镁-过渡金属复合物正极材料

高能量密度、大容量、高工作电压、低成本、环境友好的二次电池是未来储能电池技术的发展方向。高比能的镁离子电池（MIBs）是以镁或镁合金为负极的二次电池,是一种重要的有望用于电动汽车的新型绿色储能电池。镁离子电池发展缓慢的主要问题是镁离子在正极材料中扩散速度慢。因此,本文综述了五类晶体结构的镁-过渡金属复合物类型（包括一维隧道结构、二维层状结构、三维尖晶石结构、三维NASICON结构、三维橄榄石结构）、制备方法、电化学性能等,还阐述了镁离子在固体中扩散行为及提高扩散速度的措施,最后展望了镁离子电池正极材料镁-过渡金属复合物的重要研究方向。寻找高电压（大于3 V）、高比能量、高可逆性的正极材料和与其匹配的电解液是实现镁离子电池第三次突破的关键。我们希望本文有利于更深入地了解镁离子电池正极材料,促进镁离子电池的发展。     

具有三维导电网络结构的锡纳米颗粒/石墨烯纳米片复合电极材料的储镁性能研究

镁二次电池具有安全性高、价格低廉等优点,是一种具有潜在应用前景的高能量密度电池体系.目前,镁二次电池的研究重点之一是寻找合适的电极材料.最近,我们通过水热和热处理相结合的方法成功制备了具有三维导电网络结构的锡纳米颗粒/石墨烯纳米片复合电极材料.研究发现,在石墨烯的三维导电网络片层上,均匀分布了粒径小于100 nm的锡纳米颗粒.将锡纳米颗粒/石墨烯纳米片复合材料作为镁二次电池电极材料,当电流密度为15 mA·g^-1和300 mA·g^-1时,首次放电容量分别达到了545.4 mAh·g^-1和238.8 mAh·g^-1,经过150圈后,容量保持率达到了93%,库伦效率为99%,表现出了较高的电化学活性.研究还发现,镁离子嵌入复合材料中形成镁锡合金,当镁离子脱出后,再次形成锡纳米颗粒/石墨烯纳米片复合电极材料,镁离子的脱出和嵌入具有很高的可逆性.这对未来研究设计高性能镁离子电极材料具有十分重要的意义.     

二次电池研究进展

能源的存储和利用是当今科学和技术发展中的重大课题之一,尤其是作为高效的电能/化学能转化装置的二次电池相关技术一直是科学家研究的热点领域。在此背景下,本文较为系统地介绍目前二次电池的重要研究进展,将从二次电池的发展历史引入,再到其相关的基础理论知识的介绍。随后较为详细地讨论当前不同体系的二次电池及相关应的关键材料的研究进展,涉及到锂离子电池、钠离子电池、钾离子电池、镁离子电池、锌离子电池、钙离子电池、铝离子电池、氟离子电池、氯离子电池、双离子电池、锂-硫(硒)电池、钠-硫(硒)电池、钾-硫(硒)电池、多价金属-硫基电池、锂-氧电池、钠-氧电池、钾-氧电池、多价金属-氧气电池、锂-溴(碘)电池、水系金属离子电池、光辅助电池、柔性电池、有机电池、金属-二氧化碳电池等。此外,也介绍了电池研究中常见的电极反应过程表征技术,包括冷冻电镜、透射电镜、同步辐射、原位谱学表征、磁性表征等。本文将有助于研究人员对二次电池进行全面系统的了解与把握,并为之后二次电池的研究提供很好的指导作用。     

具有三维导电网络结构的锡纳米颗粒/石墨烯纳米片复合电极材料的储镁性能研究（英文）

镁二次电池具有安全性高、价格低廉等优点,是一种具有潜在应用前景的高能量密度电池体系.目前,镁二次电池的研究重点之一是寻找合适的电极材料.最近,我们通过水热和热处理相结合的方法成功制备了具有三维导电网络结构的锡纳米颗粒/石墨烯纳米片复合电极材料.研究发现,在石墨烯的三维导电网络片层上,均匀分布了粒径小于100 nm的锡纳米颗粒.将锡纳米颗粒/石墨烯纳米片复合材料作为镁二次电池电极材料,当电流密度为15 mA·g~(-1)和300 mA·g~(-1)时,首次放电容量分别达到了545.4 mAh·g~(-1)和238.8 mAh·g~(-1),经过150圈后,容量保持率达到了93%,库伦效率为99%,表现出了较高的电化学活性.研究还发现,镁离子嵌入复合材料中形成镁锡合金,当镁离子脱出后,再次形成锡纳米颗粒/石墨烯纳米片复合电极材料,镁离子的脱出和嵌入具有很高的可逆性.这对未来研究设计高性能镁离子电极材料具有十分重要的意义.     

