锂离子电池新型电解质锂盐的研究进展

重点介绍了锂离子电池电解液中有机锂盐电化学性质及研究现状。所述新型电解质锂盐主要包括:含硼类锂盐、亚胺类锂盐及其他新盐。最后对新型电解质锂盐未来发展的趋势进行论述。     

新型锂盐二氟草酸硼酸锂的研究进展

介绍了一种新型锂盐二氟草酸硼酸锂(LiODFB)的基本性质和制备进展,以及在锂离子电池应用中的基本特性.使用LiODFB电解液的电池电化学性能优良、对电极材料相容性较好、与其他锂盐混合使用性能良好,有望成为动力电池用电解质锂盐。     

电解液化学保护锂金属电池负极的研究进展

锂金属电池被认为是最具潜力的高能量密度储能器件之一,但是锂金属电池负极低库仑效率及不可控的枝晶生长等问题阻碍了其商业化进程.在锂金属电池中,电解液会直接参与固态电解质界面膜(SEI)的形成,对锂金属负极的库仑效率、枝晶生长等产生重要影响.传统LiPF6基酯类电解液中,锂金属库仑效率低,且锂枝晶现象严重.近年来通过电解液添加剂、溶剂、锂盐以及锂盐浓度等途径调控电解液化学,在锂金属负极保护上取得了显著效果.例如,采用与锂金属负极兼容性更佳的醚类溶剂,可以降低电解液与锂金属的反应性;采用多种添加剂与新型锂盐复配可以有效抑制锂枝晶的形成;采用高浓度锂盐电解液,可以形成稳定SEI膜等.本文综述了锂枝晶的生长原理以及通过溶剂、锂盐、添加剂和高浓度电解液等策略调控电解液化学保护锂金属电池负极的研究现状,总结了各种途径的优势及局限性.并对锂金属电池电解液的发展提出了新的见解,以激发新的策略面对锂金属电池后续的挑战.     

PVDF为基的聚合物固态电解质离子导电膜的结构与性能研究

制备了聚偏氟乙烯 (PVDF) 锂盐 增塑剂聚合物固态电解质 ,并测定了该类电解质的电导率 ,结果表明 :以聚偏氟乙烯为基的凝胶电解质的室温电导率超过了 10 -3 S·cm-1,电导率与温度的关系服从VTF方程。并对该电解质进行了红外、扫描电镜、X衍射分析 ,发现了一个新相 ,并证实了在聚偏氟乙烯、锂盐、增塑剂三者之间共存的相互作用规律。     

锂离子电池电解质用含硼锂盐研究进展

电解质材料是锂离子电池的关键材料之一。LiBF4、双草酸硼酸锂(LiBOB)及草酸二氟硼酸锂(LiODFB)是极具应用前景的3种含硼锂盐。介绍了3种锂盐各自的优缺点及研究近况,重点综述了它们的离子传导特性及与电极材料的相容性能。     

一种基于Al2O3纳米纤维骨架的锂硫电池用凝胶聚合物电解质(英文)

锂硫电池作为一种极具前景的二次电池系统受到了广泛关注.然而,传统液态电解质中多硫化锂的穿梭效应阻碍了其发展.在本工作中,我们制备了用于锂硫电池的功能性凝胶电解质.该电解质由聚偏氟乙烯-六氟丙烯(PVDF-HFP)和连续γ-Al₂O₃三维骨架组成. PVDF-HFP提供锂离子传输路径,使电解质具有良好的柔性; γ-Al₂O₃为路易斯酸,可通过与多硫化锂之间的路易斯酸碱相互作用抑制穿梭效应.而且, γ-Al₂O₃与路易斯碱TFSI-有相互作用,可促进锂盐解离,提高锂离子迁移数.此外,部分γ-Al₂O₃可以与LiF反应形成锂离子导体LiAlO₂和Li₃AlF₆来提高离子电导率.使用该凝胶电解质的锂硫电池在正极容量保持和负极形貌方面展现出良好的稳定性.该项研究为制备高能量锂硫电池的多功能凝胶电解质提供了一种有前景的策略.     

