生物模板法合成锂离子电池电极材料研究进展

锂离子电池是一类极具潜力的新型二次化学储能器件,被广泛应用于便携式电子设备、电动交通工具和智能电网等领域。高性能电极材料的设计和合成是获得高能量密度、长循环寿命、高安全性锂离子电池的关键。文章针对锂离子电池电极材料存在制备工艺复杂、结构难以控制、活性物质利用率低、循环稳定性和倍率性能差等问题,从生物资源高效利用角度出发,结合生物材料尺寸均匀、形态多变、结构精密、环境友好等优点,综述了生物模板法合成锂离子电池电极材料的研究进展,并对该领域的发展方向进行了展望。     

纳米TiO2锂离子电池负极材料的溶剂热法制备及其电化学性能

本文采用溶剂热法,以四乙醇钛为主要原材料制备TiO2。结合X-射线衍射和扫描电镜等材料结构测试分析方法和恒电流充放电电化学测试技术,研究了添加表面活性剂聚乙烯吡咯烷酮(PVP)、溶剂热反应温度和高电导性气相生长碳纤维(VGCF)的添加对TiO2结构和电化学性能的影响。研究结果表明,本方法成功制备了纳米尺寸的锐钛矿TiO2,PVP的添加能改善TiO2颗粒的分散性。较低溶剂热反应温度下合成的TiO2颗粒尺寸较细,但团聚程度大,而较高的溶剂热反应温度使TiO2的颗粒尺寸长大,但团聚程度改善。通过添加表面活性剂、控制溶剂热温度和引入VGCF,本文获得的TiO2/C复合材料作为锂离子电池负极材料在1C、5C、10C和20C的放电倍率下容量分别可达220、180、150和120mAh/g,具有良好的倍率性能。     

高能量密度锂离子电池电极材料研究进展

高能量密度的电极活性材料是提高电芯能量密度的关键。提高锂离子电池能量密度的途径主要包括开发高比容量正负极材料和高放电电压平台正极材料。本研究综述了几种典型的具有高能量密度锂离子电池正、负极材料的最新研究进展,包括多电子反应、富锂、聚阴离子和镍锰酸锂正极材料以及硬碳、硅基和锡基负极材料,介绍了各种材料的特点和电化学性能,重点阐述了制备这些材料的典型方法和进展,并展望了高能量密度锂离子电池的发展方向和应用前景。     

模板法合成孔状纳米级锂离子电池正极材料LiFePO4

采用表面活性剂为模板,通过分子自组装法合成了孔状纳米级锂离子正极材料LiFePO4.并结合XRD、SEM、N2吸附/脱附和充放电测试等手段,对合成材料的结构、形貌、孔的分布和电化学性能进行了分析.实验结果表明:表面活性剂为模板,通过高温烧结脱去可以形成纳米孔状的LiFePO4正极材料,在以0.1mA的电流下放电,首次放电比容量有125.5mA·h/g,循环20次后其比容量仍有120mA·h/g,保持率达95.6%.     

水溶液锂离子电池电极材料的发展概况

通过对水溶液锂离子电池电极材料的制备方法、结构、电化学性能、充放电过程等方面的论述,总结了近年来水溶液锂离子电池电极材料的研究状况,并对存在的问题进行了分析。探讨了采用不同化合物、不同制备方法和改性方法来提高其比容量和循环稳定性的可能性。     

锂离子电池正负极材料研究

分析了国内外锂离子电池的研究发展比方平述了锂离子电池正负极材料的研究动 最新进展,提出了作为新一代锂离子电池的正负极材料的研究方向。     

锂离子电池正极材料热稳定性研究进展

对常见正极材料的热稳定性进行了综述,通过对正极材料的DSC数据的比较,可见表面包覆可以提高正极材料的热稳定性,原因是包覆材料能有效抑制活性材料和电解液的直接接触,减少热量的产生,提高电池的安全性.     