可充电镁电池负极改性策略

可充电镁电池具有理论体积比容量大、 地壳丰度高、 成本低、 环境友好及更为安全等优点, 是未来高能量存储系统发展的重要方向之一. 在大多数传统电解液中, 镁金属负极表面形成的钝化膜会阻碍镁的可逆沉积溶解过程, 从而限制了可充电镁电池的商业化应用. 由于存在成本高、 合成步骤复杂、 离子电导率低及难以同时与正负极兼容等问题, 聚焦于解决镁负级钝化问题的电解液研究陷入瓶颈. 因此, 通过对镁电池负极进行修饰改性, 使其在传统电解液中实现可逆过程是一种具有发展前景的策略. 本文从合金负极及人工界面形成两方面总结了近年来用于可充电镁电池负极改性的策略, 并在分析对比的基础上提出了进一步发展的结论和展望.     

二硒化钼纳米球储锂和储镁的性能和机理研究

二硒化钼是一种二维过渡金属硫族化合物材料,凭借其具有较快的离子迁移率、较弱的范德华力的层状结构,在锂离子电池的应用研究中吸引了广泛的关注。同时在镁离子电池应用中表现出潜在的研究前景。然而,有关二硒化钼在锂离子电池中的报道多集中在如何提高储锂性能上,对其离子存储机理缺乏深入研究。此外,在储镁性能和机理上均没有报道。本项工作通过湿化学和高温煅烧两步法合成了二硒化钼纳米球,当二硒化钼纳米球用作锂离子电池负极材料时,在5 A·g^-1的电流密度下展示了高于100 mAh·g^-1的优异高倍率容量;同时,作为镁离子电池正极材料时,在20 mA·g^-1的电流密度下表现出了120 mAh·g^-1的高储镁可逆容量。另外,通过电化学、原位和非原位X射线衍射表征技术,分别揭示了二硒化钼纳米球低平台发生的转化式和高平台发生的类锂硒电池反应并存的储锂机理,以及赝电容式为主,嵌入式为辅的储镁机理。本项工作不仅为二维过渡金属硫族化合物材料的储锂机理提供了深刻的理解,同时也为新型层状储能材料的设计开发提供了方向。     

可充镁电池电解液

由于金属镁具有能量密度较高、价格低、操作安全等优点,可充镁电池是在大负荷储能方面极具发展潜力的二次电池。本文综述了可充镁电池电解液的研究进展,其中包括溶于醚溶剂中的格氏试剂、Mg(BR₂R′₂)₂(其中R、R′为烷基或芳基)、Mg(AX_4-nR_n′R′_n″)₂络合物(其中A=Al、B、Sb、P、As、Fe和Ta等,X =Cl、Br和F,R、R′为烷基或芳基,0相似文献   

PP14TFSI离子液体在可充镁电池电解液的应用

制备了可充镁电池电解质苯酚基镁盐,以四氢呋喃（THF）与N-甲基-N-丁基-哌啶-双三氟甲基磺酰胺（PP14TFSI）离子液体混合物代替四氢呋喃作为该电解质的溶剂. 当THF与PP₁₄TFSI体积配比为1:1时,该苯酚基镁盐电解液镁可逆溶出性能最佳,电化学窗口宽（2.7 V vs. Mg）,离子电导率高（7.77 mS·cm^-1）. 此外,热重测试表明离子液体的加入大大降低了THF溶剂的挥发性,提高了可充镁电池的安全性能. 四氢呋喃 + N-甲基-N-丁基-哌啶-双三氟甲基磺酰胺混合溶剂有望作为可充镁电池电解液的首选溶剂.     

