贮氢电极合金的发展（一）

在简要介绍有关贮氢合金及名符其镍-氢化物电池概念的基础上,结合最新发展,对各种贮氢电极合金进行了概述,并概要叙述了各种提高贮氢电极合金电化学性能的工艺方法。     

稀土-镁-镍基贮氢电极合金的研究进展

具有超结构特征的稀土-镁-镍基贮氢合金作为新一代金属氢化物/镍(MH/Ni)电池负极材料,因其高的放电容量和好的倍率放电性能,是目前贮氢电极合金发展的重点材料之一。本文从材料相结构、贮氢特性和电化学性能之间的关系出发,综述了近年来国内外稀土-镁-镍基AB3型、A2B7型和A5B19型贮氢电极合金的研究进展,为开发兼具高容量和长寿命的新型稀土系贮氢电极合金提供有价值的参考。     

硼对贮氢合金性能的影响

硼是贮氢合金中很有发展前景的一种元素，将硼及其化合物加入金属氢化物-镍电池的合金电极材料中，可有效改善贮氢合金电极的性能。本文主要评述了硼的添加对贮氢合金力学性能、热力学性能和动力学性能的影响。控制硼的含量对改善MH-Ni电池性能有极其重要的意义。     

碱性蓄电池用贮氢合金

碱性蓄电池用贮氢合金作为各种电力和电子机器的电源，广泛使用碱性蓄电池，且以镍－镉电池应用最多。特别是近年来开发的具有高能密度的无公害新型镍－氢化物电池受到了普遍重视。作为这种镍－氢电池的负电极材料，多用ＬａＮｉ５、ＬａＮｉ２Ｃｏ３、ＬａＭｎ０．５等贮...     

新型绿色电池——金属氢化物／镍电池

金属氢化物—镍电池是一种近年来得到迅速发展的高新技术产品。 与用途最广泛的镉—镍电池相比,金属氢化物—镍电池具有比能量高、无记忆效应、不污染环境、耐过充过放电等优良性能,故被誉为绿色电池。 金属氢化物—镍电池是以贮氢金属材料M作为一个电极,以氢氧化亚镍作为另一个电极,通常采用氢氧化钾水溶液作电解液的一种碱性可充电电池。在充电时,以M作阴极,此时,阴极表面由于水的电化学还原,生成吸附氢原子。吸附氢原子扩散进入阴极,并与贮氢金属材料反应,生成金属氢化物MH_x。在放电时,金属氢化物能释放出所吸收的氢原子,并使其氧化成水,电极反应可表示为:     

表面包覆镍处理La0.67Mg0.33Ni2.5Co0.5贮氢合金电极的电化学性能

研究了表面包覆Ni-P对PuNi3型贮氢合金La0.67Mg0.33Ni2.5Co0.5电极的电化学性能的影响.结果表明:包覆镍处理改善了贮氢合金电极的循环稳定性.线性极化扫描和电化学阻抗谱等分析结果表明,包覆后合金电极的极限电流密度(I1),交换电流密度(I0)以及电化学阻抗均有较好的改善,说明电荷转移和氢的扩散能力得到提高.经25次电化学循环后的电极合金金相观察和分析表明,包覆Ni-P处理没有有效抑制其粉化,这与该类型贮氢合金电化学吸氢时氢化物膨胀较大有关.     

日本－公司在镍－氢蓄电池生产中采用混合稀土贮氢合金

日本－公司在镍－氢蓄电池生产中采用混合稀土贮氢合金日本，夕ｔ。ｖ公司在其生产据点大贩事业所投资１０亿日元，引进了镍一氢蓄电池新型生产设备，作为电池的电极材料采用混合稀土系贮氢合金取代了过去一直使用的Ｌａｖｅｓ相系贮氢合金，并计划在１９９６年春季达到月...     

