壳聚糖/聚乙烯醇/三聚磷酸钠三元复合微球的制备及表征

由壳聚糖（ＣＳ）、聚乙烯醇（ＰＶＡ）和三聚磷酸钠（ＴＰＰ）制备了壳聚糖／聚乙烯醇／三聚磷酸钠三元复 合微球,探讨了体系中壳聚糖含量对复合微球的影响,以及离子种类及浓度和ｐＨ值对复合微球溶胀度的影 响。采用ＸＲＤ、ＦＴＩＲ和ＳＥＭ等测试技术对微球的组分、结构和形貌进行了表征。结果表明,ＣＳ和ＰＶＡ具有良好的相容性,随着ＣＳ含量的增加,ＰＶＡ的结晶性逐渐降低,复合微球的粒径约为４００～９５０ μｍ,表面较为粗糙;随着ＣＳ添加量的增加,凝胶平衡溶胀度先增大再减小,ＣＳ／ＰＶＡ／ＴＰＰ复合微球在ｐＨ值为３～8的溶胀度最大,且在同一种溶液中,随着离子浓度的增加,其溶胀度明显降低;复合微球具有溶胀 收缩可逆性,显示ＣＳ／ＰＶＡ／ＴＰＰ复合微球是ｐＨ／离子敏感型凝胶,可为药物缓释系统提供实验和理论依据。     

离子色谱法测定食品添加剂三聚磷酸盐中的杂质含量

研究了离子色谱法检测食品添加剂三聚磷酸盐中杂质含量的分析方法。用NaOH梯度淋洗,流速为1.8 mL/min,成功地同时测定了三聚磷酸盐中的Cl- NO- 3 SO2- 4 磷酸盐 焦磷酸钠 三偏磷酸钠等杂质的含量。各杂质在检测条件下有很好的线性,所测杂质的相对标准偏差范围为0.22%-8.32%。采用AS11型阴离子色谱柱,样品测定的整个过程可在15 min内完成。实验结果表明,该方法具有分析时间短 线性范围宽 灵敏准确 试剂用量少等优点。     

三聚磷酸钠辅助水热合成制备氧化锌纳米片

以三聚磷酸钠为表面活性剂,采用水热合成法制备了氧化锌纳米片。采用场发射扫描电镜,透射电镜,紫外可见分光光度计和荧光光谱仪对氧化锌纳米片的显微结构和光学性能进行了表征,并对氧化锌纳米片的形成机理进行了探讨。结果表明：在220 ℃水热反应28 h可得到尺寸大约为600 nm × 500 nm × 50 nm(长×宽×高)结晶良好的六角形氧化锌纳米片,氧化锌纳米片对可见光的反射率超过90%,对紫外光的反射率小于20%,在395 nm附近均存在较强的紫外发射峰。氧化锌纳米片的形成是由于氧化锌晶体的正极面{001}晶面上显露的OH^-悬健部分被具有负电性的磷酸根取代,这种取代的发生,阻碍了溶液中的生长基元Zn(OH)₄^2-在该晶面上叠合,使得本应生长最快的(001)晶面生长受限,所以得到了片状的纳米氧化锌。     

Lithium Bonds in Lithium Batteries

Lithium bonds are analogous to hydrogen bonds and are therefore expected to exhibit similar characteristics and functions. Additionally, the metallic nature and large atomic radius of Li bestow the Li bond with special features. As one of the most important applications of the element, Li batteries afford emerging opportunities for the exploration of Li bond chemistry. Herein, the historical development and concept of the Li bond are reviewed, in addition to the application of Li bonds in Li batteries. In this way, a comprehensive understanding of the Li bond in Li batteries and an outlook on its future developments is presented.     

Lithium

Ohne Zusammenfassung     

三聚磷酸二氢铝与有机胺的插层反应特征

采用IR、XRD、SEM、EDS、DT-TG和滴定实验等技术手段研究主体三聚磷酸二氢铝(ATP)与客体甲胺、乙胺、正丙胺和正丁胺等有机胺的插层反应特性。 实验结果表明,ATP与甲胺、乙胺、正丙胺、正丁胺发生了化学反应,有机胺中的N与ATP层间-OH上的H形成配位键。 这些有机胺通过插层反应改变了ATP的酸性、层间距和热分解温度,但没有改变颗粒的层状形貌。 层间距从0.795 nm增大至1.71 nm,层间距d与有机胺的碳原子数Cn呈线性关系：d=0.229Cn+0.811,R2=0.9986。 有机胺分子链越长则越具有剥离倾向。     

