快淬AB5型贮氢合金研究

使用快淬工艺制备了两种成分的ＡＢ５型贮氢合金并做了电化学充放电循环实验,比较了它们的起始活化性能、放电容量、电化学循环稳定性、放电电压性能等。发现快淬合金的电化学循环稳定性明显优于铸态合金,放电电压平台性能也较好,但快淬导致起始活化速度慢,放电容量也有所降低。快淬对放电电压平台高低的影响随合金成分的不同而改变     

铸态和快淬态Mm(NiCoMnAl)5合金的电化学性能及相结构

本文研究了铸态和快淬态MmNi3．7Co0．6Mn0．4Al0.3贮氢合金的电化学性能和相结构。电化学测试结果表明：快淬态合金的活化性能比铸态合金差，淬速为10m／s和16m／s的快淬态合金的最大放电容量高于铸态合金，放电电压平台更为平坦。淬速为22m／s和28m／s的快淬态合金的最大放电容量低于铸态合金。随着淬速的增加，合金电极的循环稳定性提高。X射线衍射结果表明：铸态和快淬态合金均由CaCu5型主相和一个第二相组成，快淬使得第二相衍射峰减弱。合金成分更为均匀。快淬态合金的晶格参数大于铸态合金。晶格参数的增加是快淬合金具有良好循环稳定性的一个重要原因。     

快淬对RE-Mg-Ni-Mn系AB_2型贮氢合金结构及电化学性能的影响（英文）

为了提高合金的电化学性能,采用Ce部分替代La,并结合快淬方法制备了La_(1–x)CexMgNi_(3.5)Mn_(0.5)(x=0,0.1,0.2,0.3,0.4)贮氢合金。XRD和SEM测试结果表明,合金由LaMgNi_4主相以及LaNi_5第二相组成。随着快淬速度的增加,合金的晶格参数及晶胞体积逐渐增大,晶粒明显得到细化。电化学测试结果表明,铸态及快淬态合金具有优异的活化性能,其放电容量均在第一次循环时即可达到最大值。随着快淬速度的增加,合金的放电容量先增大后减小,但其循环稳定性逐渐提高。此外,合金电极的电化学动力学性能均随快淬速度的增加先提高后降低。     

快淬对低钴贮氢合金的电化学性能影响

为改善低钴贮氢合金的综合电化学性能,对其进行不同速度的快淬处理.结果表明:合适的快淬速度不仅可以大幅度的提高放电容量,而且明显的改善合金的循环稳定性和放电电压特性.18 m/s快淬低钴合金具有较好的综合电化学性能.但快淬使得合金的活化性能有所降低.利用X射线衍射、扫描电镜对铸态及快淬合金进行微观分析,讨论了快淬对低钴贮氢合金电化学性能的影响机理.     

快淬对低钴贮氢合金的电化学性能影响

为改善低钴贮氢合金的综合电化学性能,对其进行不同速度的快淬处理。结果表明,合适的快淬速度不仅可以大幅度的提高放电容量,而且明显的改善合金的循环稳定性和放电电压特性。18 m/s快淬低钴合金具有较好的综合电化学性能,但快淬使合金的活化性能有所降低。利用X射线、扫描电镜对铸态及快淬合金进行微观分析。分析了快淬对低钴贮氢合金电化学性能的影响机理。     

快淬对低钻贮氢合金的电化学性能影响

为改善低钴贮氢合金的综合电化学性能，对其进行不同速度的快淬处理。结果表明：合适的快淬速度不仅可以大幅度的提高放电容量，而且明显的改善合金的循环稳定性和放电电压特性。18m／s快淬低钴合金具有较好的综合电化学性能。但快淬使得合金的活化性能有所降低。利用X射线衍射、扫描电镜对铸态及快淬合金进行微观分析，讨论了快淬对低钴贮氢合金电化学性能的影响机理。     

快淬对La0.7Mg0.3Co0.45Ni2.55-xCux (x=0-0.4)电极合金微观结构及电化学性能的影响

应用铸造及快淬工艺制备了La0 7Mg0.3Co0.45Ni2.55-xCux (x=0, 0.1, 0.2, 0.3, 0.4)贮氢电极合金,研究了快淬工艺对合金微观结构及电化学性能的影响.XRD,SEM及TEM的分析结果表明,铸态及快淬态合金具有多相结构,包括(La,Mg)Ni3相,LaNi5相以及LaNi2相.快淬对合金的相组成没有明显影响,但显著地改变了合金的相丰度.快淬还显著地改善合金的成分均匀性,并使合金的晶粒明显细化.电化学测试的结果表明,快淬大幅度提高合金的电化学循环稳定性,但使合金的放电容量和活化性能下降.快淬对合金的放电电压特性具有明显的影响,当淬速大于15m/s时,快淬降低合金的放电电压,并使放电平台的斜率明显增大.     

