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1.
张凯  白红美  程方益  陈军 《应用化学》2011,28(8):918-923
采用真空蒸镀法在铜片基底上沉积锡薄膜作为锂离子电池负极材料,对所制备的锡薄膜采用扫描电子显微镜、X射线衍射表征,研究了其表面形貌和组成。 将制备的薄膜在手套箱中组装成CR2032型钮扣式电池,进行电化学测试,研究其电化学性能。 实验结果表明,在相同蒸发时间和基底温度的条件下,随着蒸发功率的增加,沉积的锡颗粒逐渐增大,相应的电化学性能降低。 以蒸发功率200 W、基底温度150 ℃制得的样品粒径为100~200 nm,含有Cu6Sn5合金相,以0.2C倍率充放电循环20周后放电容量达527 mA·h/g。  相似文献   

2.
锂离子电池薄膜锡负极材料的制备及容量衰减机理研究   总被引:1,自引:0,他引:1  
以电镀的方法在铜基底上沉积薄膜锡作为锂离子电池负极材料. 运用X射线衍射、扫描电镜、电化学循环伏安、电化学充放电和交流阻抗等多种方法对其结构和性能进行表征和研究. 结果表明所制备的薄膜锡电极主要为四方晶系结构, 其初始放电(嵌锂)容量为709 mAh•g-1, 充电(脱锂)容量为561 mAh•g-1. 电化学循环伏安研究发现在嵌/脱锂过程中薄膜锡经历了多种相变过程. 电化学阻抗谱结果说明, 首次嵌锂过程中当电极电位达到1.2 V在电极表面形成SEI膜, 而当电极电位低于0.4 V表面SEI膜出现破裂, 归因于体积膨胀所致. SEM研究表明30次充放电循环后薄膜锡负极出现龟裂现象.  相似文献   

3.
采用磁控溅射共溅法,在铜箔和泡沫铜基底上分别制备了平面和三维网状结构的Sn-Al/Cu复合薄膜.表征了其结构,并研究了其作为锂离子电池负极材料的电化学性能.结果表明,三维网状结构的电化学性能明显优于平面复合薄膜,表现出很好的循环性能和倍率性能:以600 mA/g电流密度充放电,三维网状结构的复合薄膜有较好的容量保持率,循环50周后容量保持在410 mA·h/g;以2000 mA/g电流密度充放电,再以500 mA/g电流密度进行充放电,三维网状结构的复合薄膜仍有464 mA·h/g的放电容量.三维网状结构的Sn-Al复合薄膜能抑制充放电时带来的体积膨胀,较大的表面积和粗糙表面可以使其与锂充分反应,改善其电化学性能.  相似文献   

4.
以三维多孔泡沫铜为基底, 通过直接电沉积的方法制备锂离子电池Cu6Sn5合金负极材料. 发现合金表面大量的微孔和“小岛”不仅增大电极的表面积, 而且显著缓解充放电过程中的体积变化. 测得三维多孔Cu6Sn5合金的初始放电(嵌锂)容量为620 mAh·g-1, 充电(脱锂)容量为560 mAh·g-1, 库仑效率达到90.3%, 具有较好的循环性能. 扫描电子显微镜(SEM)结果显示, 在泡沫铜基底上制备的Cu6Sn5合金电极具有比通常的铜片基底更好的结构稳定性, 经过50 周充放电循环后无明显的脱落现象.  相似文献   

5.
为了克服脱嵌锂过程中体积变化引起的机械疲劳导致使用纯锡作为锂离子电池负极时锡的循环性能很差这一问题, 通过氧化铝(AAO)模板辅助生长方法制备了锡纳米棒电极. 用扫描电子显微镜, X射线衍射分析, 循环伏安和恒流充放电测试对锡纳米棒电极的结构和电化学性能进行了初步表征. 扫描电子显微镜观察显示, 铜集流体表面均匀分布着锡纳米棒, 锡纳米棒的平均直径约250 nm. 电化学测试结果表明, 锡纳米棒电极比平面薄膜电极具有更好的容量保持率和倍率性能. 在C/10充放电倍率条件下, 第10次循环的容量仍达到第一次循环的80%, 即使在1C倍率下, 容量仍高于540 mAh·g-1.  相似文献   

