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

利用氢化物生成热与原子半径的关系设计了10种MH-Ni二次电池用合金，用高频熔炼法制备了Abs系和AB_2系合金，并进行了热处理。将AB_5和AB_2：C_(15)、C_(14)三种合金在200目以下用砂浆粉碎，用球磨机进行机械研磨。研究了这些合金粉末的晶体结构变化和吸附-脱附特性，并用球磨机将合金成分的金属粉末制成合金。(1)铸态合金的特性大多数合金都具有沿设计方向的电化学特性。这一事实证明了我们的联合设计方法的可靠性是高的。(2)当球磨机容器…的盖子被氧化时，从球磨机容器中喷射粉碎的合金粉末的方法合金粉末样品受到氧化更多的是在空中开放的。为了防止这种氧化，在球磨机容器中注入有机溶剂后取出样品，注入乙醇的样品的电化学性能最好。(3)合金粉末的机械研磨效果本研究所用合金为：MmNi_&lt；41&gt；Co_&lt；0.4&gt；Mn_&lt；0.2&gt；Al_&lt；0.3_Fe_&lt；0.1&gt；(AB_5-系统)，Zr_&lt；0.95&gt；Ti_&lt；0.05&gt；(V_&lt；0.10&gt；Ni_&lt；0.57&gt；Mn_&lt；0.28；铬；0.05；)2.1(AB_2，C15型)和Zr_&lt；0.65；Ti_&lt；0.35&gt；(V_&lt；0.10；Ni_&lt；0.57；gt；Mn_&lt；0.28&gt；Co_&lt；0.05&gt；)1.82(AB_2，C14型)，MG加工5-200(或425)小时。随着加工时间的延长，这些合金粉末变为非晶态，在加工结束时，微晶尺寸达到了几个纳米。P-C-T曲线上的最大氢含量随MG处理时间的增加而降低，平衡氢压(平台中心附近)随MG处理时间的增加而增大。另一方面，随着MG处理时间的增加，电化学容量下降。(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提高