超声波对泡沫镍抗拉强度和延伸率的影响

针对导电胶法制造泡沫镍存在的抗拉强度、延伸率低，结果不均匀等问题，在制造泡沫镍的浸涂石墨导电胶和电沉积镍的过程中，首次采用超声波发生装置，对比研究了有无超声波的4种情况下制得泡沫镍的抗拉强度、延伸率及三维网络结构。结果表明：超声波增加了石墨导电胶在泡沫基体上浸涂的均匀性；大大提高了镍在石墨导电层上初期沉积和后期沉积的均匀性；增大了Ni的结晶过电位，使Ni的临界晶核半径变小，结晶更加致密；泡沫镍的三维网络结构更加均匀，抗拉强度、延伸率大大提高。在自行设计制造的生产线上，验证了本文的试验结果。     

第二十一讲真空卷绕镀膜

(接2022年第1期88页) 3.5.2 海绵导电化 真空磁控溅射技术是海绵卷导电化处理非常行之有效的方法,也是目前国际上最先进的工艺方法.它可以解决采用化学镀或涂导电胶的方法在海绵镍中产生微量元素污染的问题,提高电池充电次数和使用寿命,同时又可以消除原方法产生的环境污染.其产品的主要特点是泡沫镍杂质少、面电阻小、抗拉...     

磁控溅射法制备石墨烯/Ni复合泡沫及其在超级电容器中的应用

利用磁控溅射方法在泡沫镍(Ni)基底上成功制备出大面积多层石墨烯薄膜,利用拉曼光谱仪、X射线衍射仪、扫描电子显微镜(SEM)和电化学工作站等对其结构和性能进行了表征。结果表明,这些沉积在泡沫Ni骨架上的薄膜具有多层石墨烯结构,进一步以石墨烯/Ni复合泡沫为电极,研究其电化学及能量存储性能,显示了良好的电化学存储性能和充放电速率性能。该石墨烯/Ni复合泡沫材料在电化学能量存储方面具有良好应用前景。     

SiO2薄膜制备的现行方法综述

在导电基体上制作薄膜传感器的过程中,需要在基体与薄膜电极之间沉积一层绝缘膜.二氧化硅薄膜具有良好的绝缘性能,并且稳定性好,膜层牢同,长期使用温度可达1000℃以上,应用十分广泛.通常制备SiO2薄膜的现行方法主要有磁控溅射、离子束溅射、化学气相沉积、热氧化法、凝胶-溶胶法等.本文系统阐述了各种方法的基本原理、特点及适用场合,并对这些方法做了比较.     

制备工艺条件对泡沫镍电阻率的影响

本文探讨了不同的工艺条件对有机多孔体电沉积法所制泡沫镍电阻率的影响。发现两种导电化处理结果相差很大,化学镀镍所得产品的电阻率明显高于浸涂石墨基导电胶所得产品。而去除有机体的热处理,先在空气中短时间预烧再还原烧结,比直接在还原气氛中热解烧结所得产品的电阻率有所降低。     

镍基石墨烯复合材料的研究进展

镍基复合材料在传统颗粒增强体的作用下可以获得力学性能的显著提升,但往往伴随导热、导电等功能性的下降。石墨烯独特的二维结构使其展现出极高的强度与刚度、良好的化学稳定性、优异的导电与导热等性能,自问世以来便成为理想的颗粒增强体,已在金属基复合材料、陶瓷基复合材料、聚合物基复合材料领域大放异彩。因此,石墨烯的添加可以有效提升镍基复合材料的综合性能。石墨烯存在密度低、易团聚、与镍基体的浸润性较差等不足,因此石墨烯制备工艺与稳定性、石墨烯在镍基体中的分散性以及与镍基体的界面结合强度仍然限制着镍基石墨烯复合材料的高性能,如何改进已有制备工艺并不断研发新型工艺仍是科研工作者的研究重点。目前,已有的石墨烯增强镍基复合材料的制备工艺主要有电沉积法、粉末冶金法、分子级混合法、化学气相沉积法等。制备工艺的改进升级提高了石墨烯的分散性以及其与镍基体之间的浸润性,进而综合提升了复合材料的结构性与功能性,这有利于其在电子器件、航天航空、机械化工等领域有较为广泛的应用。本文系统地综述了镍基石墨烯复合材料制备工艺的研究进展,对各种制备工艺的特点进行分析比较,重点介绍了石墨烯对复合材料的硬度、弹性模量、拉伸性能、耐摩擦...     

磁控溅射镍膜催化生长石墨烯及迁移表征

在Si/SiO2衬底上将磁控溅射镍膜作为催化剂,利用化学气相沉积制备了大面积连续的石墨烯薄膜,得到的石墨烯为1～15层.将石墨烯薄膜迁移到玻璃衬底和Si/SiO2衬底上,测量了薄膜的可见光透过率和薄膜电阻,并讨论了石墨烯作为透明导电电极在光电器件上的应用.     