6.
以金属氯化物为金属源,硫脲为硫源,聚乙二醇和乙二醇为混合溶剂,采用溶剂热法一步合成了球形的铜锌锡硫纳米颗粒.利用X射线衍射仪(XRD),扫描电子显微镜(SEM)和透射电子显微镜(TEM)分析了铜锌锡硫纳米颗粒的物相、结构、形貌;利用电池测试系统对以铜锌锡硫纳米颗粒为锂离子电池负极材料组装的锂离子电池的电化学性能进行了测试.结果表明:所得到的产物为具有锌黄锡矿结构的纯相铜锌锡硫,颗粒直径在300~500nm.铜锌锡硫纳米颗粒作为锂离子电池的负极材料具有较好的稳定性,有望在锂离子电池研究和应用中得到推广.  相似文献   

7.
Sn-Sb合金的氢电弧等离子体法制备及其电化学性能   总被引:5,自引:0,他引:5  
采用氢电弧等离子体方法成功地合成了锡锑合金纳米颗粒, 通过TEM、XRD、恒电流充放电测试等手段研究了其形态、结构及电化学行为. 结果表明: 锡锑合金纳米颗粒为球形形貌, 颗粒平均直径为138 nm, 由Sn和SnSb两相组成;经电化学性能测试, 该锡锑纳米颗粒首次嵌锂容量高达930 mAh•g−1, 可逆容量为701 mAh•g−1, 20次循环后容量仍为566 mAh•g−1, 容量保持率为81%. 用氢电弧等离子体方法制备的Sn-Sb合金纳米材料是有希望的锂离子电池负极材料.  相似文献   

8.
采用新兴的湿化学方法合成了锡氧化物基粉末材料。用X-射线衍射、扫描电镜和电化学方法对材料的微观结构、形貌和电化学性能进行了详细的研究。结果表明,经400 ℃热处理4 h的锡氧化物基材料的颗粒大小均匀,平均粒径约为200 nm。这种材料的可逆充电容量超过570 mAh·g-1,30次循环后平均每次循环的容量衰减只有0.15%。良好的电化学性能表明锡氧化物基材料有望作为新一代锂离子电池的负极材料。  相似文献   

9.
采用射频磁控溅射法,在Ar气-H2S混合气氛中,以MoS2靶材为原料,在泡沫铜基底上制备了MoS2薄膜。利用X射线衍射(XRD)、Raman光谱、扫描电子显微镜(SEM)、能量弥散X射线谱(EDS)等手段对样品的结构、形貌和成分进行了表征,并探讨了靶功率和基底温度对MoS2薄膜的结构及形貌的影响。结果表明,靶功率的增加可以提高薄膜结晶度,但功率过高会造成薄膜的龟裂;基底温度升高会使MoS2薄膜结晶度明显提高,且形成蠕虫状形貌。靶功率为80 W,基底温度为300℃时,可以制备得到具有较高结晶度的蠕虫状MoS2薄膜。对其进行充放电测试表明,在100 mA·g-1的电流密度下,其首次放电比容量为980 mAh·g-1,经过40周循环,容量可保持为约920 mAh·g-1,容量保持率达到93.9%。  相似文献   

10.
应用射频磁控溅射技术在硅基底上制备氧化锡薄膜,着重研究溅射功率对薄膜结构和电化学性能的影响.XRD,SEM分析及恒电流充放电测试表明,随着溅射功率的增大,薄膜的结晶程度提高;生长速率和晶粒尺寸增大;电池的贮锂容量减少,且首圈不可逆容量损失增大.溅射功率对薄膜的电化学性能有较大的影响.  相似文献   

11.
Porous Si-Al films were fabricated by magnetron sputtering (co-sputtering) using three different copper substrates as current collectors, respectively. The morphology, compositions, structure, and crystallinity of the porous Si-Al films anodes were examined by using SEM, EDX, TEM, XRD, and Raman spectroscopy. The electrochemical properties of the porous Si-Al films anodes were evaluated by galvanostatic cycling. The Si-Al film deposited on copper foam showed higher insertion/extraction capacity, capacity retention, and longer cycle life in comparison to the Si-Al films deposited on expanded copper mesh and even copper mesh grid, which could be attributed to its unique three-dimensional macroporous structure. The three-dimensional macroporous structure could offer larger materials/electrolyte contact area, a much better adhesion, lower electrical resistance (i.e., well conductive), and stress-alleviated environment to partly accommodate volume expansion that leads to exfoliation during cycling.  相似文献   

