, No. 11, pp. 8–10, November, 1996.     

Li2O—La2O3—Ta2O5—SiO2电极玻璃的成分与性能

在Ｌｉ２Ｏ２４￣２８％、Ｌａ２Ｏ３ ４￣７％,ＳｉＯ２ ６５￣７０％（摩尔分数）的电极玻璃中加入１￣４％Ｔａ２Ｏ５,玻璃的密度、软化点、耐水性和电导率均随Ｔａ２Ｏ５含量的增加而提高,对含Ｔａ２Ｏ５玻璃性质与结构的关系进行了讨论。     

Li2B4O7-Bi2O3-WO3玻璃的光学性能研究

采用熔融淬冷方法制备了(100-x)Li2B4O7-x(Bi2O3·WO3)(5≤x≤20)玻璃.采用比重计测定了玻璃密度,分光光度计测量了玻璃的吸收光谱,V棱镜折射仪测量了玻璃折射率.结果表明,随着Bi2 O3·WO3含量的增加,玻璃样品的密度和摩尔体积增大,而氧堆积密度减小;玻璃的吸收光谱中截止波长逐渐向长波方向移动,玻璃的间接跃迁光学带隙、Urbach能和费米能逐渐减小,折射率增大.光学性能的变化和玻璃网络中部分桥氧转变为非桥氧有关.     

Structure and electrical conductivity of Li2O-B2O3 glasses

The temperature-concentration dependence of the electrical conductivity of Li₂O-B₂O₃ glasses in the temperature range of ～180–310°C has been studied. For pure boron anhydride, the dependence logσ = f([1/T]) is linear, whereas for glasses with ～2 mol % ≤ [Li₂O] < ～10 mol %, similar curves are kinked. At higher Li₂O concentration the kinks disappear. Occurrence of kinks is attributed to variation of essence of current carriers from proton pattern for B₂O₃ to mixed proton-ion pattern for low-alkali glasses. Conductivity of glasses at [Li₂O] ≥ 20 mol % is stipulated by the formation of a continuous sublattice of polar structuralchemical entities (entities) [BO_4/2]^?Li⁺ and the migration of lithium ions.