锂离子电池钒系电极材料的研究进展

锂离子电池电极材料对锂离子电池性能提升起着关键作用.钒的价态较多,构成的钒系电极材料具有层状、尖晶石型、反尖晶石型等多种结构.该系列材料通常具有较高的理论比容量,且合成方式多样,性价比高,因此钒系化合物在锂离子电池电极材料的应用上受到了广泛关注,但目前尚缺少对钒系电极材料的系统性总结.本文综述了以钒的氧化物、无锂型金属离子钒酸盐、含锂型钒酸盐及钒磷酸根聚阴离子材料为主要体系的锂离子电池钒系电极材料,并对各体系的结构及电化学性能进行了总结,针对合成锂离子电池钒系电极材料的主要方法(如固相合成法、溶胶-凝胶法、水热法、碳热还原法、液相沉淀法等)进行概述及分析,还对通过纳米化、特殊形貌控制、复合改性等其他改性方式优化的钒系电极材料的性能进行了介绍,最后对钒系锂离子电池电极材料的研究方向和发展前景进行展望,希望对促进该类材料的研究与产业化应用能有所助益.     

锂离子电池中钒氧化物电极材料的研究现状

综述了钒氧化物在锂离子电池中的应用,重点介绍了V₂O₅、V₆O₁₃、VO₂、V₃O₇、V₆O₁₄的结构、制备方法以及其锂离子电池的电化学性质,说明了V₄O₉、V₂O₃难在锂离子电池中应用的原因,讨论了钒氧化物作锂离子电池的正极材料的优点以及存在的问题,最后提出钒氧化物有希望成为实用的锂离子电池阴极材料.     

Microwave synthesis of electrode materials for lithium batteries

A novel microwave method is described for the preparation of electrode materials required for lithium batteries. The method is simple, fast and carried out in most cases with the same starting material as in conventional methods. Good crystallinity has been noted and lower temperatures of reaction has been inferred in cases where low temperature products have been identified     

化学气相沉积技术在锂离子电池电极材料中的应用

化学气相沉积(CVD)是近年来发展起来的制备各种无机复合材料的一种新技术.简要介绍了CVD技术的原理和特点,分析了目前研究的各种锂离子电池正负极材料存在的问题,重点介绍了CVD技术在解决这些问题上的应用进展.     

Recent progress in electrode materials produced by spray pyrolysis for next-generation lithium ion batteries

We review the effect that various structures and composites synthesized by spray pyrolysis have on the electrochemical performance of next-generation electrodes for medium and large lithium ion batteries. The morphologies of electrode particles in particular have a strong influence on the capacity, power, safety, and cycle life. Recent progress in improving the electrochemical performance of electrodes is provided with a particular focus on electrodes composed of nanoparticles, core–shell or yolk–shell structures, and carbon-based composites. Finally, we propose a direction for future research for high-performance lithium ion batteries incorporating fabrication by spray pyrolysis.     

Electrode materials for lithium secondary batteries prepared by sol-gel methods

Since the commercialization of lithium secondary batteries in the early of 1990s, their development has been rapid. Nowadays, improving the preparation technology and electrochemical performance of their electrode materials is a major focus in research and development of the materials, power sources and chemistry. Sol-gel methods are a promising way to prepare electrode materials due to their evident advantages over traditional methods, for example, homogeneous mixing at the atomic or molecular level, lower synthesis temperature, shorter heating time, better crystallinity, uniform particle distribution and smaller particle size at nanometer level. In this paper, latest progress in the preparation of electrode materials by sol-gel methods is reviewed, including cathodic ones, e.g., lithium cobalt oxides, lithium nickel oxides, spinel and layered lithium manganese oxides, vanadium oxides and ferrous phosphates, and anodic ones, e.g., tin oxides and titanium oxides. Compared with those prepared by traditional solid-state reaction, the structure stability of the prepared electrode materials and the behavior of lithium intercalation and de-intercalation are much improved. As a result, the prepared products provide better electrochemical performance including reversible capacity, cycling behavior and rate capability. In addition, sol-gel methods can be used to prepare new kinds of electrode materials such as nanowires of LiCoO₂ and nanotubes of V₂O₅, which cannot be easily created by the traditional methods. Further development and application of sol-gel methods will bring about new and better electrode materials, meaning a great promotion to lithium secondary batteries.     