12.
采用电化学恒电位沉积方法在ITO导电玻璃上和在ZnO薄膜上沉积氧化亚铜(Cu2O),并通过X射线衍射(XRD)和扫描电镜(SEM)对晶体的微观结构和表面形貌进行了分析.在ZnO基底上沉积得到了纳米级的Cu2O粒子并且具有明显择优取向,而在ITO导电玻璃上仅得到粒径为2—5μm的Cu2O粒子,没有明显的择优取向.对薄膜的生长机理进行了讨论.  相似文献   

13.
Thin films were prepared on substrates, cleavage surface of KCl single crystal, and metallic copper, by reaction of 1,2,4,5-tetracyanobenzene with the substrate at various temperatures. The films were characterized by elemental analysis, IR, and UV/VIS spectroscopies. The films were observed by scanning electron microscopy. The films produced on copper at temperatures between 300 and 400°C consisted of copper octacyanophthalocyanine and its polymer with ladder structure. The ratio of polymer to monomer increased with elevating the reaction temperature. The films were composed of ribbon-like crystals. The film produced on copper above 450°C was composed of an amorphous and continuous layer of polymeric copper phthalocyanine. The film produced on KCl at temperatures between 250 and 350°C consisted of potassium octacyanophthalocyanine and its polymer with ladder structure. The film produced on KCl above 450°C was polymeric potassium phthalocyanine. Those films contained more metal content than that required stoichiometrical.  相似文献   

14.
采用氢气泡动态模板电沉积法制备了三维多孔Au掺杂的Pd合金泡沫膜。采用场发射扫描电子显微镜(SEM)、能量分散X射线光谱仪(EDX)、X射线衍射(XRD)和X射线光电子能谱(XPS)对三维多孔PdAu合金泡沫膜的形貌和结构特征进行了表征。由于特殊的多孔结构和电子效应,Au掺杂的PdAu合金泡沫膜与单种多孔Pd膜相比,在碱性介质中对乙醇的电氧化具有高电催化活性。  相似文献   

15.
A set of anatase titanium dioxide (TiO2) films coated on foam nickel that modified by Al2O3 films as transition layer (indicated as TiO2/Al2O3 films) were synthesized via sol-gel route. The bulk and surface properties of the TiO2/Al2O3 films were characterized by thermal gravimetric and differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), and BET. The photocatalytic activities of TiO2/Al2O3 films were investigated based on the degradation of gaseous acetaldehyde under ultraviolet (UV) irradiation. The foam nickel is a promising substrate material in practical applications because of its excellent hydrodynamic properties for gas passing. The TiO2/Al2O3 composite films showed much higher photocatalytic activity and stability for degradation of gaseous acetaldehyde than the onefold TiO2 films. The significant enhancement in photocatalytic activity and stability can be ascribed to the coating of Al2O3 transition layer, which concentrates the target substances around TiO2 particles and increases the specific surface area (SSA) of the substrate (the SSAs of bare foam nickel and Al2O3 modified foam nickel are 0.12 and 113.7 m2/g, respectively) to provide more sites for TiO2 loading.  相似文献   

16.
Copper‐doped iron sulfide (CuxFe1?xS, x = 0.010–0.180) thin films were deposited using a single‐source precursor, Cu(LH)2Cl2 (LH = monoacetylferrocene thiosemicarbazone), by aerosol‐assisted chemical vapor deposition technique. The Cu‐doped FeS thin films were deposited at different substrate temperatures, i.e. 250, 300, 350, 400 and 450 °C. The deposited thin films were characterized by X‐ray diffraction (XRD) patterns, Raman spectra, scanning electron microscopy, energy dispersive X‐ray analysis (EDX) and atomic force microscopy. XRD studies of Cu‐doped FeS thin films at all the temperatures revealed formation of single‐phase FeS structure. With increasing substrate temperature from 250 to 450 °C, there was change in morphology from wafer‐like to cylindrical plate‐like. EDX analysis showed that the doping percentage of copper increased as the substrate temperature increased from 250 to 450 °C. Raman data supports the doping of copper in FeS films. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

