锂二次电池中的原位聚合电解质

聚合物电解质主要分为凝胶聚合物电解质和固态聚合物电解质两种类型,均能够提升锂二次电池的性能.其中,凝胶聚合物电解质是利用增塑剂实现聚合物基质的凝胶化,将有机液态电解液固定在三维网络结构中,因此同时具备液态的离子扩散速率和固态材料的机械性能;而固态聚合物电解质是一种完全没有液态电解质的体系,利用聚合物基体的极性实现锂盐的...     

PAN-LATP复合固态电解质的制备与性能表征

与传统的液态电解质相比,固态聚合物电解质可以显著提高锂二次电池的安全性和能量密度,但其室温锂离子传导率低、机械性能比较差,这些缺点限制了固态聚合物电解质在锂二次电池中的应用.为了解决上述问题,本文采用溶液浇铸法在聚丙烯腈(PAN)固态聚合物电解质中引入无机固态电解质Li_(1.3)Al_(0.3)Ti_(1.7)(PO_4)_3(LATP)制备了PAN-LATP复合固态电解质(CSE).该复合固态电解质不仅具有较高的锂离子电导率,还拓宽了电化学稳定窗口.当LATP含量为15%时CSE的锂离子传导率最高,室温下为2.14×10~(-5)S/cm,333 K时为3.03×10~(-4)S/cm.与此同时,固态聚合物电解质的机械强度也得到了很好的改善.结果表明该性能优良的固态电解质有望用于锂离子电池和其他电化学储能系统.     

现场热引发聚丙烯酸酯类电解质的性能及应用

应用热引发现场聚合方法制备聚丙烯酸酯类电解质,并考察其电化学性能.实验表明:该聚合物电解质具有 4. 5V的电化学稳定窗口,较高的室温电导率及良好的低温性能.当前驱体电解液中液态电解质含量为 85%时,其室温电导率为 3. 2×10-3S·cm-1, -30℃下的电导率达到 5. 6×10-4 S·cm-1.采用现场聚合技术制备的聚合物电池,其电化学性能与液态锂离子电池基本一致,首次充放电效率为 92. 1%, 1. 0C率放电容量为 0. 2C率的 95%, -20℃下的放电容量为室温容量的 72%,以 0. 5C率循环 300周后,仍保持初始容量的 85%以上.     

2,2'-双氨基苯氧基二硫化物及其聚合物的合成研究

在不同的锂或锂离子二次电池正极材料中 ,新型的聚有机二硫化物有可能成为最有应用前景的电池正极材料之一 [1] ,Visco等 [2 ]首次提出利用二硫化物中双硫键的断裂与再接 (即电聚合与电解聚 )化学性能应用于锂二次电池的充放电 .目前 ,对有代表性的有机二硫化物 2 ,5 -二巯基 -1 ,3 ,4-噻二唑(DMc T)进行了大量的研究[3～ 5] ,最近又提出通过合成新的聚有机二硫化物来提高其电化学性能[6 ,7] .为了得到一种新型高电化学活性和高导电性的锂或锂离子二次电池正极材料 ,本文通过化学方法合成2 ,2 -双氨基苯氧基二硫化物 (DAPD)单体 ,并通…     

锂-空气二次电池关键材料与器件的设计与制备

锂-空气二次电池因拥有超高的理论能量密度及巨大的应用潜力, 有望替代锂离子电池成为下一代高性能化学 电源. 高效、稳定电极的制备以及新型锂-空气电池器件的开发是提升电池电化学性能, 促进其应用的关键. 针对以上 问题, 本文对空气正极材料的开发与设计、锂负极的修饰保护以及锂-空气二次电池器件进行了简要介绍, 并对该领域 进行总结展望     

锂-硫二次电池界面反应的特殊性与对策分析

锂-硫电池是在现有锂离子电池基础上最可能实现储能密度大幅提升的实用二次电池体系. 然而,这一电池体系的电化学利用率与循环稳定性仍然难以满足应用要求. 造成锂-硫电池性能不稳定的原因在于硫正极和锂负极的材料结构和反应环境始终处于变化之中,如在充放电过程中,硫-碳反应界面的电化学阻塞、中间产物的溶解流失、正负极之间的穿梭效应等副反应导致正极与负极均难形成稳定的电化学反应界面。针对这些特殊问题,本文简要分析了影响能量利用率和循环稳定性的化学与电化学机制,并提出了构建稳定锂负极与高效硫正极的若干可行性技术.     

