固态锂电池中正极/电解质界面的密度泛函计算研究

锂离子电池的广泛应用对储能器件的能量密度、安全性和充放电速度提出了新的要求. 全固态锂电池与传统锂离子电池相比具有更少的副反应和更高的安全性,已成为下一代储能器件的首选. 构建匹配的电极/电解质界面是在全固态锂电池中获得优异综合性能的关键. 本文采用第一性原理计算研究了固态电池中电解质表面及正极/电解质界面的局域结构和锂离子输运性质. 选取β-Li₃PS₄ (010)/LiCoO₂ (104)和 Li₄GeS₄ (010)/LiCoO₂ (104)体系计算了界面处的成键情况及锂离子的迁移势垒. 部分脱锂态的正极/电解质界面上由于Co-S成键的加强削弱了P/Ge-S键的强度,降低了对Li⁺的束缚,从而导致了更低的锂离子迁移势垒. 理解界面局域结构及其对Li+输运性质的影响将有助于我们在固态电池中构建性能优异的电极/电解质界面.     

New approaches to developing lithium polymer batteries

The electrochemical and physical-chemical properties of two families of lithium ion conducting membranes, i.e., the blends between high molecular weight poly(ethylene oxide) with a lithium salt commonly named "polymer electrolytes" and the gels of liquid solutions in a polymer matrix commonly named "gel electrolytes," are repoted and discussed. Particular attention is devoted to the newly developed approach of dispersing ceramic powders at the nanoscale particle dimension into the two types of membranes. This leads "nanocomposite" membranes having unique features, such as improved transport and interfacial properties in the case of the polymer electrolytes and enhanced liquid retention capability in the case of the gel electrolytes. Finally, the use of the gel electrolytes for the development of new-design, plastic-like, lithium-ion batteries is illustrated.     

锂及锂离子蓄电池有机溶剂研究进展

从有机溶剂对电池安全性的影响，氧化稳定性，与负极的相容性及对电解液电导率的影响四个方面，论述了锂及锂离子蓄电池有机溶剂的化学和电化学，介绍了碳酸酯类，醚类和羧酸酯类溶剂的性质与电极的相容性及在有机电解液中的应用，对含硫，硼基及胺类有机溶剂等也作了论述。     

A novel PEO-based composite solid-state polymer electrolyte with methyl group-functionalized SBA-15 filler for rechargeable lithium batteries

Functionalized molecular sieve SBA-15 with trimethylchlorosilane was used as an inorganic filler in a poly(ethyleneoxide) (PEO) polymer matrix to synthesize a composite solid-state polymer electrolyte (CSPE) using LiClO₄ as the doping salts, which is designated to be used for rechargeable lithium batteries. The methyl group-functionalized SBA-15 (^fSBA-15) powder possesses more hydrophobic characters than SBA-15, which improves the miscibility between the ^fSBA-15 filler and the PEO matrix. The interaction between the ^fSBA-15 and PEO polymer matrix was investigated by scanning electron microscopy, X-ray diffraction, and differential scanning calorimetry. Linear sweep voltammetry and electrochemical impedance spectroscopy were employed to study the electrochemical stability windows, ionic conductivity, and interfacial stability of the CSPE. The temperature dependence of the change of the PEO polymer matrix in the CSPE from crystallization to amorphous phase was surveyed, for the first time, at different temperature by Fourier transform infrared emission spectroscopy. It has demonstrated that the addition of the ^fSBA-15 filler has improved significantly the electrochemical compatibility of the CSPE with a lithium metal electrode and enhanced effectively the ion conductivity of the CSPE. Dedicated to Professor Oleg Petrii on the occasion of his 70th birthday on August 24th, 2007.     

Novel siloxane polymers as polymer electrolytes for high energy density lithium batteries

A variety of disubstituted (double-comb) polysiloxane polymers have been prepared containing linear, branched, and cyclic oligoethyleneoxide units, –(OCH₂CH₂)_n–, in the side chains and as part of the siloxane backbone. Copolymers, using mixtures of linear ethylene oxide side chains, were also synthesized. These polymers were doped with LiN(SO₂CF₃)₂ (LiTFSI, 1) and conductivities of the polymer-salt complexes were determined as a function of temperature and doping level. The maximum conductivity of these polymers at 25 ° C was 2.99 ×10^–4, for a copolymer containing equimolar amounts of side chains with n = 5 and 6.     

