模板-电沉积法制备锡钴碳锂离子电池负极材料

以柠檬酸、EDTA为络合剂,CoCl2、SnCl4为主盐的基础电解液,首先在基础电解液中加入硬碳制备Sn-Co-C复合电极材料.SEM观察表明获得的Sn-Co-C复合电极表面为镶嵌C小颗粒的菜花状结构,C物理夹杂在Sn-Co合金中,硬碳的引入使得电极材料的循环性能得到提高,首次充放电比容量分别为563.8和763.2 mA·h/g,而经过50次循环后充放电比容量分别为400.3和416.2 mA·h/g.然后,在基础电解液中加入甲酸,在聚苯乙烯微球(PS)为模板的辅助下制备孔状结构Sn-Co-C复合材料.获得的材料中Sn、Co、C的原子比分别为36.87%,2.82%,20.61%.充放电测试结果表明,孔状结构的Sn-Co-C电极表现出更好的循环性能,首次充放电比容量分别为821.1和946.6 mA·h/g,循环第50次后充放电比容量为401和457.6 mA·h/g,循环第60次后充放电比容量为349.7和401.5 mA·h/g,放电比容量达到400 mA·h/g以上.     

水热-碳热还原原位合成锂离子电池Sn-Co-C复合负极材料

以纳米二氧化锡、硝酸钴、脲、葡萄糖和十二烷基硫酸钠为原料,通过水热-碳热还原原位制备锂离子电池Sn-Co-C复合负极材料。通过XRD、SEM、EDS和TEM分析表明,原位生成的Sn-Co合金颗粒分布于纳米或微米尺度的碳球和碳纳米棒内部以及微孔碳基体之中。电化学测试表明,在50 m A·g-1电流密度下,Sn-Co-C复合负极材料首次充放电比容量分别为602.9 m Ah·g-1和867.1 m Ah·g-1,循环100次后其充放电比容量仍分别保持在350.4 m Ah·g-1和356.6 m Ah·g-1,平均每次放电容量衰减率仅为5.1%。优异的电化学性能主要归因于Sn-Co合金颗粒处于纳米或微米尺度的碳球和碳纳米棒内部以及微孔碳基体之中可以改善其导电性,并可以缓解锂电池充放电过程中产生的体积变化所导致的活性物质脱落,提高循环性能和寿命。     

多孔泡沫铜支撑锡薄膜阳极材料的制备及性能

以三维多孔泡沫铜为基底,采用化学镀的方法制备锂离子电池薄膜Sn负极材料.利用扫描电镜、X射线衍射分析以及恒电流充放电测试等手段研究不同厚度薄膜Sn电极的形态、结构和电化学行为.结果表明:化学镀工艺制备的Sn电极表面的大量微孔和岛状突起不仅增大电极的表面积,而且显著缓解电极在充放电过程中体积的变化;其中镀层较薄的样品C薄膜Sn电极的初始充电(脱锂)容量为660.6 mA·h/g,经100次循环后,容量保持在299.5 mA·h/g,具有较好的循环性能.     

电沉积法制备Sn-Co-C锂离子电池负极材料

分别采用柠檬酸和乙二胺四乙酸(EDTA)作为络合剂在CoCl2、SnCl4溶液中用电沉积方法制备Sn-Co合金电极,然后在相同条件下在镀液中加入硬碳制备Sn-Co-C复合电极.充放电测试结果显示,EDTA作为络合剂时镀层循环性能明显好于柠檬酸,且比容量也较高.Sn-Co合金电极循环30次比容量保持率达91.6%,加入硬碳的Sn-Co-C复合电极比容量及循环性能较之Sn-Co合金电极都有了较大提高.电子探针结果表明,EDTA作为络合剂的Sn-Co-C镀层中Sn、Co、C原子分数分别为61.8401%,22.3788%,12.5409%.SEM观察Sn-Co-C镀层表面为稳定的球状结构.     