二甲基亚砜在锂二次电池中的应用

采用二甲基亚砜(DMSO)作为锂二次电池的电解液, 研究了锂在DMSO中的沉积形貌和循环效率. 比较了六氟磷酸锂(LiPF₆)在DMSO、 碳酸丙烯酯(PC)和1,3-二氧环戊烷(DOL)3种溶剂中的沉积形貌和循环效率, 并研究了LiPF₆、 四氟硼酸锂(LiBF₄)、 高氯酸锂(LiClO₄)和二(三氟甲基磺酰)亚胺锂(LiTFSI)4种锂盐在DMSO中的沉积形貌和循环效率. 结果表明, 锂在DMSO中沉积得到的表面光滑平整且致密均匀, 循环效率在前10周要高于在PC中的, 溶剂DMSO有望用于金属锂二次电池中.     

一种新型凝胶态聚合物电解质的制备和性能

采用一种新型胶联剂新戊二醇二丙烯酸酯(noepentyl glycol diacrylate, NPGDA)和聚偏氟乙烯-六氟丙烯(poly(vinylidene fluoride-co-hexafluoropropylene), PVDF-HFP), 液态电解液组成电解质混合溶液, 然后加入引发剂并加热引发聚合反应制备了一种具有互穿聚合物网络结构的凝胶态聚合物电解质, 可以用于制备聚合物锂离子二次电池. 考察了不同PVDF-HFP/NPGDA质量比对凝胶态聚合物电解质性能的影响. 结果表明, PVDF-HFP/NPGDA质量比可以影响凝胶态聚合物电解质的结构形貌、电化学特性以及聚合物锂离子二次电池的性能. 研究发现, 当m(PVDF-HFP)/m(NPGDA)＝1:1时制备的凝胶态聚合物电解质具有较高的离子电导率和电化学稳定窗口, 室温下分别为6.99×10^-3 S•cm^-1和4.8 V(vs Li⁺/Li), 以其为电解质制备的聚合物锂离子二次电池具有较好的电化学性能.     

聚丙烯腈在锂金属电池电解质中的应用

随着便携式电子设备、电动汽车和智能电网等快速发展，人们对高能量密度锂金属电池的关注日益增多。锂金属表面不均匀的剥落或沉积会导致锂枝晶生长，锂枝晶容易刺穿隔膜，存在引发电池短路的风险，而且高反应活性的锂金属会与电解液不断反应被消耗，生成不稳定的固体电解质界面（SEI）膜，造成不可逆的容量损失，因此兼顾高能量密度与高安全性是锂金属电池发展应用中亟需解决的关键科学问题。具有强吸电子基团（C≡N）的聚丙烯腈（PAN）聚合物与碳酸酯溶剂中C=O的相互作用能形成更稳定的SEI膜，PAN作为锂负极涂层还能抑制锂枝晶的生长；另外，PAN具有较低的最低未占据分子轨道、较高的电化学稳定性和较宽的电化学窗口，能作为锂金属电池的聚合物电解质，并匹配高电压正极，兼具高能量密度和高安全性，故PAN聚合物在锂金属电池的电解质中有着很大的应用潜力。本文从电解质的不同状态（液态、凝胶、固态）介绍了PAN聚合物在液态电解质中作为隔膜、锂负极保护层以及在凝胶电解质、固态电解质的最新研究成果，并对PAN聚合物在锂金属电池电解质中的发展趋势进行展望。     

高陶瓷含量复合固态电解质

全固态锂二次电池兼具高能量密度和高安全性特点.高陶瓷含量的陶瓷-聚合物复合固态电解质综合了聚合物电解质的柔韧性和陶瓷电解质的高机械强度与高锂离子迁移数等优点,有望优先其他形式固态电解质应用于全固态锂二次电池.本文在简要介绍固态复合电解质后,重点从复合电解质膜的性能特点与制备方法、陶瓷-聚合物界面相互作用以及由此导致的新...     