导电胶的研究进展

目的 综述电子封装中用于代替锡铅焊料的导电胶的研究进展,对导电胶未来研究方向进行展望,为导电胶的应用提供参考。方法 从导电胶的组成、导电机理、类型入手,重点介绍导电胶应用时的关键性能要求与测试方法,并总结近几年在提高导电性、稳定性及降低固化温度、成本等方面的研究进展。结果 对导电胶中基体树脂进行改性并选择合适的导电填料(形状、组成),可改善导电胶的固化条件,并提高导电胶的导电性能、黏结性能、耐久性,满足苛刻应用环境下对器件连接高可靠性的要求。结论 相比传统铅锡焊料焊接的方式,导电胶具有绿色环保、连接温度低、分辨率高等特点。因此导电胶适用于电子封装与智能包装领域。目前导电胶的研究方向主要为提高导电性、黏结强度以及黏结稳定性。但是在面对固化时间长、耐湿热性弱、成本较高等缺点时,仍需不断优化组成,以满足实际应用要求。     

纳米填料导电胶研究进展EI北大核心CSCD

本文从理论上分析了纳米填料在电子封装用导电胶中的作用。从纳米填料含量、粒径、形状与维度、表面状态、固化温度与固化时间等方面综述了纳米填料导电胶性能影响因素的国内外研究进展;重点介绍了纳米填料原位生成、纳米填料烧结等导电胶性能改进技术,探讨了存在的主要问题,并指出进一步提高导电导热性能、粘接强度和可靠性,制备应用于柔性封装、喷墨印刷的导电胶以及降低制备成本是未来纳米填料导电胶研究领域的发展方向。     

柔性聚酰亚胺(PI)衬底上ITO薄膜的生长及其透明导电性能影响机制研究

采用直流磁控溅射法在聚酰亚胺(PI)柔性衬底上生长氧化铟锡(ITO)薄膜,采用XP-2探针台阶仪、X射线衍射(XRD)、霍尔测试仪、紫外-可见分光光度计等对ITO薄膜进行结构和光电性能表征.结果表明溅射功率和沉积气压是影响磁控溅射法生长ITO薄膜透明导电性能的主要因素,实验系统研究了溅射功率和沉积气压对ITO薄膜透明导...     

Effect of preparation conditions on relative elongation of nickel foam

Abstract

The effect of preparation conditions on the relative elongation of nickel foams prepared by electrodeposition technology has been studied. The relative elongation is hardly influenced by sintering in NH₃ decomposition atmosphere at 980°C for 40 min, by burning in air at 600°C for 4 min beforehand, or by lowering the sintering temperature to 850°C. With regard to conductive treatment, the relative elongation is significantly higher for chemically plated Ni than for coating by graphite base conductive colloid.     

Synthesis and Magnetic Properties of Ni-Zirconia Composites

A novel method has been developed for the fabrication of composite magnetic films on various conductive substrates. Cathodic electrolytic deposition was used as the technique to obtain thin films from solutions of nickel and zirconium salts. The hydroxide deposits were converted to Ni-ZrO₂composites after sintering in reducing conditions. Deposit yield was studied in the constant current deposition mode. Deposits were evaluated using X-ray analysis and magnetic measurements. Results of dc and ac measurements performed in different magnetic fields, temperatures, and frequencies demonstrated the magnetic properties of the composites.     

The effect of temperature on the growth of carbon nanotubes on copper foil using a nickel thin film as catalyst

Growth of carbon nanotubes (CNTs) on bulk copper foil substrates has been achieved by sputtering a nickel thin film on Cu substrates followed by thermal chemical vapor deposition. The characteristics of the nanotubes are strongly dependent on the Ni film thickness and reaction temperature. Specifically, a correlation between the thin film nickel catalyst thickness and the CNT diameter was found. Two hydrocarbon sources investigated were methane and acetylene to determine the best conditions for growth of CNTs on copper. These results demonstrate the effectiveness of this simple method of directly integrating CNTs with highly conductive substrates for use in applications where a conductive CNT network is desirable.     

氢氧化镍电极导电剂的研究

研究了镍粉，镍粉和石墨的混合物，石墨以及石墨和乙炔墨的混合物分别作为导电剂以机械混合的方式添加到电极活性物质中对氢氧化镍电极性能的影响，并用循环伏安法和交流阻抗法分析了实验结果。结果表明：在这四种导电剂中，镍粉作导电剂时氢氧化镍电极的性能最好，其次是以石墨或镍粉和石墨的混合物作导电剂的氧化镍电极，当石墨和乙炔黑的混合物作导电剂时氢氧化镍电极的性能最差。这是因为当镍作导电剂时氢氧化镍电极的电化学反应电阻最小，质子扩散最容易，电要的可逆性最好，且氧气析出最困难，而当石墨和乙黑和混合物作导电剂时氢氧化镍电极的电化学反应电阻最大，质子扩菜最困难，电极充电过程和析氧过程几乎同时进行，因而充电效率最低，活性物质的利用率最小，电极性能最差。     

Relationship between tensile strength and preparation conditions for nickel foam

Abstract

The relationship between preparation conditions and tensile strength has been investigated for a nickel foam produced by electrodeposition on an organic foam. After sintering in a NH₃ decomposition atmosphere at 980°C for 40 min, the results show that the tensile strength is hardly influenced by burning in air at 600°C for 4 min beforehand, or by lowering the sintering temperature to 850°C. During conductive treatment of the organic matrix it was found that coating with graphite base conductive colloid or chemically plating with Ni–P alloy (～5 wt-%P) brought the same tensile strength for the eventual product.     

