Electrochemical absorption-desorption of hydrogen on multicomponent Zr-Ti-V-Ni-Cr-Fe alloys in alkaline solution

Multicomponent Zr-Ti-V-Ni-Cr-Fe and Zr-Ti-V-Ni-Cr alloy electrodes, with various Ti and Zr ratios, have been studied in alkaline solution by means of potentiodynamic current-overvoltage and galvanostatic overpotential-time responses during long-term continuous and intermittent charge-discharge cycles, The pressure-composition isotherms for absorption/desorption of hydrogen, evaluated from the equilibrium potential, have been compared with the gas phase isotherms. The kinetic data demonstrate the reversibility of hydrogen electrosorption in the investigated systems. An increased discharge efficiency has been established for electrodes with lower values of both the activation and diffusion resistance. The alloy with Fe and Ti:Zr at the atomic ratio 2:1 prepared by using vanadium-ferro-alloy is shown to meet the requirements for the negative electrode in secondary nickel-metal hydride batteries.