锂离子电池硅基负极材料研究进展

本文主要介绍近年来硅及含硅材料作为锂离子电池负极材料的研究进展，包括硅单质、硅的氧化物以及硅的金属化合物和其它硅基多元化合物；分析了硅基材料作为锂离子电池负极材料存在的问题；阐述了硅基材料作为锂离子电池负极材料的研究前景。     

锂离子电池负极材料Li_4Ti_5O_(12)的制备及电化学性能

采用嵌段聚合物型表面活性剂P123作为结构导向剂,利用溶胶-凝胶方法制备出纳米TiO2作为合成Li4Ti5O12锂离子电池负极材料的原料之一.然后采用湿法球磨辅助的固相反应合成方法,以丙酮作为球磨介质,制备出Li4Ti5O12锂离子电池负极材科,并对所制备的Li4Ti5O12电极材料进行扫描电镜SEM、透射电镜TEM、粉末X射线衍射(XRD)、循环伏安(CV)以及循环性能测试.电化学性能测试表明所制各出的锂离子电池负极材料Li4Ti5O12具有较高的放电比容量和优异的循环性能.在电流密度为16 mA/g时首次放电比容量为155 mAh/g,首次库仑效率为98.3%.300次循环结束时放电比容量仍可达150.8 mAh/g,约为首次放电比容量的97.3%,300次循环容量仅衰减了2.7%.     

锂离子电池锡基负极材料研究进展

锡基负极材料容量高,安全性好,是目前动力锂离子电池用新型负极材料研究的热点。本文综述了近年来国内外在锂离子电池锡基各类负极材料方面的研究进展。重点介绍了它们的电极反应机理,材料合成方法及电化学性能,分析阐述了它们各自存在的优势和不足,总结了现有材料的改性手段。提出制备炭包覆锡基纳米颗粒的复合材料或者核壳、多孔等特殊结构的纳米级锡基材料,并在负极极片中预先引入金属锂,将是解决问题的最佳手段。指出锡基材料作为锂离子电池负极材料具有良好的商业化发展前景。     

低价铌氧化物电解电容器阳极的研制

采用Nb与Nb2O5固-固反应制备低价铌氧化物粉末,用正交试验法及方差分析对制备低价铌氧化物电解电容器阳极的工艺条件进行了优化。所研制的电容器阳极比容69500μF·V·g-1、损耗11.25%、漏电流(K值)1.8×10-4μA·μF-1·V-1,优于FTa16-300电容器钽粉国家标准(GB/T3136-1995)。     

硅基锂离子电池负极材料研究进展

作为锂离子电池负极材料,硅基材料具有较高的理论比容量、适中的嵌/脱锂电位、与电解液反应活性低等特点,成为最有前景的锂离子电池负极材料之一。然而由于其巨大的体积效应和较低的导电性导致其商业化应用具有相当的挑战性。本文综述了近年来为改善硅基材料的缺点而做的一些研究,展望了硅基材料作为锂离子电池负极材料的发展趋势。     

过渡金属氧/氮化物赝电容器电极材料的研究进展（英文）

法拉第赝电容器兼具二次电池高能量密度和超级电容器高功率密度的优点,而电极材料是决定法拉第赝电容器性能的关键。过渡金属氧化物/氮化物作为两种主要的赝电容器电极材料,能在提高能量密度的同时保持高功率密度。本文综述钌氧化物、镍氧化物、锰氧化物、钒氧化物、钴氧化物、铱氧化物等过渡金属氧化物和钛氮化物、钒氮化物、钼氮化物、铌氮化物等过渡金属氮化物的纳米结构设计和高比表面积复合材料制备的最新进展,为法拉第赝电容器电极材料的深入研究提供重要的借鉴意义。     

二元锰基复合金属氧化物锂离子电池负极材料的研究进展

在现有的各类锂离子电池(LIBs)负极材料中,二元锰基过渡金属氧化物材料(AMn_2O_4,A=Zn,Co,Ni等)已经被证明是较为理想的锂离子负极材料,以ZnMn_2O_4、CoMn_2O_4、NiMn_2O_4 3种负极材料为例,介绍了AMn_2O_4负极材料的储能机理、合成方法、以及结构-储锂性能之间构效关系,并提出了各材料目前存在的问题和相应的解决方案,以促进其在锂离子电池市场上的进一步推广和应用。     