镁二次电池材料的国内外研究现状

综述了镁二次电池材料的国内外研究现状.从Mg电极在不同的电解质溶液中的电化学行为来看,除了获得一致好评的电解质Mg(AlCl2BuEt)2/THF外,国内研究了Mg(SnPh3)2/THF的性能,又尝试了复合电解质(PP13-TFSI)和(BMIMBF4)的混合,都很好得获得可逆的Mg的沉积和溶解.目前,国内、外对镁电池用的聚合物电解质(GPE)有了进一步的研究.利用PNA(聚丙烯腈)、PMMA(聚甲基丙烯酸甲酯)、PVDF(聚偏氟乙烯)和PC、EC、MgTr混合制备了GPE,同时日本合成的(PEO-PMA)-(EC-DMC)/Mg[(CF3SO2)2N]2(x-y)和PEO-PMA)-a mol%Mg(TFSI)2/EMITFSI(x-y),和韩国合成的P(VdF-co-HFP)其电导都大于10-4S·cm-1.虽然组装电池的循环性能不是很理想,但说明了GPE同样可以应用在镁电池中.从Mg正极材料的报道来看,目前大部分工作都是在开发钠米管、层状和复合材料.比如VOx/钛酸盐纳米棒、VXG/PANI复合物、VOx/PANI NCs、Cu0.1-doped VOx-NTs等,都有很好的首次放电比能量,循环性能不好的主要原因是镁负极钝化.上海交通大学尝试研究把的导电含硫材料/聚苯胺复合物做为正极材料,并组装成钮扣电池,其采用的电解质为0.25 M的Mg(AlCl2BuEt)2/THF.该钮扣电池多次循环之后放电比能量也可以达到72.7mAh/g,和锂离子电池相比,该复合物显示了较慢的Mg插入速率和较低的放电比容量,但实验结果已足够说明了导电含硫材料/聚苯胺复合物做为镁二次电池正极材料的可行性.目前紧迫的任务是,开发新型的正、负极材料,降低镁钝化电解质,开发新的负极材料,比如嵌入式的或合金负极材料.研究结果表明镁二次电池有着非常好的开发前景.     

分级结构氮掺杂碳纳米笼:高倍率长寿命可充电镁电池正极材料

可充电镁电池成本低、安全性好,是非常有前景的下一代二次电池,其关键之一是开发高性能的正极材料.本工作首次利用分级结构氮掺杂碳纳米笼（hNCNC）作为可充电镁电池的正极材料,展现出高放电比容量（71 mAh·g^-1@100 mA·g^-1）、优异的倍率性能（60 mAh·g^-1@2000 mA·g^-1）和长循环稳定性（1000圈容量保留率83%@1000 mA·g^-1）.hNCNC呈现电容行为主导的储镁机制,理论研究表明镁离子主要吸附在微孔边缘的碳原子、吡啶氮或吡咯氮等活性位点上.其优异储镁性能可归因于：（1） hNCNC的大比表面积（1590 m²·g^-1）、丰富微孔缺陷和高吡啶/吡咯氮含量（4.49 at.%）有效提升了储镁容量;（2） hNCNC的高导电性、多级孔道结构及N掺杂导致的高浸润性有利于电荷传输,降低了电池的等效串联电阻,从而改善了倍率性能;（3） hNCNC的稳定碳骨架结构及其表面吸附储镁机制使其具有优异的长循环稳定性.     

Nonaqueous magnesium electrochemistry and its application in secondary batteries

A revolution in modern electronics has led to the miniaturization and evolution of many portable devices, such as cellular telephones and laptop computers, since the 1980s. This has led to an increasing demand for new and compatible energy storage technologies. Furthermore, a growing awareness of pollution issues has provided a strong impetus for the science and technology community to develop alternatives with ever-higher energy densities, with the ultimate goal of being able to propel electric vehicles. Magnesium's thermodynamic properties make this metal a natural candidate for utilization as an anode in high-energy-density, rechargeable battery systems. We report herein on the results of extensive studies on magnesium anodes and magnesium insertion electrodes in nonaqueous electrolyte solutions. Novel, rechargeable nonaqueous magnesium battery systems were developed based on the research. This work had two major challenges: one was to develop electrolyte solutions with especially high anodic stability in which magnesium anodes can function at a high level of cycling efficiency; the other was to develop a cathode that can reversibly intercalate Mg ions in these electrolyte systems. The new magnesium batteries consist of Mg metal anodes, an electrolyte with a general structure of Mg(AlX(3-n)R(n)R')(2) (R',R = alkyl groups, X = halide) in ethereal solutions (e.g., tetrahydrofuran, polyethers of the "glyme" family), and Chevrel phases of MgMo(3)S(4) stoichiometry as highly reversible cathodes. With their practical energy density expected to be >60 Wh/Kg, the battery systems can be cycled thousands of times with almost no capacity fading. The batteries are an environmentally friendly alternative to lead-acid and nickel-cadmium batteries and are composed of abundant, inexpensive, and nonpoisonous materials. The batteries are expected to provide superior results in large devices that require high-energy density, high cycle life, a high degree of safety, and low-cost components. Further developments in this field are in active progress.     

