Effect of Transition Metal on the Electrochemical Performances of Some Intermetallic Anodes for Lithium Ion Batteries

Some transition metal antimonides were prepared by levitation melting and subsequent ball-milling. The electrochem-ical behaviors of these materials as new candidate negative electrode materials in lithium ion secondary batteries wereinvestigated. It was found that they exhibited significantly larger volumetric capacity than carbon-based materi-als. The formation and composition of solid electrolyte interface (SEI) film were characterized by electrochemicalimpedance spectroscopy (EIS) and Fourier transform infra-red (FTIR) spectroscopy.     

CTAB辅助水热合成球状纳米花MoS2/C复合材料及其电化学性能研究

以钼酸钠(Na₂MoO₄·2H₂O)、硫脲(NH₂CSNH₂)、CTAB为原料, 利用水热法合成了MoS₂/C球状纳米花复合材料。通过XRD、SEM、TEM、TG等分析测试方法, 研究了不同CTAB添加量对MoS₂/C复合材料的微观结构、表面形貌的影响规律, 结果显示, 有部分无定形碳嵌入了MoS₂层间, 并抑制了MoS₂(002)面的堆积。电化学测试表明: 与纯MoS₂相比, MoS₂/C复合材料具有更好的电化学性能, 当加入0.025 g CTAB时首次放电比容量达到730 mAh/g, 在100 mA/g的电流密度下经过100次循环比容量稳定在415 mAh/g。在此基础上讨论了MoS₂/C球状纳米花复合材料的可能生长机理以及对材料电化学性能的影响规律。     

Nanostructured Silicon Anodes for Lithium Ion Rechargeable Batteries

Rechargeable lithium ion batteries are integral to today's information‐rich, mobile society. Currently they are one of the most popular types of battery used in portable electronics because of their high energy density and flexible design. Despite their increasing use at the present time, there is great continued commercial interest in developing new and improved electrode materials for lithium ion batteries that would lead to dramatically higher energy capacity and longer cycle life. Silicon is one of the most promising anode materials because it has the highest known theoretical charge capacity and is the second most abundant element on earth. However, silicon anodes have limited applications because of the huge volume change associated with the insertion and extraction of lithium. This causes cracking and pulverization of the anode, which leads to a loss of electrical contact and eventual fading of capacity. Nanostructured silicon anodes, as compared to the previously tested silicon film anodes, can help overcome the above issues. As arrays of silicon nanowires or nanorods, which help accommodate the volume changes, or as nanoscale compliant layers, which increase the stress resilience of silicon films, nanoengineered silicon anodes show potential to enable a new generation of lithium ion batteries with significantly higher reversible charge capacity and longer cycle life.     

Key Aspects of Lithium Metal Anodes for Lithium Metal Batteries

Rechargeable batteries are considered promising replacements for environmentally hazardous fossil fuel‐based energy technologies. High‐energy lithium‐metal batteries have received tremendous attention for use in portable electronic devices and electric vehicles. However, the low Coulombic efficiency, short life cycle, huge volume expansion, uncontrolled dendrite growth, and endless interfacial reactions of the metallic lithium anode are major obstacles in their commercialization. Extensive research efforts have been devoted to address these issues and significant progress has been made by tuning electrolyte chemistry, designing electrode frameworks, discovering nanotechnology‐based solutions, etc. This Review aims to provide a conceptual understanding of the current issues involved in using a lithium metal anode and to unveil its electrochemistry. The most recent advancements in lithium metal battery technology are outlined and suggestions for future research to develop a safe and stable lithium anode are presented.     

锂离子电池正极材料LiNi-x-yCoxMnyO2的研究现状

正极材料对锂离子电池的性能和价格具有决定性的作用，对正极材料的研究一直是锂离子电池研究中的热点。主要对一类新型正极材料LiNi-x-yCoxMnyO2的国内外研究现状进行了综述，并比较了不同合成方法对其电化学性能的影响，最后对这类正极材料的研究给予了展望。     

锂离子电池炭负极材料结构及嵌锂机理研究进展

炭材料取代金属锂作为负极后,锂离子电池在商业应用上取得了成功,并以其高能量密度在各种电子设备上广泛使用.锂离子电池的性能很大程度上取决于炭负极材料的微观结构,不同种类的炭材料其电化学性能有很大差别.对近几年所研究的可逆储锂炭材料进行了综述,着重总结了炭负极材料的种类、结构及其嵌锂机理,并展望了锂离子电池炭负极材料的研究进展.     