Covalent organic frameworks for applications in lithium batteries

With the stone energy increasingly dried up and the environment polluted severely, developing renewable clean energy is already in extreme urgency. Exploiting new energy storage and transformation systems has progressively become the focal point in the energy research field. Covalent organic frameworks (COFs) have attracted extensive attention as a new kind of crosslinked polymers owing to the high crystallinity, excellent porosity, and favorable stability. The last decade has witnessed the great progress in crystalline COFs for the application in various arenas. The tailor-made functional skeleton together with well-defined periodical alignment has endowed COFs with enormous potential in lithium batteries. In this review, we initially illustrated the design principle of COFs for the application in lithium batteries. Furthermore, we made a comprehensive summary of the fast-developing COFs field in terms of lithium batteries, including lithium ion and lithium sulfur batteries. Finally, we discussed the remaining challenges and perspectives in this area and also proposed several possible future directions of development for lithium batteries. It is expected that this short review would contribute to the development of COFs materials in energy-related applications.     

Lithium-ion conducting electrolyte salts for lithium batteries

This paper presents an overview of the various types of lithium salts used to conduct Li(+) ions in electrolyte solutions for lithium rechargeable batteries. More emphasis is paid towards lithium salts and their ionic conductivity in conventional solutions, solid-electrolyte interface (SEI) formation towards carbonaceous anodes and the effect of anions on the aluminium current collector. The physicochemical and functional parameters relevant to electrochemical properties, that is, electrochemical stabilities, are also presented. The new types of lithium salts, such as the bis(oxalato)borate (LiBOB), oxalyldifluoroborate (LiODFB) and fluoroalkylphosphate (LiFAP), are described in detail with their appropriate synthesis procedures, possible decomposition mechanism for SEI formation and prospect of using them in future generation lithium-ion batteries. Finally, the state-of-the-art of the system is given and some interesting strategies for the future developments are illustrated.     

准固态锂离子电池正极材料柱[5]醌的研究

锂离子电池的有机正极材料由于具有比容量高、环境友好和廉价等优点,近年来成为研究的热点.但是,有机电极材料在液态电解液中的溶解流失易导致其容量迅速衰减,严重限制了它们的实际应用.本工作基于聚(甲基丙烯酸酯)/聚乙二醇的准固态电解质,考察了以柱[5]醌为正极的准固态锂二次电池的电化学性能.结果显示,柱[5]醌正极不仅保持了高容量的特性(首次放电容量410 mA h/g),并且循环寿命得到了有效提高.0.2 C下循环100周后,电极的容量保持率为88.5%,显示了柱[5]醌在高比能量准固态锂离子电池中的应用潜力.     

燃料电池聚合物电解质膜的研究进展

本文根据聚合物电解质膜燃料电池操作温度、使用的电解质和燃料的不同,将其分为高温质子交换膜燃料电池、低温质子换膜燃料电池、直接甲醇燃料电池和阴离子交换膜燃料电池,综述了它们所用电解质膜的最新进展.第一部分简要介绍了这4种燃料电池的优点和不足.第二部分首先介绍了Nafion膜的结构模型,并对平行柱状纳米水通道模型在介观尺度上进行了修正;接着分别对应用于不同燃料电池的改性膜的改性思路作了分析;最后讨论了用于不同燃料电池的新型质子交换膜的研究,同时列举了性能突出的改性膜和新型质子交换膜.第三部分介绍了阴离子交换膜的研究现状.第四部分对未来聚合物电解质膜的研究作了展望.     

锂离子电池低温性能改善研究进展

锂离子电池因其能量密度高,循环寿命长等优点已成为新型动力电池领域的研究热点,但其温度特性尤其是低温性能较差制约着锂离子电池的进一步使用. 本文综述了锂离子电池低温性能的研究进展,系统地分析了锂离子电池低温性能的主要限制因素. 从正极、电解液、负极三个方面讨论了近年来研究者们提高电池低温性能的改性方法. 并对提高锂离子电池低温性能的发展方向进行了展望.     