锂离子二次电池负极材料的研究综述

总结了在碳材料、合金材料和复合材料等3个锂离子电池负极材料研发的主导方向上的开发情况和它们各自特点,描述了目前的研究所面临难题,给出了锂离子电池负极材料研发取得重大突破的可能途径和建议.     

Nanostructured electrode materials for Ni-MH x batteries prepared by mechanical alloying

Nanocrystalline TiFe- and Mg₂Ni-type alloys were prepared by mechanical alloying followed by annealing. The structure and electrochemical properties of these materials were studied. The properties of hydrogen host materials can be modified substantially by alloying to obtain the desired storage characteristics. It was found that the respective replacement of Fe in TiFe by Ni and Mn improved not only the discharge capacity but also the cycle life of these electrodes. On the other hand, a partial substitution of Mg by Mn in Mg_2?x M _x Ni alloy leads to an increase in discharge capacity, at room temperature. Furthermore, the effect of the nickel and graphite coating on the structure of the nanocrystalline alloys and the electrodes characteristics were investigated. In Mg₂Ni-type alloy mechanical coating with graphite effectively reduced the degradation rate of the studied electrode materials.     

Surface modification of cathode materials for lithium ion batteries

We have studied the effect of surface modification with aluminum hydroxide and alumina-boehmite mixtures on the electrochemical performance of an equimolar LiCoO₂/LiMn₂O₄ composite cathode material. A process has been developed for the deposition of aluminum hydroxide nanocoatings using ultrasonic processing. Al(OH)₃ nanocoatings, as well as alumina-boehmite nanocoatings, considerably improve the cyclability of the composite in an extended voltage range (up to 4.5 V) in comparison with the unmodified material, with an insignificant reduction in specific capacity in the first cycles. Both types of coatings markedly improve the cyclability of the composite at high current rates in comparison with the unmodified composite.     

Molten-salt decomposition synthesis of SnO2 nanoparticles as anode materials for lithium ion batteries

SnO₂ nanoparticles were synthesized by a simple, easily scaled-up molten-salt decomposition method with SnSO₄ as the molten salt and the reactive phase. During the synthesis process, the undecomposed molten SnSO₄ makes it possible to obtain SnO₂ nanoparticles by serving as the dispersion medium and keeping the particles from aggregation. The as-prepared SnO₂ had a tetragonal rutile structure with an average particle size of 50 nm. When used as anode materials for lithium ion battery, SnO₂ nanoparticles retained the charge capacity still as high as 402 mAh g^? 1 at a current density of 156 mA g^? 1 after 40 cycles. Moreover, cyclic voltammograms tests showed the formation/deformation of Li₂O was partially reversible.     

Nanosized LiFePO4 cathode materials for lithium ion batteries

In this study, we prepared nano-particles of LiFePO4 as cathode material for lithium ion batteries by the solid-state reaction. A simple one-step heat treatment has been employed with control of heating temperature and heated LiFePO4 at 650 degrees C exhibited higher 125 mA h/g of the discharge capacity than 600 degrees C, 700 degrees C. To improve conductivity of the inter-particle, carbon coating was carried out by raw carbon or pyrene as carbon sources and their morphological properties of particles on the carbon coating was compared with by FE-SEM, TEM. From the FE-SEM results, the particles of carbon added LiFePO4 have much smaller size than LiFePO4 as below 300 nm. When adding pyrene (10 wt%), the carbon surrounded non-uniformly with surface of the particles compared with adding raw carbon which wrapped uniformly with carbon web and it was exhibited 152 mA h/g of the discharge capacity on LiFePO4/C composite cells at 10th cycle.     

炭材料在锂金属电池中应用进展

金属锂作为下一代高能量密度电池的负极材料,具有广阔的应用前景.然而,金属锂的沉积/剥离过程常伴随着高曲折度的枝晶的形成,导致电池寿命短,甚至会诱发安全隐患.迄今为止,研究者们已开发出多种方法来抑制枝晶生长和调节固体电解质界面膜的均匀性.炭材料因其轻质、高导电、多级多孔、化学和物理稳定特性被设计成不同种类的材料来用于稳定...