吡唑基镁卤化物/四氢呋喃可充镁电池电解液

将不同配比的吡唑与格氏试剂反应制得的吡唑基镁卤化物/四氢呋喃(THF)溶液用作可充镁电池电解液,采用循环伏安和恒电流充放电测试研究了该电解液的镁沉积-溶出性能和氧化分解电位;并通过X射线衍射(XRD)和扫描电镜(SEM)对沉积物的组分和形貌进行了分析.结果表明,吡唑上的取代基、吡唑与格氏试剂的反应配比对电解液的电化学性能都有影响.1 mol·L-11-甲基吡唑-PhMgCl(1:1摩尔比)/THF反应配制的电解液在不锈钢(SS)集流体的阳极氧化分解电位达到2.4 V(vs Mg/Mg2+),并具有镁沉积-溶出电位低、循环稳定性高、配制方便的特点,有希望应用于实际的可充镁电池体系中.     

吡唑基镁卤化物/四氢呋喃可充镁电池电解液

将不同配比的吡唑与格氏试剂反应制得的吡唑基镁卤化物/四氢呋喃（THF）溶液用作可充镁电池电解液,采用循环伏安和恒电流充放电测试研究了该电解液的镁沉积-溶出性能和氧化分解电位;并通过X射线衍射（XRD）和扫描电镜（SEM）对沉积物的组分和形貌进行了分析. 结果表明,吡唑上的取代基、吡唑与格氏试剂的反应配比对电解液的电化学性能都有影响. 1 mol·L^-1 1-甲基吡唑-PhMgCl（1：1摩尔比）/THF反应配制的电解液在不锈钢（SS）集流体的阳极氧化分解电位达到2.4 V（vs Mg/Mg²⁺）,并具有镁沉积-溶出电位低、循环稳定性高、配制方便的特点,有希望应用于实际的可充镁电池体系中.     

Study of electronic effect of Grignard reagents on their electrochemical behavior

The electrochemical behavior of three electrolyte solutions containing Grignard reagents (RMgBr) with different organic groups were investigated with regard to the potential application in rechargeable magnesium battery. It is found that the electrochemical reversibility of magnesium deposition and dissolution processes and the anodic stability of the Grignard electrolyte can be significantly improved by replacing alkyl group with more stable 4-Fluorophenyl group. In addition, the ionic conductivity of the Grignard electrolyte solution is enhanced by 1.5 times by such a replacement. The test results indicate that 4-Fluorophenyl-MgBr/THF solution could be promising for use in rechargeable magnesium battery systems.     

碳酸酯类电解液中Mg(NO3)2添加剂抑制锂枝晶生长的研究

在锂-硫化聚丙烯腈电池体系中,负极锂枝晶的形成和生长严重恶化了电池充放电性能,并给电池带来了安全隐患。而在更有利于稳定正极硫化聚丙烯腈材料的碳酸酯类电解液中,锂枝晶生长尤为严重。本文通过将硝酸镁添加到碳酸酯类电解液中,研究硝酸根和镁离子对锂金属表面改性的共同作用。实验数据发现,在硝酸根和镁离子共同作用下,锂枝晶生长被有效抑制。当硝酸镁浓度为100 mmol·L^-1时,锂铜半电池的库仑效率明显提高,并显著改善了锂-硫化聚丙烯腈电池的循环性能。300次循环后容量保持率为71%,远高于硝酸锂的61%和无添加剂的50%。     