共沉积Co3O4-石墨负极材料及其在锂离子电池中的循环性能

在0.5 mol/L Co(NO3)2溶液中添加石墨粉,在铜箔集流体的表面电化学共沉积前驱体薄膜,然后在245℃真空热处理使之形成Co3O4-石墨粉复合负极材料.研究了共沉积Co3O4-石墨负极材料在锂离子电池中的循环性能.XRD分析和SEM观察表明,该电极材料结构由蜂窝状的Co3O4包覆石墨粉复合而成,Co3O4晶粒尺寸为0.7～2.2 nm.0.5C充放电倍率测试表明,在0.5 mol/L Co(NO3)2电解液中添加5%石墨粉形成的Co3O4-石墨复合材料负极的性能最好,该电极的初始充电比容量为872.7 mA·h/g,第20周循环的充电比容量为732.7mA·h/g,第50周循环的充电比容量为545.2 mA·h/g,比容量保持率分别为83.96%和62.47%;而纯Co3O4电极的初始充电比容量为665.3 mA·h/g,经过20次循环后充电比容量为407.9 mA·h/g,第50周循环的充电比容量为124.5mA·h/g,保持率仅分别为61.31%和18.31%.     

锂离子电池用金属锡电沉积层的储锂性能

以铜箔为基体,采用电沉积法制备锡电沉积层,并将其制成锂离子电池用锡电极。采用扫描电子显微镜、X射线能量分散分析、X射线衍射、循环伏安和恒流充放电等对锡电极的物理性质和电化学性能进行表征。结果表明:调整电沉积时间可以有效地改变锡沉积层的表面形貌;电沉积5min获得的网状多孔结构的锡沉积层具有较大的不可逆容量和较好的电化学循环性能;电沉积较长时间制得的致密颗粒状金属锡电沉积层具有相对较大的可逆储锂容量,但其在电化学循环过程中会出现容量衰退现象;锡颗粒尺寸的降低有利于改进颗粒状金属锡电沉积层的储锂性能;电沉积15min制得的锡沉积层由粒径较小的颗粒组成,经30次充放电循环后其可逆储锂容量为400mA·h/g。     

Electrochemical Behavior of Fe—Based Coatings Containing Amorphous Phase Prepared by Electric Arc Spraying

采用倒相法在Cu箔上制得与Cu箔结合牢固的PAN与石墨多孔复合膜,以其作阴极、纯Sn作阳极进行脉冲电沉积, Sn通过多孔复合膜的微孔沉积在铜箔上,然后在氩气气氛中热处理,得到具有复合结构的Sn基合金电极(碳膜隔离的Cu-Sn合金),用作Li离子电池的负极. SEM和EDS能谱分析以及模拟电池的电化学性能测试结果表明:与通常的在裸Cu箔上直接电沉积Sn并热处理的Sn电极相比,这种具有复合结构的Sn电极热处理后具有更好的循环性能和更高的循环容量,首次放电容量达到538.3 mA·h/g,50次循环后充电(Li离子的脱出)循环容量保持率仍有85.5%.     

电沉积-烧结法制备掺杂碳的Co3 O4锂离子电池负极材料

采用电沉积-烧结法制备了掺杂C的Co3O4锂离子电池负极材料.XRD分析结果表明,电沉积物质是Co(OH)2,经245℃的真空烧结后转变为Co3O4.能谱分析表明,镀液中添加甲醛后,获得的镀层中含有C.SEM观察发现加入甲醛后镀层表面形成的孔间距加大、空隙增多、孔壁变薄.在Li/Co3O4电池充放电过程中,加入甲醛不但使电极的稳定性得到明显改善,而且比容量的值也有所提高.电极性能试验表明加入甲醛后电池的循环寿命得到明显改善.     

锂掺杂对石墨电化学性能的影响

研究了掺杂锂元素对用作锂离子电池负极的石墨材料的结构与性能的影响. XRD及元素分析结果表明 锂以化合物的形式存在于石墨材料中, 由于缺陷结构的增加, 掺杂后石墨材料的BET比表面积略有增大. 电化学测试结果表明 预先掺锂能够有效减少首次充放电过程中的不可逆容量, 使石墨电极的可逆容量增加. 与未掺杂的热处理石墨比较, 可逆嵌锂容量由304.5 mA*h/g增加到312.2 mA*h/g, 首次充放电不可逆容量由66.4 mA*h/g减少到52.9 mA*h/g. 以掺锂改性石墨为负极制作成063448型锂离子电池后, 电池的容量和循环稳定性均得到改善, 以1C倍率充放电时, 放电容量可达845 mA*h, 循环200次后的容量保持率为91.65%.     