贮氢合金专利

镍-金属氢化物二次电池用新型贮氢合金及其制备和退火处理方法;一种纳米晶多相混合稀土-镁系贮氢合金及其制备方法     

涂铜的Ti—Zr—V—Mn—Ni金属氢化物电极及其退化行为

作为镍／金属氢化物（Ni/MH）电池的负电极材料，人们在最近几年里广泛地研究了钛基金属氢化物合金，因为它们的贮氨能力比混合稀土（Mm）基金属氢化物的贮氨能力更高一些；但是，这类合金的贮氢能力衰减得很快．韩国学者对退化机制和延长据环寿命的研究都集中在铜基和混合稀土基金属氢化物合金电极上．正如大家所知．这些电极的能力退化原因是合金氧化分解成为La(OH)3和Ni通过往电极表面上涂覆银黑或者用钢股封闭电极都能够解诀这个问题．T．Sakai等人指出，饲涂覆LaNi4.7Al0.3；合金电极的循环寿命之所以比较长，是因为银发挥了氧阻…     

高性能AB5型贮氢合金的成分设计

贮氢合金是MH-Ni电池技术的核心，则其化学成分是决定贮氢合金性能的主要因素，在分析MH-Ni电池对负极材料的性能要求及电极失效机理的基础上，详细讨论了AB5型贮氢合金的主要电化学性能与各种合金元素之间的关系，提出了高性能AB5型贮氢合金成分设计的总体思路和应考虑的各种因素。     

Effects of sintering on composite metal hydride alloy of Mg2Ni and TiNi synthesized by mechanical alloying

As-milled composite metal hydrides composed of Mg₂Ni and TiNi phases were cold-pressed under a pressure of 490 MPa and sintered for 1 h at 5×10⁻⁶ Torr and 300 °C. Electrochemical characteristics of the sintered composite metal hydride electrode were investigated. The maximum discharge capacity of the sintered composite alloy electrode was 125 mAh/g at a discharge current density of 100 mA/g. This value was similar to that of the as-milled one before sintering. However, the sintered electrode retained 80% of the maximum discharge capacity after 150 cycles, while the as-milled electrode retained only 55%. This is because after the sintering process an interface between Mg₂Ni and TiNi plays a role similar to a diffusion layer of hydrogen. In the sintered composite electrode, when a discharging step proceeds, hydrogen absorbed in a Mg₂Ni particle can move into a TiNi phase through the bonded-interface between Mg₂Ni and TiNi, then discharges at the interface between TiNi and the electrolyte. Also, the electrochemical impedance spectroscopy (EIS) tests showed that the composite alloy electrodes had a lower charge-transfer resistance and a higher hydrogen diffusion coefficient than those in single-phase Mg₂Ni. This indicates that TiNi particles in the composite are the active sites for redox reaction of hydrogen and the pathway for the diffusion of hydrogen     

泡沫铜板与铜粉复合烧结多孔材料的制备

介绍了泡沫铜与铜粉的复合多孔材料松装烧结成形工艺;分别采用SEM观察其几何结构特征和称重法,分析了复合多孔材料的收缩率及孔隙率。结果表明,该材料具有大比表面积、高孔隙率特征;采用与纯铜粉烧结类比的方法,探讨了烧结温度、保温时间及铜粉粒径对复合多孔材料的收缩率和孔隙率的影响。结果显示,相比于铜粉烧结多孔材料,泡沫金属与铜粉烧结复合多孔材料具有更小的收缩率及更大的孔隙率。     

小型圆热管烧结吸液芯的设计与制造

小型金属粉末烧结吸液芯圆热管（简称烧结热管）是一种提高高热流密度电子元器件散热性的高热导率元件,而烧结工艺是决定烧结热管质量的关键。根据烧结热管传热特性优化热管吸液芯的结构及工艺,提出制造热管烧结吸液芯的四阶段固相烧结工艺,讨论烧结工艺参数：烧结温度、烧结时间、烧结气氛和烧结位置。结果表明：当烧结吸液芯厚度为0.45 mm,烧结时间为3 h时,159μm铜粉的烧结吸液芯合理的烧结温度是950℃,81μm和38μm铜粉的烧结吸液芯合理的烧结温度为900℃。当铜粉粒径为159μm,烧结温度为950℃时,0.45和0.6 mm吸液芯厚度合理的烧结时间为3 h,而0.75 mm吸液芯厚度合理的烧结时间为1 h。在烧结过程中H2与CuO还原反应能够在铜粉表面形成龟裂纹,而龟裂纹可作为二次结构。水平位置烧结能有效地避免烧结吸液芯与铜管内壁之间产生间隙。     

Investigating the recycling of nickel hydride battery scrap

New nickel hydride alloys have been developed to replace the cadmium-containing negative electrodes of nickel-cadmium batteries. The new, cadmium free alloys promise enhanced electrochemical properties as well as reduced environmental toxicity. Rechargeable batteries using nickel hydride electrodes are strong candidates for electric vehicle applications. The U.S. Bureau of Mines is investigating hydrometallurgical technology that separates and recovers purified metallic components present in nickel hydride battery scrap. A preliminary investigation of acid dissolution and metal recovery techniques using whole batteries and electrode rolls has shown potential options that will allow the successful recycling of much of the battery fabrication scrap.     