铸态及快淬态La2Mg（Ni0.85Co0.15）9Crx（x=0～0.2）电极合金的微观结构及电化学性能

为了提高La-Mg-Ni系（PuNi3）型贮氢合金的电化学循环稳定性,在La2Mg（Ni0.85Co0.15）9合金中加入微量Cr,用铸造及快淬工艺制备了La2Mg（Ni0.85Co0.15）9Crx（x=0,0.1,0.2）贮氢合金.分析测试了铸态及快淬态合金的电化学性能及微观结构,研究了Cr对铸态及快淬态合金微观结构及电化学性能的影响.结果表明,铸态及快淬态合金具有多相结构,包括（La,Mg）Ni3相（PuNi3结构））,LaNi5相和一定量的LaNi2相.快淬对合金的相组成没有影响,但使合金的相丰度产生变化.Cr的加入提高了铸态及快淬态合金的循环稳定性,但使合金的容量下降.合金的循环寿命随淬速的增加而增加,铸态及快淬态合金均有优良的活化性能.     

快淬纳米晶/非晶Mg2-xLaxNi (x=0~0.6)合金的电化学贮氢性能

用铸造及快淬工艺制备Mg2Ni型Mg2-xLaxNi(x=0,0.2,0.4,0.6)贮氢合金。用XRD、SEM、HRTEM分析铸态及快淬态合金的微观结构。结果发现,在快淬无La合金中没有出现非晶相,但快淬含La合金显示了以非晶相为主的结构。用DSC研究快淬合金的热稳定性,表明La的含量及快淬对非晶相的晶化温度影响很小。电化学测试结果表明,铸态合金的放电容量随La含量的增加而增加,快淬态合金的放电容量随La含量的变化有极大值。La替代Mg显著地提高了铸态及快淬态合金的循环稳定性。     

A组分变化对AB2型储氢合金组织结构及电化学性能的影响

设计了两种成分AB2型合金,（Zr1-XTiX）（NiVMnCo）2＋α,采用XRD、SEM、TEM以及电化学性能测试方法分别对它们的铸态、快淬态及快淬态经过773 K、973 K和1 173 K退火处理的合金进行研究,结果表明,在AB2型储氢合金中加入少量Ti,可以增加电极的放电容量,提高循环寿命。熔体旋转快淬制备的非晶态合金电极的电化学性能差。快淬样品经过退火后,可获得纳米晶结构,能够大幅度提高电极材料的放电容量（370 mAh/g）和循环寿命（300次循环后容量衰减3%）。     

Research of heat treatment of low-Co AB_5 type hydrogen storage alloys for MH-Ni batteries

The effects of low-Co AB5 type hydrogen storage alloys prepared by quenching and annealing on the performances of MH-Ni batteries were investigated, and the characteristics of the low-Co AB5 type hydrogen storage alloys were compared with those of the high-Co AB5 type hydrogen storage alloy as well. The results showed that the faster the cooling of the low-Co hydrogen storage alloy is, the better homogeneity of the chemical composition for the alloy and the longer cycle life of the battery are, but the electrochemical discharge capacity and high-rate discharge ability are reduced. The high-rate discharge ability and charge retention of MH-Ni batteries for the conventional as-cast annealed low-Co hydrogen storage alloy were superior to those for the rapidly quenched low-Co hydrogen storage alloy and the high-Co hydrogen storage alloy, but a little inferior in the cycle life.     