In situ fabrication of lithium polymer battery basing on a novel electro-polymerization technique

Electro-polymerization technology is proposed for the in situ fabrication of polymer lithium secondary battery and exciting results have been obtained. The polymerization starts from a common used electrolyte of 1 M LiTFSI in DOL/DME (2:1 by weight) with no initiator addition through a routine charge–discharge treatment under some appointed current rate. It is found that once an appropriate current is applied in the charging–discharging of Li/1 M LiTFSI in DOL + DME/LiCoO₂ cell, the original liquid electrolyte polymerizes readily during the first several cycles in an irreversible mode, and thus the desired polymer electrolyte obtained. SEM observation indicates that unlike previous report, the designed electro-polymerization does not result in destructive local break and then turnoff of the circuit, just the reverse, it helps to the formation of a smooth polymer layer, which can effectively protect the lithium substrate from corrosion and dendrite growth. Detailed examination shows that the in situ electro-polymerization does not disturb the electrochemical behavior of the cell, the cycleabilty, internal resistance are all comparable to that of a normal Li/LiCoO₂ liquid secondary battery.     

锂金属电池用三维半互穿网络聚合物电解质的制备

锂金属电池作为下一代高比能量电池技术受到人们越来越广泛的关注。然而由锂枝晶生长引发的安全问题是锂金属电池商业化面临的最大挑战之一。具有高锂离子迁移数和离子电导率的聚合物电解质是抑制锂枝晶生长的重要策略之一。本文将季戊四醇四丙烯酸酯和自由基引发剂AIBN添加至商业化电解液中,采用具有单离子传导功能的多孔聚合物电解质为锂金属电池的电解质隔膜,通过在电池内部发生热诱导原位聚合制备三维半互穿网络单离子传导聚合物电解质,达到提高电解质隔膜离子电导率和机械拉伸性能,以及有效抑制锂枝晶生长的目的。通过该策略的实施,成功获得了室温离子电导率0.53 mS·cm^-1和锂离子迁移数0.65的良好结果。应用于锂金属电池,证明该电解质能够有效抑制锂枝晶的生长和倍率性能的提高,为锂金属电池的开发提供了良好的解决路径。     

金属锂二次电池锂负极改性

本文综述了金属锂二次电池中提高锂负极性能的研究进展。分别介绍了以下改性方法:对金属锂表面进行预处理,使其表面预先形成性能良好的固体电解质界面膜,或直接在其表面制备保护膜;在电解液中加入添加剂对锂电极进行表面改性;采用新型有机溶剂、离子液体、聚合物电解质、玻璃态固体电解质、塑晶固体电解质等电解质体系提高界面相容性;改进金属锂电极的制备工艺,如制备金属锂粉末多孔电极和电沉积锂电极、制备全固态薄膜锂电池以及利用物理方法处理锂电极。并在此基础上对今后的发展趋势进行了展望。     

Poly[N‐(10‐oxo‐2‐vinylanthracen‐9(10H)‐ylidene)cyanamide] as a novel cathode material for li‐organic batteries

Redox‐active polymers draw significant attention as active material in secondary batteries during the last decade. A new anthraquinone‐based redox‐active monomer was designed, which electrochemical behavior was tailored by mono‐modification of one keto group. The monomer exhibits two one‐electron redox reactions and has a low molar mass, resulting in a high theoretical capacity of 207 mAh/g. The polymerization of the monomer was optimized by variation of solvent and initiator. Moreover, the electrochemical behavior was studied using cyclic voltammetry and the polymer was used as active material in a composite electrode in lithium organic batteries. The polymer reveals a cell potential of 2.3 V and a promising capacity of 137 mAh/g. During the first 100 cycles, the capacity drops to 85% of the initial value. The influence of the charging speed on the charging/discharging properties of the batteries was further investigated. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2517–2523     

用于锂离子电池聚合物电解质的组成、结构和性能

聚合物电解质是全固态锂离子电池的重要组成部分, 其电导率对电池的性能有很重要的影响.本文综述了聚合物电解质的组成、结构和性能对锂 离子电池导电率影响的最新研究进展,特别是介绍了聚合物-碱金属盐复合电解质和聚离子体电解质两个体系的研究进展.     