Electrochemical characterization of vacuum sintered copper alloyed austenitic stainless steel

The aim of this work is the study of the electrochemical behaviour and corrosion resistance of copper alloyed vacuum sintered stainless steel. The presence of copper can improve the passivability of sintered stainless steel and, as a consequence, the corrosion resistance; moreover, vacuum sintering allows materials with good chemical and mechanical properties to be produced, avoiding the interaction between the metal and the sintering atmosphere. Microstructural characterization was carried out: copper evaporation during sintering and a different solubility of copper in AISI 304L and AISI 316L were indicated. This last result was related to the surface oxides stability of the steels in the sintering condition. The electrochemical characterization in an acid environment showed different behaviour as a function of the copper amount and of its presence as solid solution. These results were compared with similar measurements of wrought materials or samples sintered in a nitrogen-containing atmosphere.     

The influence of powder apparent density on the density in direct laser-sintered metallic parts

In direct laser sintering, the density is expected as high as possible for the industrial application. Since the density not only determines the industrial acceptance, but also limits the accuracy of the parts. This paper reports on the influence of the powder apparent density on final density of the sintered part's in direct laser sintering of Cu-based metal powder. The relative densities of the sintered parts with the different apparent densities using different process parameters have been investigated. The result shows that the apparent density has the most significant effect on final density of the sintered part. The final density increases with the increase of the apparent density. It is easy to get a higher final density in direct laser sintering process if a higher apparent density is used. However, the final density seems to have an upper limit for a given metal powder system.     

贮氢电极合金电化学容量的评价方法

设计了三种电化学测试系统并进行金属氢化物电极电化学性能对比分析，结果表明，开口式三电极系统测出的放电容量明显高于夹片式和模拟电池系统所测出的放电容量，夹片式电极系统测试的结果和模拟电池系统测试的结果比较一致。     

Microstructural evolution during direct laser sintering of multi-component Cu-based metal powder

A multi-component Cu-based metal powder was chosen for direct laser sintering. The powder consists of a mixture of high-purity Cu powder, pre-alloyed CuSn and CuP powder. Liquid phase sintering with complete melting of the binder （CuSn） but non-melting of the cores of structural metal （Cu） proves to be a feasible mechanism for laser sintering of this powder system. The microstructural evolution of the sintered powder with variation of laser processing parameters was presented. High sintering activities and sound densification response were obtained by optimizing the laser powers and scan speeds. Using a high laser power accompanied by a high scan speed gives rise to baUing effect. At a high laser power with a slow scan speed the sintering mechanism may change into complete melting/solidification, which decreases the obtainable sintered density. The role of additive phosphorus in the laser sintering process is addressed. Phosphorus can act as a fluxing agent and has a preferential reaction with oxygen to form phosphatic slag, protecting the Cu particles from oxidation. The phosphatic slag shows a concentration along grain boundaries due to its light mass as well as the short thermal cycle of SLS.     

溶液浸渍法制备镍金属布的研究

以涤纶布和粘胶纤维布为基体,采用溶液浸渍法并在氢气气氛下还原烧结制备了镍金属布。用扫描电子显微镜、X射线衍射研究了不同工艺对镍金属布显微结构和相成分的影响,并通过TG-DTA分析研究了还原烧结过程中的反应机制。结果表明：选用粘胶纤维布作为基体,在NiCl2溶液中浸渍后,置于氢气气氛中900 ℃还原烧结,即可制备出连续、完整、柔韧性较好的镍金属布。     

Vergrößerung der realen Oberfläche von Kupferfolie durch elektrochemisches Behandeln bei überkritischen Stromdichten

Increasing the real surface area of copper foil by electrochemical treatment at supercritic current densities In order to increase the effective surface area of galvanically obtained copper foil the latter are subjected to an electrochemical treatment. The Efficiency of the different treatment conditions employed is evaluated in terms of capacity measurements. The authors have investigated the influence of the duration of treatment on the capacity changes (i.e. the area) of the double layer at the metal/electrolyte boundary, and the influence of the fixing duration on the efficieny of the treatment at different current densities.