ELECTROCHEMICAL PROPERTIES AND SUBSTITUTI ON EFFECT OF HYDROGEN-ABSORBING ALLOYS WITH PSEUDOBINARY LAVES PHASE

The electrochemical characteristics, thermodynamic properties and crys tal structure of Zr-V-Ni-Mn-M (M=Co,Cr,Fe) alloys with pseudobinary La ves phase were investigated. Many of these alloys had a large discharg e capacity over 350 mAh/g at 17mA/g and a good high-rate capability fo r discharge. From these electrochemical properties, the alloy that has an enthalpy (DELTAH-degrees) range of hydride formation of -36 approx imately -42kJ/mol H-2 will be used in the negative electrode for the n ickel-hydride battery. Both the average atomic radius and the average electronegativity contributed to DELTAH-degrees, and the contribution of the average electronegativity to DELTAH-degrees was greater than th e average atomic radius.