钛表面硅复合微弧氧化膜负极的制备及其电化学性能研究

目的 提高锂离子电池TiO2负极的电化学性能.方法 采用微弧氧化技术在钛箔表面制备TiO2膜,再通过磁控溅射技术在TiO2膜上沉积Si/SiO2,制备出一种富含硅元素的微弧氧化复合膜.将该复合膜作为锂离子电池负极,锂片为对电极,组装电池.采用电池测试系统测量电池容量、循环稳定性等性能,通过电化学工作站获得循环伏安曲线、电化学阻抗谱等特性.结果 复合膜的组成为TiO2/SiO2/Si,呈现多孔状形貌.TiO2、SiO2和Si都参与了与锂离子的氧化还原反应,在100μA/cm2的电流密度下,经100圈循环后,复合膜负极的比容量保持在530(mA·h)/g左右,且在1000μA/cm2的大电流密度条件下,充放电后,复合膜负极的比容量能够恢复到初始值的95％,表现出较高的比容量、良好的循环稳定性和倍率性能,复合膜负极性能明显优于以纯TiO2为负极的锂离子电池.结论 在钛箔表面,微弧氧化技术可高效地制备多孔状、无粘结剂的TiO2负极材料,与磁控溅射技术相结合,可进一步制备出高容量的复合膜负极,具有良好的应用前景.     

不同粒径核壳结构聚苯乙烯(PS)-CeO2复合磨料的制备、表征及其化学机械抛光性能

以无皂乳液聚合法制备的不同粒径聚苯乙烯(Ploystrene,PS)微球为内核,以硝酸铈和六亚甲基四胺为原料,采用液相工艺制备具有核壳结构的PS-CeO2复合微球.利用X射线衍射仪(XRD)、透射电子显微镜(TEM)、场发射扫描电镜(FESEM)、傅里叶转换红外光谱仪(FT-IR)和热重分析仪(TGA)等对样品的成分、物相结构、形貌、粒径以及团聚情况进行表征.将所制备的PS-CeO2复合微球作为磨料用于二氧化硅介质层的化学机械抛光,用原子力显微镜(AFM)观察抛光表面的微观形貌,测量表面粗糙度.结果表明:所制备的3种PS微球呈单分散规则球形,粒径分别约为120、170和240 nm;3种PS-CeO2复合微球具有核壳结构,粒径分别约为140、190和260nm,CeO2壳厚约为10 nm.随着PS-CeO2复合磨料粒径的减小,抛光表面粗糙度随之降低,经样品F1抛光后表面在10 μm× 10 μm面积范围内粗糙度的平均值（Ra）及其均方根（Rms）分别为0.372和0.470 nm.     

利用PS模板制备多孔SrFe12O19薄膜的研究

本文以提拉浸渍法使用聚苯乙烯(PS)球模板制备了有序多孔结构的锶铁氧体(SrFe12O19)薄膜。将微乳液聚合法合成的PS球,通过提拉浸渍法有序地组装在硅片基板上形成PS模板;使用溶胶-凝胶法制备SrFe12O19前驱体溶胶,再采用提拉浸渍法使SrFe12O19前驱体溶胶填充PS模板的空隙,在900 ℃保温2 h去除PS球后即制得多孔SrFe12O19薄膜。重点研究了聚乙烯吡咯烷酮(PVP)的含量对PS球微观形貌,浸渍时间对PS模板以及多孔SrFe12O19薄膜微观形貌的影响,并对多孔SrFe12O19薄膜的形成机理进行了讨论,建立了相应的模型。结果表明：添加0.2 g的PVP可得到粒径均匀的PS球,且微球之间空隙明显;将硅片在PS球乳液中浸渍10 s可得到单层有序的PS模板;当PS模板在SrFe12O19前驱体溶胶中浸渍10 s时可制备出孔径约200 nm的蜂窝状多孔结构的纯SrFe12O19相薄膜,其表现出优异的硬磁性能：饱和磁化强度为27.9 emu/g,剩磁为15.5 emu/g,矫顽力为2613.4 Oe。     

