物理化学学报 >> 1994, Vol. 10 >> Issue (07): 644-647.doi: 10.3866/PKU.WHXB19940713

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MmB5贮氢合金的结构和性能

张玉芬, 侯勇, 王健, 宏存茂   

  1. 北京大学化学系,北京 100871
  • 收稿日期:1993-02-05 修回日期:1993-05-25 发布日期:1994-07-15
  • 通讯作者: 宏存茂

Crystal Structure and Hydrogen Absorption Properties of MmB5 Alloys

Zhang Yu-Fen, Hou Yong, Wang Jian, Hong Cun-Mao   

  1. Department of Chemistry, Peking University, Beijing 100871
  • Received:1993-02-05 Revised:1993-05-25 Published:1994-07-15
  • Contact: Hong Cun-Mao

关键词: 金属氢化物, 电极材料, X-射线衍射, 压力组成等温线

Abstract:

Pressure composition isotherms, crystal structures and electrochemical capacities of MmB_5 alloy-hydrogen systems have been investigated, where Mm represents La-rich mischmetals and B_5 take a composition of Ni_(3.8)Co_(0.5)Mn_(0.4)Al_(0.3). All these multicomponent alloys belong to CaCu_5-type hexagonal crystal structuxe. The volume of unit cell (or say, the interstitial hole size) becomes larger with increasing of La content and decreasing of Ce content in Mm. The larger interstitial hole leads to a decrease of dissociation pressure of their hydride, hence improves the stability of MmB_5H_6 and the electrochemical capacity of the MmB_5 alloy. The expansion ratio of the MmB_5 for hydrogen absorption was obviously smaller than that of LaNi_5 alloy. For MmB_5 alloy, especially with high content of La in Mm, a lot of properties for the application in MH/Ni battery, such as against pulverization, long cycle lifetime etc can be promoted.

Key words: Metalhydride, Electrode materials, X-ray diffraction, P-C Isotherms