Fast Lithium Ion Conduction in Lithium Phosphidoaluminates

Solid electrolyte materials are crucial for the development of high‐energy‐density all‐solid‐state batteries (ASSB) using a nonflammable electrolyte. In order to retain a low lithium‐ion transfer resistance, fast lithium ion conducting solid electrolytes are required. We report on the novel superionic conductor Li₉AlP₄ which is easily synthesised from the elements via ball‐milling and subsequent annealing at moderate temperatures and which is characterized by single‐crystal and powder X‐ray diffraction. This representative of the novel compound class of lithium phosphidoaluminates has, as an undoped material, a remarkable fast ionic conductivity of 3 mS cm^?1 and a low activation energy of 29 kJ mol^?1 as determined by impedance spectroscopy. Temperature‐dependent ⁷Li NMR spectroscopy supports the fast lithium motion. In addition, Li₉AlP₄ combines a very high lithium content with a very low theoretical density of 1.703 g cm^?3. The distribution of the Li atoms over the diverse crystallographic positions between the [AlP₄]^9? tetrahedra is analyzed by means of DFT calculations.     

定量的复合金属锂作为三维泡沫锂电极用于锂电池的研究

金属锂作为电池的负极材料具有极高的比容量和极低的氧化还原电位,能够显著提升电池的能量密度。然而,金属锂负极在实际应用中所面临的主要问题是锂枝晶、界面副反应和电极体积变化大的难题。在本文中,我们提出了一种通过将定量的金属锂与三维骨架进行复合形成三维泡沫锂负极的策略,并利用三维泡沫锂来抑制锂枝晶的生长和缓解电极的体积变化。因此,三维泡沫锂电极有利于金属锂负极的高效利用,并能借助其与平面锂箔相比更高的比表面积和更多的反应位点来提升电池的倍率性能。因此,通过采用三维泡沫锂,对称电池的循环寿命和倍率性能都得到了有效的提升。EIS数据结果表明,三维泡沫锂能够减小对称电池的电荷转移阻抗。而且,将三维泡沫锂作为负极组装的LTO全电池,与锂箔作为负极相比,循环1000周平均放电比容量从65 mAh·g^-1提升至121 mAh·g^-1。     

CS/TPP纳米微胶囊的制备及其载药性能

利用离子凝胶法, 以三聚磷酸钠(TPP)为交联剂, 由壳聚糖(CS)制备了CS/TPP纳米微胶囊. 用红外光谱仪、扫描电镜和粒径分析仪进行了表征, 并以牛血清蛋白(BSA)作为模型药物, 考察了所制备的CS/TPP纳米微胶囊的包载和缓释性能. 结果表明, CS/TPP纳米微胶囊的红外光谱相对于CS和TPP的红外光谱发生了很大变化, 说明CS和TPP通过正负电荷吸引聚合成囊; 粒径分析表明, 离子凝胶法可以得到粒径约430 nm的均匀分散的壳聚糖纳米微胶囊, 经冷冻干燥后粒径变为300 nm左右; 微胶囊包封率最高可达79.74%, 模型药物的持续释放时间可达7 d以上.     

三聚磷酸二氢铝/载硫硅藻土催化合成阿司匹林

以三聚磷酸二氢铝/载硫硅藻土为催化剂,水杨酸(1)和乙酰酐(2)经酯化反应合成了阿司匹林(3),其结构经IR确证。采用单因素实验考察了反应条件对3收率的影响,实验结果表明:各因素影响顺序为:反应温度原料配比[r=n(2)∶n(1)]反应时间催化剂用量。在最佳反应条件[1 50 mmol,催化剂用量5%,r=n(2)∶n(1)=3.14,于81℃反应40 min]下,收率88.6%。催化剂经五次重复使用后收率仍达83.3%。     

Lithium amidohydridoaluminates

The amidohydridometalates [Li(THF)4][HAl(NPh2)3] (1), [Li(DME)3][HAl(N(CH2Ph)2)3] (2), and [((THF)3Li)-(H2Al(NcHex2)2)].0.5toluene (3.0.5toluene; cHex = C6H11) have been prepared by reaction of the corresponding amines with LiAlH4 in THF. For 2 recrystallization from DME is required to obtain crystals, suitable for X-ray diffraction. The new compounds have been characterized by elemental analyses, IR, NMR, and MS techniques, and X-ray structure analyses. According to this the anions of 1, 2, and 3x0.5toluene possess distorted tetrahedral coordination spheres. In 3x0.5toluene a Li...H contact of 184(4) pm was detected to complete the tetrahedral coordination of the Li+ center.     