Preparation and characterization of Cr-P coatings by electrodeposition from trivalent chromium electrolytes using malonic acid as complex

Cr-P coatings were prepared by electrodeposition from trivalent chromium plating bath using malonic acid as complex. The influences of bath composition on the trivalent chromium electrodeposition process and deposited coating properties were studied. The effects of plating parameters such as current density, bath pH and plating time on structure and morphology of deposited coatings were investigated in detail. XRD, SEM, EDAX and XPS techniques were used to characterize the Cr-P deposited coatings. Results show that the composition, microstructure and surface morphology of the Cr-P coatings depend on bath composition and plating conditions including bath pH, current density, plating time, etc. Results of EDAX and XPS indicate that the deposited coatings contain Cr(s), Cr(III), phosphorus, oxygen and carbon. The optimum bath composition was obtained using malonic acid as complex and the mechanism of Cr-P electrodeposition was analyzed. The optimum plating parameters for good-quality chromium deposited coating are pH 2-3, current density 3-12 dm², temperature 35 °C and Ti/IrO₂ as anode. These results may be of great practical and theoretical significance for further improvement of trivalent chromium plating process.     

乳液模板法制备硅基蜂窝状结构超疏水薄膜及薄膜表征

采用硅溶胶和聚合物乳液混合的方法制得含硅聚合物杂化乳液,然后通过简单的浸渍提拉法在玻璃基片上获得薄膜,薄膜经热处理后,在乙醇中经三甲基氯硅烷修饰,获得了超疏水性能.根据薄膜的表面形貌及其与水的宏观接触角,研究了苯乙烯单体加入量和SiO2溶胶/PS乳液体积比对薄膜疏水性能的影响,并分析了薄膜超疏水的原因.结果表明:热处理...     

Fabrication and thermal degradation behavior of polystyrene nanoparticles coated with smooth polyaniline

Electrically conductive core–shell polyaniline/polystyrene (PAn/PS) nanoparticles were synthesized in the presence of different surfactants. PS core particles were prepared in microemulsion system and further coated with PAn by using in situ polymerization method. The core–shell structure of PAn/PS nanocomposite was determined by scanning electron microscopy (SEM) and FTIR measurement. Differential scanning calorimetry (DSC) and thermo gravimetric analyzer (TGA) were used to investigate the thermal stability and thermal degradation behavior of PS and PAn-coated PS particles. Both DSC and TGA curves revealed that the coating of a thin PAn layer on the surface of PS can drastically increase the thermal stability of PS matrix. TGA isothermal degradation data illustrate that the activation energy of the PAn/PS particle is larger than PS particle.     

低温熔盐电化学制备CoNiFe磁性合金膜

本文从尿素-NaBr-KBr-甲酰胺熔盐体系中,采用恒电位（-0．7V）电沉积得到了CoNiFe合金膜。通过X射线衍射仪（XRD）、X射线能谱仪（EDXS）和振动样品磁强计（VSM）研究热处理对合金膜的晶体结构和磁性的影响。结果表明,热处理不但使合金膜由面心立方（fcc）和六角密堆（hcp）混合晶体组成的薄膜转变成由单一相面心立方（fcc）组成的薄膜,而且有助于改善CoNiFe合金薄膜的软磁性能,使之达到应用水平。     

Poly(2,5-dimethoxyaniline-co-2,5-diaminobenzenesulfonic acid) with cross-linking structure for platinum deposits in methanol oxidation