Binder‐Free and Carbon‐Free 3D Porous Air Electrode for Li‐O2 Batteries with High Efficiency,High Capacity,and Long Life

Pt‐Gd alloy polycrystalline thin film is deposited on 3D nickel foam by pulsed laser deposition method serving as a whole binder/carbon‐free air electrode, showing great catalytic activity enhancement as an efficient bifunctional catalyst for the oxygen reduction and evolution reactions in lithium oxygen batteries. The porous structure can facilitate rapid O₂ and electrolyte diffusion, as well as forming a continuous conductive network throughout the whole energy conversion process. It shows a favorable cycle performance in the full discharge/charge model, owing to the high catalytic activity of the Pt‐Gd alloy composite and 3D porous nickel foam structure. Specially, excellent cycling performance under capacity limited mode is also demonstrated, in which the terminal discharge voltage is higher than 2.5 V and the terminal charge voltage is lower than 3.7 V after 100 cycles at a current density of 0.1 mA cm^?2. Therefore, this electrocatalyst is a promising bifunctional electrocatalyst for lithium oxygen batteries and this depositing high‐efficient electrocatalyst on porous substrate with polycrystalline thin film by pulsed laser deposition is also a promising technique in the future lithium oxygen batteries research.     

The Lightweight Nickel Fiber Electrode for Nickel-Based Battery Systems

Development of a high specific energy battery is one of the objectives of the lightweight nickel-hydrogen (Ni-H₂) program at the NASA Lewis Research center. The approach has been to improve the nickel electrode by continuing combined in house and contract efforts to develop a more efficient and lighter weight electrode for the nickel-hydrogen cell. Small fiber diameter nickel plaques are used as conductive supports for the nickel hydrogen active material. These plaques have an advantage of increased surface area available for the deposition of active material. Initial tests include activation and capacity measurements at different discharge rates followed by life cycling.     

Enhancement of electrical conductivity and emission stability of oxide cathodes using Ni addition

An investigation has been carried out into the use of conductive phase additions to enhance the conductivity and emission behavior of the oxide cathode coating as used in CRTs. Electrical and emission characteristics have been studied for various additions of filamentary nickel (Ni) added to the sprayed strontium-barium carbonate precursors prior to spray deposition, followed by conventional thermal conversion and activation processes in vacuum. The conductivity and the electronic activation energy have been studied as a function of temperature in the range 300 to 1250 K, during conversion and activation processes allowing the conduction behavior to be compared to conventional materials. The conduction behavior has been found to change as a function of heat-treatment temperature as the conduction paths develop and subsequently evolve in the microstructure of the resultant composite coating during conversion, activation and subsequent aging/service life conditions, with metallic-dominated conduction at temperatures below 850 K and pore conduction mechanisms dominating at higher temperatures. The emission characteristics immediately after conversion are impaired by the Ni addition, however, the long-term emission characteristics show improvement with the conductive phase.     

聚苯胺-石墨烯/聚酰亚胺复合导电纱的制备及其超电容特性

为了提高石墨烯/聚酰亚胺(rGO/PI)复合纱线电极的电化学性能,采用电化学聚合法在rGO/PI复合纱线表面沉积聚苯胺(PANI)颗粒,研究了沉积时间对PANI-rGO/PI复合导电纱的形貌及增重的影响。结果表明, PANI在rGO/PI复合纱线表面均匀沉积,且沉积量随着沉积时间的增加而增大。采用循环伏安法(CV)、恒流充放电法(GCD)研究了PANI-rGO/PI复合导电纱线的电化学行为。结果表明, PANI沉积时间对纱线电极的循环伏安特性、恒流充放电曲线等有很大的影响,当PANI沉积时间为900 s时,所得PANI-rGO/PI复合纱线电极的循环伏安特性和恒流充放电性能表现均最优,比电容为81.22 F·cm^-3,而rGO/PI纱线电极仅为16.4 F·cm^-3。以最优工艺制得的PANI-rGO/PI复合导电纱作为电极组装了纤维状超级电容器,采用交流阻抗谱法(EIS)、 CV及GCD对器件进行电化学性能表征。结果表明,该器件体积比电容可达41.73 F·cm^-3,在充放电3 000次后比电容依然能够维持在85%左右,所得纤维状超级电容器经过串联可成功驱动LED灯。