无定形铌氧化膜的优化生长及机理分析

铌是用于制造电解电容器的优质材料，但在进行电解反应生长无定形Nb2O5电介质膜层的过程中会同时生成2种低价态的铌的氧化物（NbO，NbO2），影响了铌电容器的性能。本研究通过对影响无定形铌氧化膜生长的各种条件进行对比实验，并就生长机理进行了深入分析，较好地控制了氧化膜中3种氧化物的相对含量，改善了铌电容器的性能。     

锂钛氧嵌锂负极材料的研究进展

目前锂离子电池主要受制于安全性能、大功率性能和制造成本,新型高性能锂钛氧基负极材料有望解决这些问题,在动力型和储能型锂离子电池中获得应用。本文对Li4Ti5O12、Li Ti2O4、Li2Ti3O7、Li2Ti6O13等系列锂钛氧嵌锂化合物的晶体结构、电化学性能、制备方法、化学改性、应用研究等方面的重要成果进行了较全面的阐述,并指出了未来研究发展方向。     

锂离子电池正极材料LiχMn2O4电子结构的量子化学DV-Xα研究

采用原子基表示的第一原理赝势DV-α方法，计算了锂离子电池正极材料LiχMn2O4 (χ=0，1，2)各种模型的电子结构。结果表明：电极材料LiχMn2O4具有较好的电子导电性，锂离子嵌入正极材料后发生Jahn-Tell-er效应引起材料结构改变；锂离子的净电荷变为 0．7(χ=1)、 0．9或 0．5(χ=2)，说明锂离子过度嵌入LiχMn2O4中，导致部分锂离子和氧离子的相互作用增强，锂离子脱出较为困难，从而容量降低。最高占有轨道(HOMO)到最低空轨道(LUMO)的跃迁能很小，电子较易进行嵌入和脱出。     

Effects of volume strain due to Li–Sn compound formation on electrode potential in lithium-ion batteries

Sn and Sn-based compounds have attracted great interest as candidates for anode materials in lithium-ion batteries. Despite the great deal of attention focused on the effects of the volume change of the Sn anode during the lithiation/delithiation process on the cyclic property of the batteries, its influence on the electrode potential is still not well understood. In this study, by constructing a simple Sn–Li battery system, we have investigated the effects of the volume change associated with the formation of Li–Sn compounds on the electrode potential from the viewpoint of the Gibbs free energy and associated elastic-strain energy. Our experimental results show that (i) α-Sn, which is a low-temperature phase and in thermodynamic non-equilibrium at around 298 K (our experimental temperature), is also formed together with usual β-Sn after several cycles of the lithiation and delithiation processes and (ii) when a Sn plate-shape electrode is lithiated, the experimental electrode potential underruns the value expected thermodynamically. These experimental results can be consistently explained by considering the contribution of the elastic-strain energy to the chemical free energy of formation.     

Destabilization of Li-based complex hydrides

Fundamental researches on complex hydrides are recently of great importance to develop practical hydrogen storage materials with higher gravimetric hydrogen densities than those of conventional materials. First, in this paper, we clarify the correlation between B–H atomistic vibrations in [BH₄]⁻-anion and melting temperatures of MBH₄ (M=Li, Na, and K) as indexes of hydrogen desorption (decomposition) temperatures. This investigation implies that partial cation substitutions using smaller sized- and/or higher valenced-cations with higher electronegativities might provide higher energy modes of Raman spectra, and then, lower hydrogen desorption (decomposition) temperatures. Next, as an example, the hydrogen desorption properties of LiNH₂ and its partial cation substitution are preliminary examined. The starting and ending temperatures for the hydrogen desoprtion reaction are actually lowered about 50 K by the partial cation substitution of Li by Mg.     

High-performance anode materials for Na-ion batteries

Na-ion batteries are considered a promising alternative to Li-ion batteries for large-scale energy storage systems due to their low cost and the natural abundance of Na resource. Great effort is making worldwide to develop high-performance electrode materials for Na-ion batteries,which is critical for Na-ion batteries. This review provides a comprehensive overview of anode materials for Na-ion batteries based on Na-storage mechanism: insertion-based materials, alloy-based materials, conversion-based materials and organic composites. And we summarize the Nastorage mechanism of those anode materials and discuss their failure mechanism. Furthermore, the problems and challenges associated with those anodes are pointed out,and feasible strategies are proposed for designing highperformance anode materials. According to the current state of research, the search for suitable anode materials for Na-ion batteries is still challenging although substantial progress has been achieved. Nevertheless, we believe that high-performance Na-ion batteries would be promising for practical applications in large-scale energy storage systems in the near future.     