All solid polymer electrolytes based on polar side group rotation for rechargeable lithium batteries

A novel polymer matrix with a polar carbonyl group was designed and used to prepare an all‐solid polymer electrolyte in lithium rechargeable batteries. The ionic conductivity of this type of polymer electrolyte was examined. The relationship between the lithium salt concentration and ionic conductivity was investigated by Fourier transform infrared (FTIR) spectroscopy. The carbonyl groups in the polymer matrix effectively interacted with the lithium salt, which improved the ionic conductivity at a large range of temperatures. The ionic conductivity of this type of polymer electrolyte was approximately 10^?4 S cm^?1 at room temperature. The stability of the interface between electrode and electrolyte was evaluated by measuring the alternating current (AC) impedance. Copyright © 2009 John Wiley & Sons, Ltd.     

Recent progress of composite solid polymer electrolytes for all-solid-state lithium metal batteries

In comparison with lithium-ion batteries (LIBs) with liquid electrolytes, all-solid-state lithium batteries (ASSLBs) have been considered as promising systems for future energy storage due to their safety and high energy density. As the pivotal component used in ASSLBs, composite solid polymer electrolytes (CSPEs), derived from the incorporation of inorganic fillers into solid polymer electrolytes (SPEs), exhibit higher ionic conductivity, better mechanical strength, and superior thermal/electrochemical stability compared to the single-component SPEs, which can significantly promote the electrochemical performance of ASSLBs. Herein, the recent advances of CSPEs applied in ASSLBs are presented. The effects of the category, morphology and concentration of inorganic fillers on the ionic conductivity, mechanical strength, electrochemical window, interfacial stability and possible Li⁺ transfer mechanism of CSPEs will be systematically discussed. Finally, the challenges and perspectives are proposed for the future development of high-performance CSPEs and ASSLBs.     

Nano-crystalline FeOOH mixed with SWNT matrix as a superior anode material for lithium batteries

Nano-crystalline FeOOH particles(5～10 nm) have been uniformly mixed with electric matrix of single-walled carbon nanotubes(SWNTs)for forming FeOOH/SWNT composite via a facile ultrasonication method. Directly using the FeOOH/SWNT composite(containing 15 wt%SWNTs) as anode material for lithium battery enhances kinetics of the Li+insertion/extraction processes, thereby effectively improving reversible capacity and cycle performance, which delivers a high reversible capacity of 758 mAh g-1under a current density of 400 mA g-1even after 180 cycles, being comparable with previous reports in terms of electrochemical performance for FeOOH anode. The good electrochemical performance should be ascribed to the small particle size and nano-crystalline of FeOOH, as well as the good electronic conductivity of SWNT matrix.     

Nano-crystalline FeOOH mixed with SWNT matrix as a superior anode material for lithium batteries

Nano-crystalline FeOOH particles(5～10 nm) have been uniformly mixed with electric matrix of single-walled carbon nanotubes(SWNTs)for forming FeOOH/SWNT composite via a facile ultrasonication method. Directly using the FeOOH/SWNT composite(containing 15 wt%SWNTs) as anode material for lithium battery enhances kinetics of the Li+insertion/extraction processes, thereby effectively improving reversible capacity and cycle performance, which delivers a high reversible capacity of 758 mAh g-1under a current density of 400 mA g-1even after 180 cycles, being comparable with previous reports in terms of electrochemical performance for FeOOH anode. The good electrochemical performance should be ascribed to the small particle size and nano-crystalline of FeOOH, as well as the good electronic conductivity of SWNT matrix.     

Alkaline polymer electrolyte fuel cells: Principle, challenges, and recent progress

Polymer electrolyte membrane fuel cells (PEMFC) have been recognized as a significant power source in future energy systems based on hydrogen. The current PEMFC technology features the employment of acidic polymer electrolytes which, albeit superior to electrolyte solutions, have intrinsically limited the catalysts to noble metals, fundamentally preventing PEMFC from widespread deployment. An effective solution to this problem is to develop fuel cells based on alkaline polymer electrolytes (APEFC), which no...     