Molecular Design of the Solid Copolymer Electrolyte- Poly(styrene-b-ethylene oxide) for Lithium Ion Batteries

Poly(ethylene oxide) (PEO) is a commonly used electrolytic polymer in lithium ion batteries because of its high viscosity which allows fabricating thin layers. However, its inherent low ionic conductivity must be enhanced by the addition of highly conductive salt additives. Also its weak mechanical strength needs a complementary block, such as poly(styrene) (PS), to strengthen the electrolytic membrane during charging/discharging processes. PS is a strong material to complement the PEO and to create a reinforced copolymer electrolyte termed as the poly(styrene-b-ethylene oxide) (PS-PEO). In this work, molecular dynamics simulations are employed to study the effects of doping the PS constituents into the PEO based copolymer electrolyte. The results reveal that strengthening the mechanical strength increases the intra conjugation forces which penalize the ionic conductivity. Hence both ionic conductivity and mechanical strength of the copolymer have to be compromised. This paper designs the optimized molecular structure through the atomistic analysis instead of try-and-error experiments.     

Synthesis of MoS2@C Nanotubes Via the Kirkendall Effect with Enhanced Electrochemical Performance for Lithium Ion and Sodium Ion Batteries

A MoS₂@C nanotube composite is prepared through a facile hydrothermal method, in which the MoS₂ nanotube and amorphous carbon are generated synchronically. When evaluated as an anode material for lithium ion batteries (LIB), the MoS₂@C nanotube manifests an enhanced capacity of 1327 mA h g^?1 at 0.1 C with high initial Coulombic efficiency (ICE) of 92% and with capacity retention of 1058.4 mA h g^?1 (90% initial capacity retention) after 300 cycles at a rate of 0.5 C. A superior rate capacity of 850 mA h g^?1 at 5 C is also obtained. As for sodium ion batteries, a specific capacity of 480 mA h g^?1 at 0.5 C is achieved after 200 cycles. The synchronically formed carbon and stable hollow structure lead to the long cycle stability, high ICE, and superior rate capability. The good electrochemical behavior of MoS₂@C nanotube composite suggests its potential application in high‐energy LIB.     

A Mini-Review on Metal Recycling from Spent Lithium Ion Batteries

The rapid growth of lithium ion batteries (LIBs) for portable electronic devices and electric vehicles has resulted in an increased number of spent LIBs. Spent LIBs contain not only dangerous heavy metals but also toxic chemicals that pose a serious threat to ecosystems and human health. Therefore, a great deal of attention has been paid to the development of an efficient process to recycle spent LIBs for both economic aspects and environmental protection. In this paper, we review the state-of-the-art processes for metal recycling from spent LIBs, introduce the structure of a LIB, and summarize all available technologies that are used in different recovery processes. It is notable that metal extraction and pretreatment play important roles in the whole recovery process, based on one or more of the principles of pyrometallurgy, hydrometallurgy, biometallurgy, and so forth. By further comparing different recycling methods, existing challenges are identified and suggestions for improving the recycling effectiveness can be proposed.     

Ti‐Based Oxide Anode Materials for Advanced Electrochemical Energy Storage: Lithium/Sodium Ion Batteries and Hybrid Pseudocapacitors

Titanium‐based oxides including TiO₂ and M‐Ti‐O compounds (M = Li, Nb, Na, etc.) family, exhibit advantageous structural dynamics (2D ion diffusion path, open and stable structure for ion accommodations) for practical applications in energy storage systems, such as lithium‐ion batteries, sodium‐ion batteries, and hybrid pseudocapacitors. Further, Ti‐based oxides show high operating voltage relative to the deposition of alkali metal, ensuring full safety by avoiding the formation of lithium and sodium dendrites. On the other hand, high working potential prevents the decomposition of electrolyte, delivering excellent rate capability through the unique pseudocapacitive kinetics. Nevertheless, the intrinsic poor electrical conductivity and reaction dynamics limit further applications in energy storage devices. Recently, various work and in‐depth understanding on the morphologies control, surface engineering, bulk‐phase doping of Ti‐based oxides, have been promoted to overcome these issues. Inspired by that, in this review, the authors summarize the fundamental issues, challenges and advances of Ti‐based oxides in the applications of advanced electrochemical energy storage. Particularly, the authors focus on the progresses on the working mechanism and device applications from lithium‐ion batteries to sodium‐ion batteries, and then the hybrid pseudocapacitors. In addition, future perspectives for fundamental research and practical applications are discussed.     