增塑盐改性准固态电解质染料敏化纳米晶太阳能电池

实验使用一种增塑性试剂—双（三氟甲基磺酰）亚胺锂改性PEO-PVDF基聚合物电解质设计并制备了一系列不同浓度双（三氟甲基磺酰）亚胺锂[LiN（SO2CF3）2,LiTFSI]改性的PEO基聚合物电解质。在聚合物电解质中LiTFSI起着增塑剂的作用,经其改性后,聚合物电解质的玻璃化转变温度降低,有利于高分子链段运动和离子传输,进而提高离子的电导率。最终对经增塑盐改性的电解质的特性及其所组装的染料敏化纳米晶太阳电池的光电转换性能进行了研究。     

聚合物锂盐在锂离子电池电解质中的应用EI北大核心CSCD

锂盐是获得安全性能良好的锂离子二次电池的重要因素。聚合物锂盐具有高电导率、宽电化学窗口、良好热稳定性和电化学稳定性,以及在全固态锂离子电池中的应用引起了国内外研究者的关注。文中分析了聚合物锂盐的结构与电池性能之间的关系,包括结构对材料的热稳定性、力学性能、锂离子迁移数、离子电导率和电化学窗口等的影响。总结了聚合物锂盐的合成方法,综述了均聚物型、共聚物型和离子液体型等具有代表性的聚合物锂盐在锂离子电池电解质中的应用研究进展,并对未来新型锂盐的研究方法及发展方向进行了展望。     

聚合物锂盐在锂离子电池电解质中的应用

锂盐是获得安全性能良好的锂离子二次电池的重要因素。聚合物锂盐具有高电导率、宽电化学窗口、良好热稳定性和电化学稳定性,以及在全固态锂离子电池中的应用引起了国内外研究者的关注。文中分析了聚合物锂盐的结构与电池性能之间的关系,包括结构对材料的热稳定性、力学性能、锂离子迁移数、离子电导率和电化学窗口等的影响。总结了聚合物锂盐的合成方法,综述了均聚物型、共聚物型和离子液体型等具有代表性的聚合物锂盐在锂离子电池电解质中的应用研究进展,并对未来新型锂盐的研究方法及发展方向进行了展望。     

高安全性锂离子电池电解质研究进展

电解质是锂离子电池的重要组成部分,其电化学性能和热稳定性是影响电池安全性能的重要因素.简要介绍了商用锂离子电池电解质的性质以及由其引起的安全问题,从替代电解质材料和电解质添加剂两个方面综述了高安全性锂离子电池电解质的研究现状,着重阐述了离子液体、聚合物电解质、新型锂盐、成膜添加剂和阻燃添加剂等对锂离子电池安全性能提高的最新进展,展望了锂离子电解液的发展方向.     

Influence of the electrolysis conditions and composition of electrolytes in the M2WO4-M2W2O7-UO2WO4 system (M = Li, Na, K, Cs) on the oxygen coefficient of uranium oxide

The oxygen coefficient (O/U atomic ratio) of the cathodic product prepared by potentiostatic electrolysis of tungstate melts was studied in relation to the electrolyte composition, deposition potential, temperature of electrolysis, and cation of the solvent salt. With increasing temperature, the oxygen coefficient of the cathodic product increases. With shifting the deposition potential toward more negative potentials, with increasing concentration of W₂O ₇ ^2? anions, and with decreasing concentration of UO₂WO₄ in the tungstate electrolytes, uranium oxides with smaller oxygen coefficients are formed. The oxygen coefficient decreases with increasing radius of the salt cation, other conditions being equal. The abnormal behavior of melts based on Li₂WO₄ is probably due to lower activity of O^2? anions capable to form strong Li₃O⁺ complexes with lithium cations in the melt. The experimental results can be accounted for using the model of the ionic composition of uranyl-containing tungstate melts based on the concepts of complexation and stepwise solvolysis of uranyl ions.     