金属锂二次电池研究进展

本文综述了近年来金属锂二次电池的研究进展,主要包括金属锂负极的表面改性、SEI膜的形成和调制、电解质体系的改进及研发,以及电池制备工艺等,并在综述各方面进展的基础上对金属锂二次电池未来的研究方向进行了展望。     

Ultraviolet-Cured Semi-Interpenetrating Network Polymer Electrolytes for High-Performance Quasi-Solid-State Lithium Metal Batteries

Solid polymer electrolytes with relatively low ionic conductivity at room temperature and poor mechanical strength greatly restrict their practical applications. Herein, we design semi-interpenetrating network polymer (SNP) electrolyte composed of an ultraviolet-crosslinked polymer network (ethoxylated trimethylolpropane triacrylate), linear polymer chains (polyvinylidene fluoride-co-hexafluoropropylene) and lithium salt solution to satisfy the demand of high ionic conductivity, good mechanical flexibility, and electrochemical stability for lithium metal batteries. The semi-interpenetrating network has a pivotal effect in improving chain relaxation, facilitating the local segmental motion of polymer chains and reducing the polymer crystallinity. Thanks to these advantages, the SNP electrolyte shows a high ionic conductivity (1.12 mS cm⁻¹ at 30 °C), wide electrochemical stability window (4.6 V vs. Li⁺/Li), good bendability and shape versatility. The promoted ion transport combined with suppressed impedance growth during cycling contribute to good cell performance. The assembled quasi-solid-state lithium metal batteries (LiFePO₄/SNP/Li) exhibit good cycling stability and rate capability at room temperature.     

锂电池用嵌段共聚物电解质的研究进展

离子导体嵌段共聚物电解质作为一种固态锂电池导离子材料引起了人们的广泛关注。嵌段共聚物的自组装行为为设计微观尺寸有序结构提供了一种可能。这种有序纳米结构既保证聚合物电解质良好的机械性能,同时又拥有与其它聚合物电解质相当的离子电导率,为进一步组装高性能、易加工的锂电池器件提供了一种可能。本文综述了聚氧化乙烯型嵌段共聚物和单离子型嵌段共聚物,并总结了近期嵌段共聚物电解质的形貌影响离子电导率的实验研究结果,最后评述了嵌段共聚物电解质面临的挑战,并对未来研究进行了展望。     

Li[B(OCH2CF3)4]: Synthesis,Characterization and Electrochemical Application as a Conducting Salt for LiSB Batteries

A new Li salt with views to success in electrolytes is synthesized in excellent yields from lithium borohydride with excess 2,2,2‐trifluorethanol (HOTfe) in toluene and at least two equivalents of 1,2‐dimethoxyethane (DME). The salt Li[B(OTfe)₄] is obtained in multigram scale without impurities, as long as DME is present during the reaction. It is characterized by heteronuclear magnetic resonance and vibrational spectroscopy (IR and Raman), has high thermal stability (T_{decomposition}>271 °C, DSC) and shows long‐term stability in water. The concentration‐dependent electrical conductivity of Li[B(OTfe)₄] is measured in water, acetone, EC/DMC, EC/DMC/DME, ethyl acetate and THF at RT In DME (0.8 mol L ^?1) it is 3.9 mS cm^?1, which is satisfactory for the use in lithium‐sulfur batteries (LiSB). Cyclic voltammetry confirms the electrochemical stability of Li[B(OTfe)₄] in a potential range of 0 to 4.8 V vs. Li/Li⁺. The performance of Li[B(OTfe)₄] as conducting salt in a 0.2 mol L ^?1 solution in 1:1 wt % DME/DOL is investigated in LiSB test cells. After the 40th cycle, 86 % of the capacity remains, with a coulombic efficiency of around 97 % for each cycle. This indicates a considerable performance improvement for LiSB, if compared to the standard Li[NTf₂]/DOL/DME electrolyte system.     

Fabrication and evaluation of a polymer Li-ion battery with microporous gel electrolyte

This paper introduces an easy method for the fabrication of polymer Li-ion batteries with microporous gel electrolyte (MGE). The MGE is a multiphase electrolyte, which is composed of liquid electrolyte, gel electrolyte, and polymer matrix. The MGE not only has high ionic conductivity and good adhesion to the electrodes at low temperatures, but also retains good mechanical strength at elevated temperatures. Therefore, the MGE batteries are able to operate over a wide temperature range. During battery fabrication, the MGE is formed in situ by introducing liquid electrolyte into a swellable microporous polymer membrane and then heating or cycling the battery. In this work, the chemical compatibility of MGE with metal lithium during 60 °C storage and with LiMn₂O₄ cathode during cycling was studied. In addition, graphite/MGE/LiMn₂O₄ Li-ion batteries were made and evaluated.