Morphological change and hydorogen absorption-desorption characterristics of hydorogen-absorbing alloy by meehanical alloying

机械合金化吸氢合金的形貌变化及吸放氢特性

• 批准号: 11650725
• 负责人: NAKANO Hiroaki
• 金额: $ 0.7万
• 依托单位: TOKAI UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650725/
• 关键词: Hydrogen-absorbing alloy; Machanical grinding; Hydride electrode; Ejection method of alloy powder; P-C-T curve; Nano-structure; メカニカルグラインディング; AB5合金; ボールミル; 表面酸化; ミリング物の取り出し方法; 電気化学的特性; メカニカルアロイング; 水素吸放出特性

10 kinds of alloys for Ni-MH secondary battery were designed by using the relationship between enthalpy for hydride formation and atomic radius, Designed Abs system and AB_2 system alloys were produced by using high frequency fusion fumace, and these conducted the heat treatment afterwards. 3 kinds of alloys (AB_5 and AB_2 : C15, C14) were crushed under 200 meshes by a mortar, and these samples did the mechanical grinding by using ball mill. Change of crystal structure and absorption-desorption characteristics were examined on these alloy powders In addition, an alloy was also produced from metal powders of alloy constituent element by the ball mill.(1)Characteristics of cast alloys Most of produced alloys had electrochemical characteristics along the design. This fact has proven that the reliability of our ally-design method is high (2)Ejection method of crushed alloy powder from ball mill container Alloy powder sample receives the oxidation, when the cover of the ball mill container … More is opened in the air. In order to prevent this oxidation, the sample was taken out after some organic solvents were injected to the ball mill container, Electrochemical characteristics of the sample which injected ethanol were the best. (3)Effect of mechanical grinding(MG) for alloy powders The alloys used in this study were MmNi_<41> Co_<0.4> Mn_<0.2> Al_<0.3_ Fe_<0.1>(AB_5-system), Zr_<0.95> Ti_<0.05>(V_<0.10> Ni_<0.57> Mn_<0.28> Cr_<0.05>) 2.1 (AB_2, C15 type) and Zr_<0.65> Ti_<0.35> (V_<0.10> Ni_<0.57> Mn_<0.28> Co_<0.05>) 1.82(AB_2, C14-type), and MG processing was carried out for 5-200(or 425) hour. These alloy powder became amorphous state with the increase in processing time and the crystallite size became several nano-meter in the end of processing. The maximum hydrogen content in the P-C-T curve decreased with the increase in MG processing time and the equilibrium hydrogen pressure (near the center of the plateau) tended to increase with the increase in MG processing time. On the other hand, electrochemical capacities decreased with the increase in MG processing time. (4)Mechanical alloying of alloy powder with 10% nickel powder Discharge capacity of the alloy including the 10% nickel powder slightly increased further than the alloy without Ni powder Less

利用氢化物生成焓与原子半径的关系设计了10种镍氢二次电池用合金，利用高频熔炼炉生产了Designed Abs系和AB_2系合金，并进行了热处理。将3种合金（AB_5和AB_2：C15、C14）用研钵粉碎至200目以下，并用球磨机对样品进行机械研磨。研究了这些合金粉末的晶体结构变化和吸附-脱附特性。此外，还通过球磨机由合金成分元素的金属粉末生产合金。 (1)铸造合金的特性大多数生产的合金都具有符合设计的电化学特性。这一事实证明我们的联合设计方法的可靠性很高。 (2)从球磨机容器中破碎合金粉末的排出方法当球磨机容器的盖子在空气中打开时，合金粉末样品受到氧化。为了防止这种氧化，在球磨容器中注入一些有机溶剂后取出样品，注入乙醇的样品的电化学特性最好。 (3)机械研磨(MG)对合金粉末的影响本研究所用合金为MmNi_<41>Co_<0.4>Mn_<0.2>Al_<0.3_Fe_<0.1>(AB_5系)、Zr_<0.95>Ti_<0.05>(V_<0.10>Ni_<0.57>Mn_<0.28> Cr_<0.05>)2.1(AB_2、C15型)、Zr_<0.65>Ti_<0.35>(V_<0.10>Ni_<0.57>Mn_<0.28>Co_<0.05>)1.82(AB_2、C14型)，进行5～200(或425)小时的MG处理。随着加工时间的增加，这些合金粉末变成非晶态，并且在加工结束时微晶尺寸变成几个纳米。 P-C-T曲线中的最大氢含量随着MG处理时间的增加而降低，并且平衡氢压力（平台中心附近）随着MG处理时间的增加而趋于增加。另一方面，电化学容量随着MG处理时间的增加而降低。 (4)添加10%镍粉的合金粉末的机械合金化 添加10%镍粉的合金的放电容量比不含镍粉的合金略有增加 更少