Correlation between crystal structure and electrochemical properties of C14 Laves-phase alloys

By examining the relationships between the structure and the thermodynamic and electrochemical properties for Zr1-xTix(V0.1MnaNibEc)(alpha) (x=0.1-0.3, a=0.28-0.30, b=0.50-0.57, c=0.05-0.12, alpha=1.6-1.8, E=Co, Fe, Mo) alloy system with C14 type structure, the following results were obtained. The partial molar enthalpy for hydride formation decreases linearly with decreasing cell volume V-C14 of the C14 phase. This means that the hydride becomes unstable with decreasing V-C14, as is the case for the C15 type structure. Both -Delta H and V-C14 decrease with decreasing average atomic radius of the alloy, and the correlation coefficient was sufficiently high for each value. The discharge capacity and dischargeability also depend on -Delta H and V-C14.