钙钛矿结构固体氧化物燃料电池阳极材料研究

钙钛矿型氧化物(ABO3)由于其混合导电能力及其在高温氧化还原气氛下具有较好电催化活性和化学稳定性,而且对硫、碳、氧具有良好的容耐性,因此被广泛应用于作为固体氧化物燃料电池的阳极材料.概述了阳极材料的特点及钙钛矿结构的阳极材料的进展情况,对钙钛矿结构的阳极材料的制备方法及性能进行了总结.     

锂离子电池用石墨负极材料改性研究进展

石墨是目前商业化锂离子电池应用最广的负极材料,日益增长的市场需求对石墨负极材料的储锂性能提出了更高的要求。概述了锂离子电池的工作原理和石墨嵌锂机制,针对石墨负极材料理论比容量(372 mA.h/g)较低和电解液兼容性较差等问题,总结了近年来石墨负极材料的改性手段,主要分为表面改性和结构调控等2类,其中表面改性技术包括氧化和卤化处理,特点是通过调控界面化学性质,可增强石墨结构的稳定性,促进稳定SEI膜的形成,但对于石墨储锂容量的提升非常有限;结构调控包括剥层法和缺陷构筑法,特点是通过扩大石墨层间距、降低石墨维度及在石墨结构上构筑缺陷,从而增加锂离子的活性位点,提供更多锂离子扩散通道,缓解循环过程中的体积变化,改善石墨与电解液的相容性,显著提升石墨的储锂性能。最后对石墨负极材料的未来发展趋势进行了展望。     

Alloy anodes for sodium-ion batteries

Sodium-ion batteries(SIBs) have emerged as one of the most promising candidates for next-generation energy storage systems because sodium is abundant in nature.The practical application of SIBs critically depends on developing robust electrode materials with high specific capacity and long cycling life,developing suitable anode materials is even more challenging.Alloy-type anodes are attractive for their high gravimetric and volumetric specific capacities,demonstrating great potential for high-energy SIBs,however,huge volume swelling hampered their practical application.Given the encouraging breakthroughs on alloy anodes for SIBs,herein,we present a review of the up-to-date progress and works carried out with alloy-based anode materials for SIBs.We review the synthetic strategies and their detailed electrochemical performance.In particular,we extensively reveal the important roles of alloy-based anodes in the development of SIBs.Research progress of alloy-type anodes and their compounds for sodium storage is summarized.Specific efforts to enhance the electrochemical performance of the alloy-based anode materials are discussed.Finally,we proposed multi-component alloys/high-entropy alloys(HEAs) as further research directions for alloy-based anodes.     

A Review of Metal Silicides for Lithium-Ion Battery Anode Application

Lithium batteries(LIBs) with low capacity graphite anode(～372 mAh g~(-1)) cannot meet the ever-growing demand for new energy electric vehicles and renewable energy storage.It is essential to replace graphite anode with higher capacity anode materials for high-energy density LIBs.Silicon(Si) is well known to be a possible alternative for graphite anode due to its highest capacity(～4200 mAh g~(-1)).Unfortunately,large volume change during lithiation and delithiation has prevented the Si anode from being commercialized.Metal silicides are a promising type of anode materials which can improve cycling stability via the accommodation of volume change by dispersing Si in the metal inactive/active matrix,while maintain greater capacity than graphite.Here,we present a classification of Si alloying with metals in periodic table of elements,review the available literature on metal silicide anodes to outline the progress in improving and understanding the electrochemical performance of various metal silicides,analyze the challenges that remain in using metal silicides,and offer perspectives regarding their future research and development as anode materials for commercial LIBs application.     

Improving Li Plating Behaviors Through Cu-Sn Alloy-Coated Current Collector for Dendrite-Free Lithium Metal Anodes

Alloy anode with good reversibility of lithium plating/stripping and long cycling stability is considered as promising anode materials.Here,Cu-Sn alloy is used as the substrate for Li deposition to induce the most densely packed arrangement of Li atoms,thus presenting high lithiophilicity and improving Li plating behaviors.The LiFePO_4-based full cell with the asprepared dendrite-free Li metal anode retained at 85 mAh g~(-1) with a high coulombic efficiency of 99.5% after 300 cycles,presenting a capacity retention of 79.4%.This strategy provides a new perspective to structure dendrite-free Li anode for the next-generation high-energy density batteries.