RELATIONSHIP BETWEEN CRYSTAL CHARACTERISTICS AND ELECTROCHEMICAL PROPERTIES OF Zr BASED HYDROGEN STORAGE ALLOY
Zr系贮氢合金晶体结构与电极特性间关系

The electrochemical discharge capacity is in close relation with its crystal characteristics of AB2 type Laves phase hydrgoen storage alloy ZrCr0.4 Mn0.2V0.1Ni0.3, its capacity decreased shapoly from 324 mA · h / g to 25 mA · h / g after amorphization by mechanical milling of the crystalline (as-cast) alloy with stainless steel balls. Hydrogen atoms stored in the Zr2B2(B=Cr, Ni or V) tetrahedral interstitial sites of as-cast alloy lattice mainly contributed to its electrochemical capacity. However, for the amopohous alloy with the same composition the contribution to the electrochemical capacity is mainly resulted from the hydrogen atoms in Zr3B and Zr4 sites. It is believed that only haif sites in the crystilline or amorphous alloys can adsorb and desorb hydrogen atoms reversely. Extra energy induced during milling process can reduce the potential of electrochemical discharging of hydrogen reaction. Correspondent: YANG Xiaoguang, lecturer, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027