Cross-linking structural copolymer, poly(2,5-dimethoxyaniline-co-2,5-diaminobenzenesulphonic acid) was synthesized by electrochemical deposition of two monomer, 2,5-dimethoxyaniline, DMA and 2,5-diaminobenzenesulfonic acid, DABSA. The cross-linking structure of copolymer was characterized by scanning electron microscopy, X-ray photoelectron spectroscopy and thermogravimetric techniques. Copolymer with cross-linking structure provides more and deeper nucleation sites for the deposition of platinum (Pt) than homopolymer via electrochemical method, being certified by secondary ion mass spectrometer. Meanwhile, the existence of the SO₃H group in copolymer might also help the electrodeposition of Pt. Copolymer-Pt nanocomposite film demonstrates better activity and stability toward methanol oxidation than homopolymer-Pt.     

UPDHES电泳涂层材料的制备及其防腐性能

目的研究电泳沉积条件及光交联对沉积胶束制备涂层形貌、性能的影响。方法首先通过自由基聚合制备可光交联双亲性丙烯酸酯共聚物(UPDHES),通过全反射红外、氢核磁共振(1H-NMR)对共聚物进行结构表征。然后,将可光交联双亲性丙烯酸酯共聚物在选择性溶剂中自组装形成胶束纳米粒子溶液,利用纳米粒度分析仪、透射电子显微镜(TEM)对胶束粒子的粒径和形貌进行表征。最后,以上述胶束溶液为沉积液,控制不同沉积条件,通过电泳沉积在316L不锈钢表面制备光交联涂层,利用扫描电子显微镜(SEM)、原子力显微镜(AFM)研究了电泳沉积条件及光交联对涂层形貌及性能的影响。同时,通过电化学工作站研究不同条件制备的涂层在1 mol/L HCl中的耐腐蚀性能。结果当沉积电压为5 V、沉积时间为3min时,电泳沉积制备的涂层表面光滑,具有较好的致密性和均一性,此时涂层的自腐蚀电位为-0.36 V,远高于不锈钢(-0.43 V),耐腐蚀性能最优。光交联后,涂层的附着力由2级增加至1级,自腐蚀电位增加至-0.34 V,耐腐蚀性进一步提高。结论电泳沉积胶束制备光交联涂层过程中,沉积时间、沉积电压均存在一最优值,此时制备的涂层结构完整,耐腐蚀性能最好。光交联可进一步提高涂层的耐腐蚀性能。     

A Study on the Effect of Bath Composition on the Internal Stress of a Palladium Electrodeposit

The effects of bath composition on the internal stress of palladium electrodeposits are studied in neutral media with Pd(NH₃)₂Cl₂, K₃C₆H₅O₇, (NH₄)₂C₂O₄ and the additives of the mixture of the synthesized products of nicotinic acid and nicotiamide (NANA), pyridine-3-sulfonic acid(PSA), α-furane formic acid(FF) and cetyl trimethyl ammonium bromide(CTMAB). The results show that the internal stress of electrodeposits is quite changeable at the beginning of electrodeposition later becoming stable gradually. Deposits obtained from pulse electrodeposition have lower stress than that from direct current. After electrodeposition, all the deposits keep in tensile stress which increases with time.     

Self-assembly of polystyrene sphere colloidal crystals by in situ solvent evaporation method

The three-dimensional (3D) ordered colloidal crystals were fabricated on the surface of polystyrene (PS) emulsion through an in situ solvent evaporation, which was controlled by altering both emulsion temperature and environmental pressure. The evaporation rate serves as an important role in intensifying the sphere transfer through solution flux and the capillary force between spheres for assembly, as well as supporting a stable close packing of colloidal crystals. The self-assembly process behaves a multi-nucleus site evolution, and the plane packing undergoes a transformation from square to hexagonal arrangement. The colloidal crystal array achieves an ordered close packing with multi-layer structure at evaporation temperature of 50 °C at normal pressure or proper pressure range of 160–500 mmHg at room temperature. The in situ solvent evaporation by decreasing the environmental pressure at room temperature could reduce disturbing effect of Brownian diffusion for an ordered PS colloidal crystal arrangement. The relationship between layer thickness and in situ evaporation time is a linear trend in time range of 20–75 min.