Abstract: The fine structure and microstructure changes of electrode active materials   β-Ni(OH)2 and AB5 alloy during charge-discharge processes are studied in detail by  X-ray diffraction (XRD).Chemical physical of electrode active materials and physical conductive mechanism are elucidated.To be brief,the physical conductive mechanism of MH/Ni battery is the directional migrating and moving of hydrogen ions between the positive and negative electrodes because hydrogen atoms are deviating from the β-Ni(OH)2 lattice and inserting into AB5.

Key words: chemical physics, MH/Ni battery, phase structure and microstructure, X-ray diffraction (XRD)