苯硫酚盐基溶液的可充镁电池电解液

将4-甲基苯硫酚、4-异丙基苯硫酚和4-甲氧基苯硫酚(RSH)分别与格氏试剂C₂H₅MgCl/THF(四氢呋喃)反应制得的苯硫酚氯化镁(RSMgCl)(分别标记为MBMC、IPBMC和MOBMC)/THF和进一步与Lewis 酸AlCl₃反应制得的(RSMgCl)_n-AlCl₃/THF(n=1,1.5,2)苯硫酚盐基溶液用作可充镁电池电解液,采用循环伏安和恒电流充放电测试研究了电解液的镁沉积-溶出性能和氧化分解电位. 结果表明,苯硫酚上的基团种类和RSMgCl与AlCl₃的比例对其电化学性能有影响. 其中,0.5 mol·L^-1(IPBMC)_1.5-AlCl₃/THF 溶液具有最佳的电化学性能,其氧化分解电位适宜(2.4 V(vs Mg/Mg²⁺)),镁沉积-溶出循环效率稳定,过电位低,电导率较高(2.48 mS·cm^-1),与正极材料Mo₆S₈兼容性良好,且具有一定的空气稳定性,配制方便,有希望应用于实际的可充镁电池体系中.     

Boron Clusters as Highly Stable Magnesium‐Battery Electrolytes

Boron clusters are proposed as a new concept for the design of magnesium‐battery electrolytes that are magnesium‐battery‐compatible, highly stable, and noncorrosive. A novel carborane‐based electrolyte incorporating an unprecedented magnesium‐centered complex anion is reported and shown to perform well as a magnesium‐battery electrolyte. This finding opens a new approach towards the design of electrolytes whose likelihood of meeting the challenging design targets for magnesium‐battery electrolytes is very high.     

Magnesium ion conducting, room temperature molten electrolytes

Room temperature, magnesium ion conducting binary molten electrolyte consisting of acetamide and magnesium perchlorate has been prepared and characterized. The molten liquid is very stable and shows high ionic conductivity, of the order of several mS cm⁻¹ at 25 °C with other favourable physicochemical properties. Vibrational spectroscopic studies reveal that the free ion concentration is higher than that of ion pairs and aggregates in the melt. The electrochemical reversibility of magnesium deposition and dissolution is demonstrated using voltammetry and impedance studies. Preliminary studies on rechargeable batteries assembled using γ-MnO₂ and Mg metal as the electrodes together with the molten electrolyte show high discharge capacity.     

The electrodeposition of magnesium using solutions of organomagnesium halides,amidomagnesium halides and magnesium organoborates

The electrochemical behaviour of three groups of electrolyte systems having the ability of electrochemical magnesium deposition, were investigated against the background of galvanotechnical or battery application. Solutions of organomagnesium halides, amidomagnesium halides and magnesium organoborates dissolved in tetrahydrofuran were characterized in terms of conductivity, reversibility of the magnesium deposition process and stability of the electrolytes versus irreversible oxidation. Furthermore the open circuit potential of a magnesium electrode in contact with these electrolytes was measured versus a Ag/Ag⁺ reference electrode. A high reoxidation efficiency was found for magnesium electrodeposited from solutions of organomagnesium halides and amidomagnesium halides. The solutions of magnesium organoborates were superior in terms of electrical conductivity and oxidation stability, the process of magnesium electrodeposition and reoxidation, however turned out to be poor.     

An Efficient Halogen‐Free Electrolyte for Use in Rechargeable Magnesium Batteries

Unlocking the full potential of rechargeable magnesium batteries has been partially hindered by the reliance on chloride‐based complex systems. Despite the high anodic stability of these electrolytes, they are corrosive toward metallic battery components, which reduce their practical electrochemical window. Following on our new design concept involving boron cluster anions, monocarborane CB₁₁H₁₂^? produced the first halogen‐free, simple‐type Mg salt that is compatible with Mg metal and displays an oxidative stability surpassing that of ether solvents. Owing to its inertness and non‐corrosive nature, the Mg(CB₁₁H₁₂)₂/tetraglyme (MMC/G4) electrolyte system permits standardized methods of high‐voltage cathode testing that uses a typical coin cell. This achievement is a turning point in the research and development of Mg electrolytes that has deep implications on realizing practical rechargeable Mg batteries.