Abstract: The rapid development of electric vehicles demands the development of high performance nickel-metal hydride battery that is able to endure high temperature. The discharge properties of Ti_0.7Zr_0.5V_0.2Mn_1.8-xNi_x(x =0.4, 0.8,1.1,1.4,1.7)hydrogen storage alloys was investigated and its phase composition was analyzed using X-ray diffraction. The results show that the cycling life was improved as the content of nickel increases. When x =0.4,0.8,1.1 and 1.4, the main phase is MgZn₂ type C14 Laves phase and the second one is cubic TiNi phase. When x=1.7, the Laves phase structure disappears. EDAS analysis shows that the increase of nickel content is effective in suppressing the dissolution of vanadium component in alloys.

Key words:  hydrogen storage electrode alloys； high temperature electrochemical performance； phase composition