17.
The electrodeposition of thin selenium (Se) films from 1-ethyl-3-methyl-imidazolium trifluromethylsulfonate at room and elevated temperatures on gold and on copper substrates was studied under open-air conditions. The effect of bath temperature on the composition and structure of the deposited films was examined using cyclic voltammetry, chemical analysis and X-ray diffraction analysis. The obtained results showed that on gold substrate and at room temperature, a reddish Se film grows mainly in amorphous, monoclinic, rhombohedral and hexagonal structure, while at temperatures ≥90 °C, a grayish film of hexagonal and rhombohedral structure is deposited. Photoelectron spectroscopy shows that both films consist of pure Se with only slight surface contaminations by remnants from the electrodeposition. Due to the differences in phase structure and the presence of the monoclinic phase, the reddish films showed higher light absorbance. The band gap of the reddish film is close to that of pure amorphous Se reported in literature. Deposition on copper substrate leads to formation of CuSe and CuSe2 at room temperature and at 70 °C, respectively.  相似文献   

18.
Flexible thin films of metal–carbon nanotube (CNT) with densely populated CNT morphology were fabricated by electrodeposition from an optimized copper bath. The substrate used for the present work is polyethylene film that was pre-deposited with electroless copper as a seed layer before CNT deposition. Optimum concentration of CNT was incorporated into copper bath and the electrodeposition was done at quiescent and agitation conditions. The bonding between the seed layer and the electrodeposited copper was good as revealed from adhesion test. Electrical as well as physical-mechanical property of the film was improved by CNT incorporation within the metal matrix. The topography and the texture of the metal–CNT deposit showed a well-refined structure as per scanning electron microscope (SEM), field emission scanning electron microscope (FE-SEM), and scanning probe microscope (SPM) analysis. The stability of the film was tested by cyclic voltammetric and stripping analysis under various applied conditions. Raman spectra and Fourier transfer infrared spectroscopic (FT-IR) analysis revealed the presence of CNT and the functionality of CNT within the copper matrix. Transmission electron microscope (TEM) analysis showed nucleation of copper on the surface of CNT walls.  相似文献   

19.
The drainage and stability of DMPG (l-α-phosphatidyl-dl-glycerol dimyristoyl) foams were studied by a microconductivity method under conditions where three different foam film types could be formed—thin foam films (TFF), common black foam films (CBF), and Newton black foam films (NBF). Foaming properties were investigated at 20 and 28°C where DMPG is in the gel and liquid-crystalline states. Higher conductivity signals were observed at the higher temperature where DMPG was in the liquid-crystalline state, which is indicative of wetter or more stable foams under these conditions. This effect was observed independent of foam film type. However, for a given phase state, the type of foam films formed significantly influenced the stability and rate of drainage of the foam. Indeed, the water content of the foams, obtained under conditions for formation of different foam films, is ranked in the order TFF > CBF > NBF. When the temperature was increased to 28°C (i.e., in the liquid-crystalline state), CBF and NBF showed a slight decrease in film thickness and an increase in film lifetime and surface molecular diffusion coefficient in the adsorbed layer. It is likely that the fluidity of the interfacial layer is an important factor contributing to DMPG foam stabilization.  相似文献   

20.
The development of lithium-ion batteries with simplified assembling steps and fast charge capability is crucial for current battery applications. In this study, we propose a simple in-situ strategy for the construction of high-dispersive cobalt oxide (CoO) nanoneedle arrays, which grow vertically on a copper foam substrate. It is demonstrated that this nanoneedle CoO electrodes provide abundant electrochemical surface area. The resulting CoO arrays directly act as binder-free anodes in lithium-ion batteries with the copper foam functioning as the current collector. The highly-dispersed feature of the nanoneedle arrays enhances the effectiveness of active materials, leading to outstanding rate capability and superior long-term cycling stability. These impressive electrochemical properties are attributed to the highly-dispersed self-standing nanoarrays, the advantages of binder-free constituent, and the high exposed surface area of the copper foam substrate compared to copper foil, which enrich active surface area and facilitate charge transfer. The proposed approach to prepare binder-free lithium-ion battery anodes streamlines the electrode fabrication steps and holds significant promise for the future development of the battery industry.  相似文献   

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