锂离子电池锡基合金负极材料研究进展

锡合金负极材料由于具有加工性能好、导电率高、对环境的敏感性没有碳材料明显等优点,未来有希望取代碳负极材料。但由于其首次不可逆容量高。循环性能不好。影响了其商业化的进程。作者对近年来有关于锡合金负极材料的研究进行了分析;重点介绍了锡合金储锂机理,比较了不同合成方法及组成对材料性能的影响。总结了材料存在的问题,并时锡合金负极材料的前景进行了展望。     

锂离子电池锡基负极材料的研究进展

锡基负极材料与碳负极材料相比,具有容量密度高,安全性好等优点,成为动力锂离子电池用新型负极材料研究的热点之一。本文综述了近年来国内外针对锡基材料首次不可逆容量高、循环性能差等问题所进行的改性研究,分别从材料的制备方法、组成结构及电化学性能等方面进行比较分析,并对锡基负极材料的进一步研究、发展应用予以展望。     

Bi/SnO_(x)@C异质结构材料制备及其钠离子电池性能EI北大核心CSCD

锡基氧化物及其合金具有制备简单和理论比容量高等优点,是一种有前途的钠离子电池负极材料。然而,锡基氧化物及其合金在循环过程中会发生颗粒团聚及体积形变,导致电极粉化、容量衰减和倍率性能差等问题。在此,本工作采用氯化钠模板法合成了Bi/SnO_(x)颗粒锚定在超薄碳层上的复合材料(Bi/SnO_(x)@C),构筑了一种均匀的Bi/SnO_(x)@C异质结构。其中,超薄碳层可以有效抑制Bi/SnO_(x)复合颗粒的团聚并增加电极材料比表面积,提供更多活性位点,同时Bi/SnO_(x)也能够贡献更多的比容量。超薄碳层与Bi/SnO_(x)复合颗粒的协同作用可以有效提高电极材料循环稳定性,对于构筑高性能电极材料具有重要意义。     

锂离子电池电极性能的改进

负极材料对于可充电锂电池的容量和提高和循环性能的保证具有重要的意义。通常用于可充电锂电池的负极材料有碳类（如石墨、软碳、硬碳等）、金属氧化物、金属硫化物等。其中，尤以石墨等材料的技术比较成熟，综合性能优良、价廉易得；而其它材料则存在一定问题，尚处于研究阶段。但实际使用与研究表明，可充电锂电池所用的石墨负极材料首次不可逆容量损失较大，首次充放电效率低。这是目前可充电锂电池存在的缺点，影响了其功能的发挥。     

中间相炭微球在锂离子电池负极材料的应用进展

中间相炭微球(MCMB)具有良好锂离子扩散性、导电性和机械稳定性等优势,是目前应用广泛、综合性能优异的锂离子电池负极材料,但较低理论比容量是制约其发展的关键因素。为了获得性能优良的MCMB基锂离子电池负极材料,改性修饰和复合材料已然成为目前研发重点。笔者论述了碳结构、表界面和复合材料等微观结构设计对MCMB负极材料电化学性能的影响。从碳堆积结构类型、有序性、层间距以及球体粒径大小等方面,论述了碳结构微观设计对MCMB电化学性能的影响。发现具有乱层结构的MCMB在充放电过程中内部产生应力较小,且碳结构较稳定,具有优异循环稳定性;内部具有大量微孔或碳层间距较大的MCMB,在充放电过程中可提高锂离子在电极中的迁移速率,并提供更多的储锂空间,一般具有优良的充放电比容量和倍率性能;小粒径MCMB具有较短的锂离子迁移路径和随之增加的比表面积,通常具有较好倍率性能,伴随着可逆比容量和充放电效率的衰减。从表界面碳层改性、包覆和掺杂改性等方面,论述了表界面改性对MCMB电化学性能的影响。表面碳层修饰可增加MCMB与电解液的相容性及其比表面积,提高了与电解液的接触面积及贮锂容量,改善了锂离子电池负极材料的电化学性能;另外,MCMB表面包覆一层无定型碳,可避免其表面与电解液直接接触,减少电化学副反应的产生,提升其可逆比容量。从碳活性物质复合材料、非碳活性物质复合材料等方面,论述了复合材料微观结构设计对MCMB电化学性能的影响。碳活性物质可降低MCMB内部碳层结构的有序性,减少锂离子嵌入过程中的内部应力,提升MCMB循环稳定性。非碳活性物质诱导MCMB生成更加有序的碳层结构,提高MCMB的比表面积,从而改善MCMB表面与电解液分子的接触能力及其嵌锂性能,有利于提升MCMB负极材料可逆比容量、循环性能和倍率性能。MCMB具有高碳层间距和多缺陷位点等结构特征,有利于钠离子自由脱嵌,应用于钠离子电池时具有良好的可逆比容量、循环稳定性和倍率性能。MCMB的不规则定向层状结构经活化等处理具有较高比表面积,可应用于超级电容器电极材料。最后提出在高性能锂离子电池电极材料快速发展的需求下,从微观结构角度设计MCMB纳米复合材料将是MCMB负极材料的研究重点。     