Carbon-Based Materials as Lithium Hosts for Lithium Batteries

Lithium (Li) metal has attracted significant attention in areas that range from basic research to various commercial applications due to its high theoretical specific capacity (3860 mA h g⁻¹) and low electrochemical potential (−3.04 vs. standard hydrogen electrode). However, dendrites often form on the surfaces of Li metal anodes during cycling and thus lead to battery failure and, in some cases, raise safety concerns. To overcome this problem, a variety of approaches that vary the electrolyte, membrane, and/or anode have been proposed. Among these efforts, the use of three-dimensional frameworks as Li hosts, which can homogenize and minimize the current density at the anode surface, is an effective approach to suppress the formation of Li dendrites. Herein, we describe the development of using carbon-based materials as Li hosts. While these materials can be fabricated into a variety of porous structures, they have a number of intrinsic advantages including low costs, high specific surface areas, high electrical conductivities, and wide electrochemical stabilities. After briefly summarizing the formation mechanisms of Li dendrites, various methods for controlling structural and surface chemistry will be described for different types of carbon-based materials from the viewpoint of improving their performance as Li hosts. Finally, we provide perspective on the future development of Li host materials needed to meet the requirements for their use in flexible and wearable devices and other contemporary energy storage techniques.     

Magnetohydrodynamic Interface-Rearranged Lithium Ions Distribution for Uniform Lithium Deposition and Stable Lithium Metal Anode

Uneven lithium (Li) electrodeposition hinders the wide application of high-energy-density Li metal batteries (LMBs). Current efforts mainly focus on the side-reaction suppression between Li and electrolyte, neglecting the determinant factor of mass transport in affecting Li deposition. Herein, guided Li⁺ mass transport under the action of a local electric field near magnetic nanoparticles or structures at the Li metal interface, known as the magnetohydrodynamic (MHD) effect, are proposed to promote uniform Li deposition. The modified Li⁺ trajectories are revealed by COMSOL Multiphysics simulations, and verified by the compact and disc-like Li depositions on a model Fe₃O₄ substrate. Furthermore, a patterned mesh with the magnetic Fe−Cr₂O₃ core-shell skeleton is used as a facile and efficient protective structure for Li metal anodes, enabling Li metal batteries to achieve a Coulombic efficiency of 99.5 % over 300 cycles at a high cathode loading of 5.0 mAh cm⁻². The Li protection strategy based on the MHD interface design might open a new opportunity to develop high-energy-density LMBs.     

Lithium Nitrate Regulated Sulfone Electrolytes for Lithium Metal Batteries

The electrolytes in lithium metal batteries have to be compatible with both lithium metal anodes and high voltage cathodes, and can be regulated by manipulating the solvation structure. Herein, to enhance the electrolyte stability, lithium nitrate (LiNO₃) and 1,1,2,2-tetrafuoroethyl-2′,2′,2′-trifuoroethyl(HFE) are introduced into the high-concentration sulfolane electrolyte to suppress Li dendrite growth and achieve a high Coulombic efficiency of >99 % for both the Li anode and LiNi_0.8Mn_0.1Co_0.1O₂ (NMC811) cathodes. Molecular dynamics simulations show that NO₃⁻ participates in the solvation sheath of lithium ions enabling more bis(trifluoromethanesulfonyl)imide anion (TFSI⁻) to coordinate with Li⁺ ions. Therefore, a robust LiN_xO_y−LiF-rich solid electrolyte interface (SEI) is formed on the Li surface, suppressing Li dendrite growth. The LiNO₃-containing sulfolane electrolyte can also support the highly aggressive LiNi_0.8Mn_0.1Co_0.1O₂ (NMC811) cathode, delivering a discharge capacity of 190.4 mAh g⁻¹ at 0.5 C for 200 cycles with a capacity retention rate of 99.5 %.     

Solubility of Lithium Nitrate in Solutions of Lithium Halides

Summary. Solubility isotherms in LiNO₃ – LiX – H₂O (X = Cl, Br, I) systems at 298.15 K were measured for the first time with special regard to the retrograde solubility of lithium nitrate trihydrate. The compositions of solutions used as media in absorption refrigerators and heat pumps were compared with the results and subsequently discussed.     

铌酸锂、钽酸锂晶体的结构特征

从铌酸锂和钽酸锂晶体的结晶学数据出发,分析其结构特征和组成化学键的结合情况.对于这两个晶体的结晶学格位占有情况和阳离子的位移进行了理论上的分析.作者首次明确地给出了铌酸锂和钽酸锂晶体中与晶体组成有关的阳离子位移趋势.     

Preparation and Use of Lithium Tritide and Lithium Trimethoxyborotritide

Two new tritide reducing agents, Li³H and Li(CH₃O)₃B³H, have been prepared at the carrier-free level and used to reduce 2-naphthaldehyde to tritiated β-naphthalene methanol, to produce C³H₃OR, and to synthesize a methyl-tritiated secondary amine.