纳米级Li2+xLaxSi1-xO3的溶胶-凝胶法合成及电导性能

以无机盐和金属醇盐为前驱物,用溶胶－凝胶法制备了Ｌｉ２＋ｘＬａｘＳｉ１－ｘＯ３（ｘ＝０－０．１５）,用ＩＲ,ＤＴＡ－ＴＧ,ＸＲＤ,ＴＥＭ及交流阻抗等技术对样品的结构、组成相的形貌、粒径及烧结体离子导电性等进行了观测。结果表明：其固溶体形成范围是０〈ｘ≤０．０５;平均粒径为７０ｎｍ;在固溶体范围内,样品电导率随掺杂量增加而增高;与传统的固相合成方法相比,该法可使样品的生成温度降低,离子导电性得到提高     

热处理工艺对Al-Li合金冲击性能的影响

采用不同的热处理工艺 ,研究了 Al- L i合金的组织及常温、低温冲击韧度。     

Li3VO4离子导体材料的合成及其离子导电性

用柠檬酸盐深胶－凝胶法和传统的固相方法分别合成了Ｌｉ３Ｖｏ４音相。产物的粉末和烧结体应用ＤＴＡ－ＴＧ,ＸＲＤ,ＴＥＭ,ＳＥＭ及交流阻抗谱技术进行了表征和比较,实验结果表明,与传统的固相反应方法相比,用柠檬酸盐深胶凝胶法合成Ｌｉ３ＶＯ４所需温度约低３５０℃,并物的离子导电性上数量级,粉体粒径在８０ｎｍ以下,在１５～６００℃温度范围内,产物烧结体的离子电导率为１０＾－８～１０＾－４Ｓ．ｃｍ＾－１。     

Accessibility of lithium cations in high-silica zeolites investigated using the NMR paramagnetic shift effect of adsorbed oxygen

The accessibility of lithium cations in the high-silica zeolites ZSM-5 and beta was investigated using ⁷Li MAS NMR spectroscopy. The samples are investigated in vacuum and in the presence of adsorbed oxygen molecules. The paramagnetic shift effect due to the oxygen molecules was exploited to determine the fractions of accessible lithium cations. Approximately 85% of lithium cations in Al-ZSM-5 (Si/Al=50) are accessible to oxygen molecules, while none of the cation sites in zeolite Al-beta (Si/Al=18 and 8) and only a small fraction in B-beta (Si/B=15) were available for adsorption. This difference indicates a very distinct coordination environment for Li⁺ in zeolite beta as compared to ZSM-5.     

80MPa高强度自流平混凝土的研究与应用

根据试验分析了高强度自流平混凝土配制特点 ,研究了锂渣、磨细矿渣、硅粉掺合料对高强度自流平混凝土强度和流展度的影响 ;分析了锂渣掺合料提高混凝土强度和流展度的机理 ,并将 80MPa的高强度自流平混凝土成功地应用于清华大学主楼部分柱子的加固。     

Enhancement of hydrogen storage properties of metal-organic framework-5 by substitution (Zn,Cd and Mg) and decoration (Li,Be and Na)

Two strategies of decoration by three elements Z = Li, Be and Na in cyclic site, and substitution of Zn by Mg and Cd in unit cell were used in the framework of functional density theory to tune the hydrogen storage properties of metal-organic framework-5 (MOF-5) based on Zn whose decomposition temperature and initial gravimetric capacity are 300 K and 1.57 wt% respectively.Based on the adsorption of hydrogen molecules in the crystal surface at three different adsorption sites with three orientations of H₂, we show that our system may reach a maximum gravimetric storage capacity of 4.09 wt% for multiple hydrogen molecules. Moreover, the functionalization of Z combined to the substitution, shows an exceptional improvement of hydrogen storage properties. For example, Mg-MOF-5 decorated with Li₂ has a capacity up to 5.41 wt% and 513 K as desorption temperature.     