钠离子电池碳基负极材料的研究进展

电极材料的研究开发是钠离子电池技术发展和应用的关键之一,碳基负极材料具有原料丰富、成本低廉、可逆容量较大及倍率性能良好等优点,备受国内外专家、学者的关注。本文系统综述了钠离子电池碳基负极材料的最新研究进展,就石墨类和非石墨类碳基负极材料的分类和掺杂改性研究进行了详细介绍。石墨类材料有石墨和石墨烯,非石墨类材料有软碳和硬碳;元素掺杂改性主要是以N和S为主,并分别阐述了各种碳基负极材料的电化学性能及可能的充放电机理。分析了目前碳基负极材料面临着首次库仑效率较低、电压滞后现象严重、循环稳定性能不佳等问题,未来的发展方向主要是增大碳基负极材料的碳层间距、结构的纳米化以及优化制备工艺,以确保循环稳定性及倍率性能的优异性。     

基于油茶果壳的C/ZnO复合材料制备及其在铅碳电池中的应用

铅碳电池是一种新型的铅酸蓄电池,在一定程度上,铅碳电池可以抑制高倍率部分电荷状态(HRPSoC)下,负极出现的不可逆硫酸盐化现象。但由于碳材料的加入,铅碳电池会出现析氢等问题,另外如何进一步抑制负极不可逆硫酸盐化,仍然是铅碳电池面临的问题。通过溶胶-凝胶法制备油茶果壳C/ZnO复合材料,利用XRD、SEM、BET、EDS、电化学测量技术等手段对复合材料进行表征分析,结果表明,ZnO成功包覆在碳材料表面,由此获得Zn(Ac)₂∶油茶果壳碳材料的最佳质量比为1∶5.69,在该质量比下,油茶果壳结构得到较好的保留,比表面积为152.04 m²/g,添加C/ZnO复合材料的负极材料的比电容为5.25 F/g、电极电阻为0.22498Ω。组装模拟铅碳电池,进行首次充放电、循环寿命测试,质量比为1∶5.69的油茶果壳C/ZnO复合材料相较于物理研磨对照样品材料电化学性能更好,其首次放电容量为177.6 mA·h/g,在250次循环后,容量保持率为64.3%。这表明,在负极材料中加入油茶果壳C/ZnO复合材料,能够有效抑制铅碳电池负极不可逆硫酸盐化和析氢现...     

锂离子电池石墨负极材料的改性研究进展

石墨类碳负极材料作为电化学嵌锂宿主材料的研究一直是锂离子电池负极材料研究的重点。本文简述了石墨作为锂离子电池负极材料的结构,分析了石墨作为负极材料的优缺点,综述了石墨负极材料的改性方法及其研究进展,指出了石墨改性的发展方向。通过改性处理可以提高可逆比容量和首次库仑效率,改善其倍率性能和循环稳定性,有效改善石墨电极的综合电化学性能。     