Management of composition cathodic products in the electrolysis of molybdenum‐, tungsten‐ and carbon‐ bearing halogenide‐oxide and oxide melts

It is shown that the cathode products of electrolysis of melts based on a eutectic mixture of sodium chloride and lithium fluoride as well as melts based on sodium tungstate in which dissolved oxides of molybdenum (VI) or tungsten (VI), molybdate, tungstate and lithium or sodium carbonates are molybdenum, tungsten, their bronzes and carbides, carbon. It is established that the phase composition of electrolysis products is determined by the concentration of carbonate in the melt. Particular conditions of plating coating of molybdenum and tungsten carbides on carbon, nickel and copper materials are determined. Molybdenum carbide coatings of electrolyte Na₂WO₄–Li₂MoO₄–Li₂CO₃ are deposited at equality (within 2.5 mol%) of concentrations molybdate and lithium carbonate. However, their concentrations should not exceed 10 mol%. At lower concentrations of molybdate in the precipitate are detected carbon, molybdenum, molybdenum carbide, and at high concentrations – molybdenum oxides. At lower concentrations of carbonate in the sediment dominates molybdenum and at large concentrations mainly free carbon is released. More affordable industrial reagent‐source of molybdenum is its oxide.     

The Technological Improvements of Aluminum Alloy Coloring by Electrolysis

The technological process of coloring golden-tawny on aluminum alloy by electrolysis was improved in this paper. The optimum composition of electrolyte was found, the conditions of deposition and anodic oxidation by electrolysis were studied. The oxidative membrane on aluminum alloy was satisfying, the colored aluminum alloy by electrolysis is uniformity,bright and beautiful, and the coloring by electrolysis is convenient and no pollution.     

尖晶石型LiMn2O4容量衰减因素及改性研究进展

本文论述了锂离子蓄电池正极材料尖晶石型LiMn2O4的结构、性质及容量衰减的原因.从体相掺杂、表面修饰、电解液优化、添加剂的使用及材料比表面积几个方面,对改善LiMn2O4循环及高温性能的技术或方法进行了综述.     

In Vitro Iontophoretic Release of Lithium Chloride and Lidocaine Hydrochloride from Polymer Electrolytes

Ionically conducting polymers, frequently known as polymer electrolytes, are potential candidates as hosts for drugs to be delivered iontophoretically. The iontophoretic delivery of lithium or lidocaine from polymer electrolyte films through a cellophane membrane was examined using different delivery current regimes. Thin, mechanically strong, polymer electrolyte films were fabricated from poly(ethylene oxide) (PEO) with lithium chloride or lidocaine hydrochloride. Experiments showed that iontophoretic transport of both lithium chloride and lidocaine hydrochloride might be achieved from these PEO-based films. Cation transport number determinations give values for PEO-based films of about 0.4 for lithium chloride systems and 0.12 for lidocaine hydrochloride systems. The mechanism of transport from these PEO-based polymer electrolyte films allows the delivery of ionic salts such as lithium chloride and lidocaine hydrochloride to be controlled solely by current, thus providing a system that can deliver precise amounts of drug.     

用阴极电解法沉积铝合金铈转化膜

在铈盐溶液中阴电极解的方法沉积铝合金铈转化膜,用电化测试,腐蚀实验,ＳＥＭ和ＥＤＡＸ等分析手段研究了转化膜的性能,结果表明,钪转化膜的形貌垢形貌组成和耐蚀与铝合金表面状态和阴极是否发生析氢反应关系密切,要想获得性能良好的转化膜必须抑制氢气在阴极上析出。     

In vitro iontophoretic release of lithium chloride and lidocaine hydrochloride from polymer electrolytes