Polyacrylonitrile-based gel polymer electrolyte filled with Prussian blue forhigh-performance lithium polymer batteries

Lithium polymer batteries(LPBs) rely on a high ion transport to gain improved cell performance.Thermostable and porous gel polymer electrolytes(GPEs) have attracted much attention due to their excellent properties in electrolyte wettability and ionic conductivity.In this work,iron-nickel-cobalt trimetal Prussian blue analogue(PBA) nanocubes are filled into the electro spun polyacrylonitrile(PAN)-based membranes to generate GPE composites with morphological superiority consisting of fine fibers and interconnected pores.The thus obtained PBA@PAN fibrous membrane showcases good thermal stability,high porosity and electrolyte uptake,as well as a peak io nic conductivity of 2.7 mS/cm with the addition of 10% PBA,Consequently,the assembled lithium iron phosphate(LiFePO_4) battery using PBA@PAN-10 as the GPE delivers a high capacity of 152.2 mAh/g at 0.2 C and an ultralow capacity decay of0.09% per cycle in a long-te rm cycle life of 350 cycles at 1 C,endorsing its promising applications in LPBs.     

Solid-state electrochemical lithium cells with oxide electrodes and composite solid electrolyte

The LiClO₄-Al₂O₃ composite solid electrolyte and solid solutions LiFe _x Mn_2?x O₄ and Li₅Ti₄O₁₂ compositions are synthesized and their physicochemical properties are studied using the x-ray diffraction and electrical measurements. Based on composition 0.5LiClO₄-0.5Al₂O₃, whose conductivity is the highest, first experiments on the elaboration of model electrochemical solid-electrolyte lithium cells with LiMn₂O₄, LiFeMnO₄, LiFe_0.8Mn_0.2O₄, and Li₅Ti₄O₁₂ oxide spinel electrodes are performed.     

Recent progress in lithium-ion and lithium metal batteries

Moving towards carbon-free energy and global commercialization of electric vehicles stimulated extensive development in the field of lithium-ion batteries (LIBs), and to date, many scientific and technological advances have been achieved. The number of research works devoted to developing high-capacity and stable materials for lithium- ion and lithium metal batteries (LMBs) is constantly rising. This review covers the main progress in the development of LIBs and LMBs based on research works published in 2021. One of the main goals in the recent publications is to solve the problem of instability of layered nickel-rich lithium– nickel–cobalt–manganese oxides (Ni-rich NMC) cathodes, as well as silicon anodes. Improving the stability of NMC cathodes can be achieved by doping them with cations as well as by coating the oxides’ surfaces with protective layers (organic polymers and inorganic materials). The most effective strategies for dampening volumetric changes in silicon anodes include using porous silicon structures, obtaining composites with carbon, coating silicon-containing particles with inorganic or polymeric materials, and replacing standard binder materials. Much work has been devoted to suppressing dendrite formation in LMBs by forming stable coating layers on the surface of lithium metal, preparing composite anodes and alloys, and changing the composition of electrolytes. At the same time, in the field of electrolyte development, many research works have been devoted to the search for new hybrid polymer electrolytes containing lithium-conducting inorganic materials.     

Vanadium oxide gels as electrode materials for lithium batteries

Electrochemical lithium insertion has been studied in a large number of vanadium oxides with three dimensional framework structure. Several of these oxides have shown high capacities for lithium insertion and good reversibility.Pure solutions of decavanadic acid have shown to undergo spontaneous polycondensation reaction forming sols or gels of highly polymerized vanadium oxides, M _w 10⁶. After dehydration a series of xerogels with varying amounts of water, V₂O₅ · nH₂O, can be obtained. The structure of these xerogels consists of ribbons of corner and edge sharing VO₆ octahedra stabilized by interlayer water molecules. Under ambient conditions the water content corresponds to n=1.8, but this value can be reversibly changed under mild drying conditions.This report deals with the electrochemical insertion of lithium in dried vanadium oxide xerogels, with special regard to the use of these materials as electrodes in rechargeable lithium batteries.