氮硫共掺杂石墨烯/SnS_2纳米复合材料的制备及储锂性能

锡基负极材料的理论储锂容量高,但循环稳定性和倍率性能差,难以满足实际应用的需要。我们以四氯化锡、二硫化碳、氨水、石墨烯为原料,采用水热-热处理相结合的方法,合成了氮硫共掺杂石墨烯/硫化锡复合材料(SnS_2@N,S-RGO)。该材料中,硫化锡纳米粒子均匀地生长在石墨烯上,增大了其比表面积,提高了其稳定性和导电性。因此,该复合材料的储锂容量高、倍率性能和循环稳定性好,有望用于高性能锂离子电池。     

锂离子电池柔性碳布负极材料的储锂性能研究

将柔性碳布用于锂离子电池负极材料,用循环伏安法及交流阻抗研究了电池电极材料的电化学性能,用充放电实验研究了电池的循环性能和倍率性能。结果表明,锂离子电池负极采用柔性碳布,具有高的锂储存容量,第一次放电比容量为157.48mAh/g,并且在随后各次的容量损失很小,电池循环趋于稳定。     

工艺参数对电沉积锡-钴合金镀层性能的影响

研究了在泡沫镍基体上电沉积锡-钴合金镀层的工艺方法,分析了电沉积工艺参数对锡-钴合金镀层性能的影响,并对工艺进行了优化.研究表明:采用该优化工艺所制得的锡-钴合金能提高锂离子电池的容量、稳定性和循环性能.     

Mechanical stability of Sn-Co alloy anodes for lithium secondary batteries

An electro-co-deposited Sn-Co alloy electrode on a copper foil was prepared to study the structure and electrochemical properties. A micro-island structure of the active material was confirmed to be self-organized during the initial cycle, and such a structural change of the active material was compared with that of other Sn-based electrodes. A key to improve the cyclability in terms of the mechanical stability of the active material is discussed.     

光亮剂对电沉积枪黑色锡-钴合金的影响

研究了不同电沉积锡一钴舍金光亮剂对光亮效果的影响,其中PEI(聚乙烯亚胺)和PEG(聚乙二醇)效果较好.通过XRF极化曲线和循环伏安等方法研究可知:PEI通过辅助配住作用控制钴的质量分数,加速锡电沉积及增强阴极极化得到枪黑色光亮镀层;而PEG通过吸附和加速锡沉积起光亮作用,两者复配,镀层光亮效果更好.     

Sn-based glass–graphite-composite as a high capacity anode for lithium-ion batteries

Sn-based anode has been widely studied because of its high theoretical specific capacity. However, the capacity of Sn-based anode decreases sharply during the cycle, which hinders its application in commercial batteries. In this paper, Sn-based glass was successfully obtained by melt quenching method. Sn-based glass and graphite were combined by the ball milling method as anode materials. The Sn-based glass–graphite-composite anode can still maintain the capacity of 700 mA h g⁻¹ after 500 cycles at 500 mA g⁻¹, which is about 2.7 times that of the Sn glass anode (260 mA h g⁻¹) under the same test conditions. The addition of graphite can effectively inhibit the accumulation of Sn particles in the discharge process of Sn-based glass anode, which improves the capacity of Sn-based glass anode, and the addition of graphite can effectively reduce the resistance of Sn-based glass anode. Therefore, the Sn-based glass–graphite-composite anode has excellent Li⁺ ions storage properties.     

锂离子电池锡钴和锡钴碳负极材料的研究进展

综述了锂离子电池锡钴二元合金和锡钴碳三元复合材料的结构、电化学性能,反应机理及制备方法.改善锡基材料的循环性能主要有3个途径:元素多元化,减小颗粒粒度,无定形化.仅靠上述单一途径很难达到产业化对循环性能的要求,因此多种途径联合运用成为解决循环性能的研究趋势.     

Electrodeposition of Sn-Co alloys from gluconate baths

Electrodeposition of Sn-Co alloys was carried out from baths containing 2–20 g dm^–3 SnSO₄, 4–18 g dm^–3 CoSO₄.7H₂O, C₆H₁₁O₇Na and K₂SO₄ under different conditions of bath composition, pH, current density and temperature on to copper substrates. The influence of these variables on the cathodic potential, cathodic current efficiency and composition of the deposit were studied. The results show that the deposition of Sn-Co alloys from gluconate baths depends greatly on the concentration of tin. At high tin concentrations, tin is the more noble component. At low tin concentrations, tin reduction is strongly suppressed due to the formation of a more stable Sn-gluconate complex species and tin becomes the less noble component. The codeposition of Sn-Co alloy from these baths can be classified as an irregular plating system. The surface morphology of deposits was examined by scanning electron microscopy and crystal structure by X-ray. The results show that the structure of the deposits was controlled by the alloy composition.     