Electrochemical performances of hydrogen storage alloys treated using a new milling technique

A new self-made additive of amidocyanogen-acetic salt was used in wet bail-grind technique (WBGT) for preparing hydrogen storage alloys, and the effect on the electrochemical performance of the alloy electrode was investigated in detail. It was found that the prepared electrode had perfect electrochemical performances, such as rapid activation, high capability, high-rate discharge (HRD) ability, and good stability. The first discharge capacitance at 0.2 C (throughout this study, n C rate means that the rated capacity of a hydrogen storage alloy (full capacity) is charged or discharged completely in 1/n h) reached 278mAh.g-1 and the discharge capacitance reached the maximum of 322mAh·g-1 only after two charge-discharge cycles. For the dry method, wet method, and WBGT, the high rate discharge (HRD) values (C5C/C0.2C ratio) were approximately 0.59, 0.76, and 0.83, respectively. The stable discharge capacity at 3 C increased from 275mAh·g-1 (dry method) to 295mAh·g-1 (WBGT).     

Effects of substituting Ni with M (M=Cu, Al and Mn) on microstructures and electrochemical characteristics of La-Mg-Ni system (PuNi3-type) electrode alloys

In order to improve the electrochemical cycle stability of La-Mg-Ni system (PuNi3-type) hydrogen storage alloy, Ni in the alloys was partially substituted by M (M=Cu, Al, Mn). A new La-Mg-Ni system electrode alloys La0.7Mg0.3Ni2.55-xCo0.45Mx (M=Cu, Al, Mn;x =0,0.1) were prepared by casting and rapid quenching. The effects of element substitution and rapid quenching on the microstructures and electrochemical performances of the alloys were investigated. The results by XRD, SEM and TEM show that the alloys havea multiphase structure, including the (La, Mg)Ni3 phase, the LaNi5 phase and the LaNi2 phase. The rapid quenching and element substitution have an imperceptible influence on the phase compositions of the alloys, but both change the phase abundance of the alloys. The rapid quenching significantly improves the composition homogeneity of the alloys and markedly decreases the grain size of the alloys. The Cu substitution promotes the formation of an amorphous phase in the as-quenched alloy, and a reversal result by the Al substitution. The electrochemical measurement indicates that the element substitution decreases the discharge capacity of the alloys, whereas it obviously improves the cycle stability of the alloys. The positive influence of element substitution on the cycle life of the alloys is in sequence Al＞Cu＞Mn, and negative influence on the discharge capacity is in sequence Al＞Mn＞Cu. The rapid quenching significantly enhances the cycle stability of the alloys, but it leads to a different extent decrease of thedischarge capacity of the alloys.     

热处理对包含正二十面体准晶相Ti1.4V0.6Ni合金电极的电化学性能的影响（英文）

研究了热处理前后Ti1.4V0.6Ni合金的结构和电化学性能。采用X射线粉末衍射(XRD)方法分析合金的结构。电化学特性包括放电容量、循环稳定性和高倍率放电性能等。XRD衍射分析表明,在590°C热处理30min的合金,主要包含正二十面体准晶相、Ti2Ni(FCC)相、V基固溶相(BCC)和C14Laves相(Hex)。电化学测试显示,热处理后在30°C和放电电流密度为30mA/g的条件下,合金电极的最大放电容量可达330.9mA·h/g,并且循环稳定性和高倍率放电性能也得到改善。此外,通过电化学阻抗和合金内部氢的扩散系数研究了合金电极的动力学性能。     

Effects of rapid quenching on microstructures and electrochemical properties of La_(0.7)Mg_(0.3)Ni_(2.55)Co_(0.45)B_x(x=0-0.2) hydrogen storage alloy

1 Introduction Ni-MH batteries have been used widely by virtue of several of their advantages, such as high capacity, capable of performing a high rate charge/discharge, high resistance to overcharging and over-discharging, a long cycle life, environment…     

Effects of Rapid Quenching on Structure and Hydrogen Storage Characteristics of Mg20Ni10-xMnx (x=0-4) Alloys

为了改善Mg2Ni型合金的贮氢性能,用Mn部分替代合金中的Ni,并采用快淬工艺制备Mg20Ni10-xMnx(x=0, 1, 2, 3, 4)合金。用XRD和HRTEM分析了铸态及快淬合金的微观结构,用自动控制Sieverts设备测试合金的吸放氢动力学,并采用程控电池测试仪测试合金的电化学性能。结果表明,当淬速为20 m/s时,快淬(x=4)合金中出现非晶相,且非晶化程度随淬速的增加而增加。合金的吸放氢量及动力学性能随淬速的增加而增加。此外,快淬显著地改善了合金的电化学性能,包括放电容量及含Mn合金的循环稳定性。