锂离子电池负极材料二氧化锡的研究进展

作为一种新型锂离子电池负极材料,二氧化锡由于具有高比容量、低嵌锂电势等优点而受到了广泛关注。但是二氧化锡在充放电循环中体积变化过大,导致其不可逆容量损失大、循环性能较差。纳米化和合金化是解决这一问题的有效途径。综述了纳米结构二氧化锡及其复合材料,特别是二氧化锡纳米线、纳米棒、纳米管、纳米片等与无定形碳、碳纳米管、石墨烯的复合材料在锂离子电池负极材料中的研究进展,并展望了其应用前景。     

Ternary Sn–Ti–O Based Nanostructures as Anodes for Lithium Ion Batteries

SnO_x (x = 0, 1, 2) and TiO₂ are widely considered to be potential anode candidates for next generation lithium ion batteries. In terms of the lithium storage mechanisms, TiO₂ anodes operate on the base of the Li ion intercalation–deintercalation, and they typically display long cycling life and high rate capability, arising from the negligible cell volume change during the discharge–charge process, while their performance is limited by low specific capacity and low electronic conductivity. SnO_x anodes rely on the alloying–dealloying reaction with Li ions, and typically exhibit large specific capacity but poor cycling performance, originating from the extremely large volume change and thus the resultant pulverization problems. Making use of their advantages and minimizing the disadvantages, numerous strategies have been developed in the recent years to design composite nanostructured Sn–Ti–O ternary systems. This Review aims to provide rational understanding on their design and the improvement of electrochemical properties of such systems, including SnO_x–TiO₂ nanocomposites mixing at nanoscale and nanostructured Sn_xTi_1‐xO₂ solid solutions doped at the atomic level, as well as their combinations with carbon‐based nanomaterials.     

The Application of Hollow Structured Anodes for Sodium‐Ion Batteries: From Simple to Complex Systems

Hollow structures exhibit fascinating and important properties for energy‐related applications, such as lithium‐ion batteries, supercapacitors, and electrocatalysts. Sodium‐ion batteries, as analogs of lithium‐ion batteries, are considered as promising devices for large‐scale electrical energy storage. Inspired by applications of hollow structures as anodes for lithium‐ion batteries, the application of these structures in sodium‐ion batteries has attracted great attention in recent years. However, due to the difference in lithium and sodium‐ion batteries, there are several issues that need to be addressed toward rational design of hollow structured sodium anodes. Herein, this research news article presents the recent developments in the synthesis of hollow structured anodes for sodium‐ion batteries. The main strategies for rational design of materials for sodium‐ion batteries are presented to provide an overview and perspectives for the future developments of this research area.     

锂离子电池Si/C/石墨复合负极材料的电化学性能

采用热裂解方法, 热解分散于聚偏二氟乙烯溶液中的硅和石墨, 得到了具有稳定电化学循环性能的Si/C/石墨复合负极材料。透射电子显微镜观察发现, 复合材料形貌为无定型碳包裹硅颗粒的核壳结构。通过系统研究不同Si粒径和石墨含量对电极电化学性能的影响, 发现Si颗粒粒径越小复合材料电化学循环稳定性能越优越, 适当的降低石墨含量有利于电极材料剩余比容量的提高。当Si粒径为50 nm, Si与石墨质量比1:1时, 电极材料具有1741.6 mAh/g的首次放电比容量和72.5%的首次库仑效率, 60次循环后, 可逆比容量保持在820 mAh/g。热解有机物形成碳包覆的结构能有效地改善硅基类负极材料的电化学循环性能。     

锂离子电池正极材料的研制新进展

综述了锂离子电池正极材料的最近发展动态,着重介绍了被修饰的正极材料、O3-LiCoO2、LiFeO2的合成方法及电化学性能。展望了锂离子正极材料的发展趋势。