Sn-Co-artificial graphite composite as anode material for rechargeable lithium batteries

Nanosized Sn-Co prepared by ultrasonic-assisted chemical reduction is milled with artificial graphite (AG) to form Sn-Co-AG composite. The as-prepared materials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectrometry and Brunauer-Emmett-Telle (BET) surface area measurement. XRD patterns show that Sn-Co particles are poorly crystallized and artificial graphite has a typical hexagonal graphite structure phase. The diffraction peaks of Sn-Co particles remain the same but some of AG obviously change after milling Sn-Co with AG. BET areas of AG, Sn-Co and Sn-Co-AG are 1.569, 13.187 and 6.754 m² g⁻¹, respectively. SEM images display the as-prepared Sn-Co particles have a size distribution ranging from 20 to 70 nm in diameter. After milling Sn-Co with AG, Sn-Co particles keep similar morphology but there is a perceptible change in AG. Electrochemical tests show that Sn-Co-AG composite possesses much improved electrochemical performance than the state-of-the-art graphite. This composite has great potential as an alternative material for improving the energy density of a lithium ion secondary battery.     

The effect of vacuum evaporation plating on phase structure and electrochemical properties of AB5–5 mass% LaMg3 composite alloy

In this paper, Cu, Al and Ni were plated on the AB₅–5 mass% LaMg₃ composite hydrogen storage alloy using a vacuum evaporation plating method. The phase structure and the electrochemical properties were investigated. The X-ray diffraction (XRD) analysis shows that the phase structure is not changed obviously after the plating Cu, Al and Ni on the composites. The electrochemical tests show that maximum discharge capacity, high rate dischargeability (HRD), dischargeability at low temperature and cyclic stability was improved by vacuum evaporation plating Cu, Al and Ni. Maximum of discharge capacity of the AB₅–5 mass% LaMg₃ composite alloy plating Ni can reach 351 mAh/g, which is 3.5% higher than that of the untreated. HRD at I_d = 1200 mA/g of the composite alloy plating Cu is 45.0% of that at 60 mA/g, which is 20.4% higher than the untreated. Discharge capacity of the composite alloy plating Cu at low temperature 233 K is 205 mAh/g, which is 57.3% of that at 298 K, and it is much higher than 36.8% of the untreated composites. The discharge capacity retention of the composite alloy plating Al after 200 cycles is 7.8% higher than the untreated.     

化学镀镍对LaMgNi3.7Co0.3储氢合金电化学性能的影响

在LaMgNi3.7Co0.3储氢合金粉末表面进行化学镀镍处理。镀覆镍的合金粉末与镍粉混合后涂于泡沫镍上制成电极。当镀液中Ni2+为40 g/L、温度为50°C、镀液pH为8.0、反应时间为30 min时,合金电极在6 mol/L KOH电解液中的最大放电容量和循环稳定性都有显著提高,合金电极的交换电流密度增大,极化电阻降低,其动力学性能增强。     

The study of carbon-based lead foam as positive current collector of lead acid battery

The carbon-based lead foam was produced by electrodepositing a uniform and dense lead coating on lightweight carbon foam in fluoborate system under appropriate conditions. The cyclic voltammetry showed that its electrochemical properties resembled the metallic pure lead. A lead acid battery equipped with the carbon-based lead foam as positive current collector undergone a charge–discharge test. The battery had a high discharge capacity and a good cycling stability, which indicated that the carbon-based lead foam could serve as positive current collector. The three-dimensional net structure of carbon-based lead foam provides larger surface area than traditional lead alloy grids, thus enhances the specific capacity of lead acid battery. The carbon-based lead foam might be a promising substitute for lead alloy grids.