用电镀方法在贮氢合金粉末表面包覆铜的探索

设计了一种专用电镀装置：阳极为石墨或不锈钢等制成的不溶性阳极；阴极为贮氢合金粉末和承接部分组成的复合阴极；还有保证阴阳极相对运动的机械传动部分——供液和供料部分。采用特殊的电镀方法对贮氢合金粉末进行包覆Ｃｕ处理：随着阴阳极的相对运动，合金粉末和电镀液一起进入阴阳极之间，电镀液在粉末的间隙中流动，在电场作用下Ｃｕ２＋在粉末的表面放电而沉积，获得均匀镀层。主要工艺参数为：电压６Ｖ～１２Ｖ，电流密度２０Ａ／ｄｍ２～４０Ａ／ｄｍ２，阴阳极相对运动速度２ｍ／ｍｉｎ～４ｍ／ｍｉｎ。此方法易于控制铜的包覆总量，制成的镀铜贮氢合金电极具有较好的充放电循环稳定性和较高的电化学容量。     

基于内压控制氢镍电池充满的研究

当MH/Ni电池充满电后,必须能够及时地停止充电。通过分析电池的工作原理,发现在充电末期,正是电池内部的气体压力促使了温度的升高和充电电压的降低,所以提出用内压控制氢镍电池充满的思想。通过记录氢镍电池在充电过程中的内压,电压及温度的变化情况,并对数据进行了分析与研究,发现内压变化提前于电压及温度的变化,认为用内压来作为终止充电的信号,可比用负电压及温度来控制更及时、准确。     

CO2 sequestration in depleted methane hydrate deposits with excess water

The recent increase in atmospheric CO₂ concentration makes it necessary to investigate new ways to reduce CO₂ emissions. Simultaneously, natural gas hydrate mining technology is developing rapidly. The use of depleted methane hydrate (MH) deposits as potential sites for CO₂ storage is relatively safe and economical. This method can alleviate the shortage of hydrate displacement gas with CO₂. The purpose of this study was to investigate CO₂ hydrate formation characteristics during the seepage process—in reservoirs with excess water—and their effect on CO₂ storage. The experimental process can be divided into 5 parts: MH formation, water injection, MH dissociation, CO₂ hydrate formation, and CO₂ hydrate dissociation. Magnetic resonance imaging was employed to monitor the distribution of liquid water, and the effects of different parameters on the formation and dissociation of CO₂ hydrates were analyzed. It was found that a state of initial water saturation can effectively control hydrate saturation in artificial MH reservoirs for hydrate reservoirs with excess gas. In the process of CO₂ flow, initial water saturation was not the main controlling factor for CO₂ hydrate formation. Increasing the flow pressure and reducing the flow rate were beneficial for CO₂ hydrate formation. This study is of great significance for advancing the science of CO₂ geological storage in the form of deep‐sea hydrates.     

镍氢电池用PVA-TiO_2聚合物电解质膜

通过钛酸四丁酯的原位水解制备聚乙烯醇(PVA)-Ti O2碱性聚合物电解质膜,用傅里叶变换红外光谱(FT-IR)、SEM、交流阻抗和循环伏安法分析电解质膜的结构与电化学性能。在室温条件下,PVA-6%Ti O2聚合物电解质的碱吸率和电导率最高,分别为105%和0.023 S/cm,电化学稳定窗口为-1.0~1.0 V;将PVA-Ti O2碱性电解质膜组装成以Mg3Mn Ni2储氢合金为负极材料的聚合物镍氢(MH/Ni)电池,以15 m A/g在0.4~1.5 V循环12次,放电比容量稳定在150 m Ah/g左右。     

Effects of V content on hydrogen storage properties of V–Ti–Cr alloys with high desorption pressure

Hydrogen storage is one of the most important issues to realize hydrogen society especially for on-board usage. Recently, high-pressure metal hydride (MH) tank attracts many attentions due to its high volumetric hydrogen storage density and relatively easy heat management. To emphasize its merits, further improvements of properties of MH, such as capacity, hydrogen desorption capability at low temperature and durability, are required. In this paper, V–Ti–Cr alloys of V-rich compositions were investigated with perspective of increasing of hydrogen desorption pressure and durability. In both of 60at%V–Ti–Cr and 80at%V–Ti–Cr alloys, good relationship between hydrogen desorption pressure and Ti content was observed. In comparing with 60at%V–Ti–Cr alloys, 80at%V–Ti–Cr alloys showed good durability. It is quite notable that relationship between limitation line (upper substitution limit of Ti by Cr without degradation of hydrogen capacity) and desorption pressure for V–Ti–Cr ternary system with V-rich composition is clarified. And also, it is revealed that in the case of V–Ti–Cr ternary system, not only Ti/Cr ratio but also V content is important factor to obtain alloys with high hydrogen desorption pressure. 75at%V–5at%Ti–Cr as-cast sample showed good durability, hydrogen desorption capability at low temperature and relatively high effective hydrogen capacity simultaneously.     

镍氢电池充放电终止指标的实验研究

进行了镍氢电池的充放电实验,检测了电池工作时的电压、容量、温度和内阻,绘制了相应的曲线.上述4个参数的变化显著程度不同.借助曲线,讨论了镍氢电池充放电终止指标的确定原则.充电时,电池电压、容量和电池的温度可作为终止指标.放电时,电池的电压、容量和内阻可作为终止指标.总体而言,用容量作为充放电的终止指标比较准确,由此提出了以电池容量作为充放电终止指标的建议,所得到的结论对不同容量的镍氢电池具有参考意义.     

现代计算机辅助技术在MH-Ni电池研究中的应用

采用计算机辅助技术模拟材料的性能是新兴的研究领域 ,经过十多年的研究与发展 ,MH Ni电池领域已经积累了大量的经验和数据 ,利用计算机辅助技术系统研究MH Ni电池已经引起广泛关注。综述了国内外现代计算机辅助技术在MH Ni电池的基础研究和产业化过程中的应用情况 ,主要涉及电池热力学、动力学研究 ,电池理化性能检测 ,电池系统设计 (包括负极用贮氢合金设计、镍正极设计、电池制作 )和电池均匀性研究。充分有效利用现代计算机辅助技术 ,将会大大加快MH Ni电池的研究与产业化发展的步伐。     

球形Ni(OH)2XRD线谱与制备工艺的关系

研究了球形Ni(OH) 2 XRD线谱的变化对提高MH /Ni电池容量的影响。实验表明Ni(OH) 2 在制备过程中随结晶粒度的变化 ,其XRD线谱呈不同程度的选择性宽化 ,这又与反应的 pH值、氨镍比、温度、搅拌效果和添加剂有重要关系。要制备高活性球形氢氧化镍 ,必须综合考虑以上因素。     

MH/Ni 电池的发展现状

介绍了MH /Ni电池的发展现状。具体而言介绍了MH /Mi电池材料制备工艺的进展 ,国内外电池产业化现状 ,与国外相比的差距 ,应用市场发展方向。最后介绍了MH/Ni电池的发展前景     

大容量方形动力MH/Ni电池性能

研究了35Ah/1 2V和40Ah/1 2V大容量方型动力MH/Ni电池的容量、电压、快速充放电、充电内压性能和阻抗特性。结果表明:研制的方型动力MH/Ni电池可以封口化成;电池的容量达到设计容量,其中正极活性物质的利用率达90%以上;充电内压较低,充电效率较高。快速放电性能较好,如40Ah电池1C倍率放电容量为0 2C时的98%;快速充电性能好,40Ah电池在1C倍率快速充电的条件下,其0.2C倍率放电容量接近40Ah。