Kalman filter for adaptive learning of look-up tables with application to automotive battery resistance estimation

In online automotive applications, look-up tables are often used to model nonlinearities in component models that are to be valid over large operating ranges. If the component characteristics change with ageing or wear, these look-up tables must be updated online. Here, a method is presented where a Kalman filter is used to update the entire look-up table based on local estimation at the current operating conditions. The method is based on the idea that the parameter changes observed as a component ages are caused by physical phenomena having effect over a larger part of the operating range that may have been excited. This means that ageing patterns at different operating points are correlated, and these correlations are used to drive a random walk process that models the parameter changes. To demonstrate properties of the method, it is applied to estimate the ohmic resistance of a lithium–ion battery. In simulations the complete look-up table is successfully updated without problems of drift, even in parts of the operating range that are almost never excited. The method is also robust to uncertainties, both in the ageing model and in initial parameter estimates.     

GH2909合金产品局部宏观成分偏析形成原因探讨

通过对GH2909合金宏观成分偏析现象进行宏微观形貌观察、成分分析、重新取样检测及生产过程情况调查,得出：宏观成分偏析是局部的,并产生于真空电弧重熔过程中;由于将电流给定值由6800A提升到7000A,打破了正常重熔瞬间平衡,造成熔速和溶池形状剧烈波动而产生的。     

Electrical properties of LiNbO3 (electrolyte)/Cu (anode) bi-layers

In this work specific film structures of Li-Nb-O/Li/Li-Nb-O are investigated by AC Impedance Spectroscopy measurements at different temperatures. This gives the opportunity to investigate properties of the material itself and, at the same time, to consider the influence of the grain boundaries on the ionic behavior of the polycrystalline Lithium Niobate. On the other hand, LiNbO₃/Li/Cu multi-layers are studied as electrolyte/anode bi-layers and potential parts of “Li-free” microbatteries. The Li deficiency in the as deposited Li-Nb-O films is cured by forming a “sandwich” of Li-Nb-O/Li/Li-Nb-O, which after annealing becomes ionic conductor. The electrical behavior of an annealed film depends on two sources. The first is due to properties of the material itself and the second is based on the network of the grain boundaries. The average size of the grains is strongly influenced by the structure of the ohmic-contact/substrate. The electrical behavior of the electrolyte/anode interface of the “Li-free” structure LiNbO₃/Li/Cu/Au is very similar to the impedance measurements of the single LiNbO₃ single films. The whole multilayer structure, though, presents a third relaxation time which is consistent of a small resistance. This resistance is independent of temperature and it seems that is due to the metallic interface Li/Cu/Au.     

Customizing Multifunctional Sulfur Host Materials Via a General Anion-Exchange Process with Metal–Organic Solid

Fe/Co/Ni-based discrete nanoparticles are often explored to chemically adsorb and catalytically convert polysulfides for high-performance Li–S batteries. Herein, by manipulating the anion-exchange process between Ni–Co acetate microcrystals and various organic anions, porous single- or multi-layered hierarchically functionalized carbon nanoshells are customized. Among them, the shell-in-shell composite, namely C–NiCoPi@C–Ni₂Co, which has an external Ni₂Co-decorated carbon nanoshell and an internal Ni₃P-anchored carbon nanoshell encapsulated within a 3D-structured continuous NiCo-phosphate (NiCoPi) layer, displays collective merits as a sulfur host. Particularly, compared with discrete nanoparticles, the network-like NiCoPi layer is structurally and inherently advantageous in chemical adsorption and catalytic conversion of polysulfides, as also supported by Density Functional Theory calculations, while the metallic Ni₂Co nanoparticles enable high local conductivity. Such S@C–NiCoPi@C–Ni₂Co displays an initial specific capacity of 1237 mAhg^–1 at 0.1 C and maintains 1010 mAhg^–1 after 100 cycles; at 0.5 C, its discharge specific capacity in the 1st cycle is as high as 1038 mAhg^–1 and maintains capacity retention as high as 86% after 500 cycles. This study provides a straightforward strategy in customizing multifunctional sulfur hosts for high-performance Li–S batteries.