Ionically conducting polymers, frequently known as polymer electrolytes, are potential candidates as hosts for drugs to be delivered iontophoretically. The iontophoretic delivery of lithium or lidocaine from polymer electrolyte films through a cellophane membrane was examined using different delivery current regimes. Thin, mechanically strong, polymer electrolyte films were fabricated from poly(ethylene oxide) (PEO) with lithium chloride or lidocaine hydrochloride. Experiments showed that iontophoretic transport of both lithium chloride and lidocaine hydrochloride might be achieved from these PEO-based films. Cation transport number determinations give values for PEO-based films of about 0.4 for lithium chloride systems and 0.12 for lidocaine hydrochloride systems. The mechanism of transport from these PEO-based polymer electrolyte films allows the delivery of ionic salts such as lithium chloride and lidocaine hydrochloride to be controlled solely by current, thus providing a system that can deliver precise amounts of drug.     

Influence of Finely Dispersed Carbon Nanotubes on the Performance Characteristics of Polymer Electrolytes for Lithium Batteries

Electrospun membranes of poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP)/multiwall carbon nanotube (MWCNT) composite are prepared and loaded with lithium salts from electrolyte solution. Field emission transmission electron microscopy provides evidence for the uniform distribution of MWCNTs into the matrix of PVdF-HFP. The interconnected morphology as evident from field emission scanning electron micrograph forms the path for the lithium ion conduction. Results from electrochemical impedance spectroscopy inform that the presence of MWCNTs in PVdF-HFP matrix improves interfacial stability between lithium electrode and membrane and augment conduction path in the polymer electrolyte membrane. Further results from impedance measurement reveal the contribution of MWCNTs toward conductivity. A prototype cell is fabricated with PVdF-HFP/MWCNT as polymer electrolyte. The electrospun PVdF-HFP electrolyte membrane with 2% MWCNTs content shows an ionic conductivity of about 5.85 mSmiddotcm^-1 at 25 degC. Also, PVdF-HFP/MWCNT electrolyte membrane exhibits good electrochemical and interfacial stability and can be potentially suitable as electrolyte in lithium ion secondary battery     

基于锂盐的新型锂电池电解质研究进展

随着新能源汽车、可携带式电源和储能等领域的快速发展, 人们对锂电池性能提出了更高的要求, 高性能锂离子电池的重要性日益突出。电解质是锂离子电池的重要组成部分, 对于电池的输出电压、倍率性能、适用温度范围、循环性能和安全性能等有着重要的影响。而锂盐作为液体电解质(电解液)的关键组分, 是决定电解液性能的重要因素。电解液中不同种类的锂盐及其在溶液中不同的溶剂化状态, 会对电极/电解液界面的成膜性能和锂离子的迁移行为等产生重要影响, 进而显著影响电解液的电化学性能。本文介绍了近年来新型电解质锂盐的性质特点和在不同种类电池中的应用。同时, 单一的锂盐不能完全满足锂电池对电解液的要求, 因而人们尝试采用复合锂盐使功能更完善, 催生了多盐体系电解液。多盐体系电解液在拓宽电池工作温度、抑制金属离子溶出和提高倍率性能等方面表现出明显优势。同时, 借助于浓度的提升改变锂离子的溶剂化结构, 研究人员提出了高浓度电解液。高浓度电解液在防止石墨剥离、拓宽电解液电化学窗口、抑制铝箔腐蚀和提高金属锂沉积/溶出性能等方面具有明显优势。并且, 本文重点讨论了这两种电解液对电池性能提升的机理。最后, 对锂盐基电解液尤其是这两类新型电解液的发展趋势和应用前景进行了展望。     

Electrolytes for Tungsten Refining

Chloride–fluoride and phosphate–fluoride salts of alkali metals with additions of sodium tungstate and tungstic anhydride are studied as electrolyte systems for tungsten refining. The results demonstrate that the melts of these systems are suitable for electrolytic processes. Coarse crystalline tungsten powder with reduced concentrations of some impurities is prepared.