IMPROVEMENT OF THE KINETIC PROPERTIES OF MINi3.7Co0.6Mn0.4Al0.3 HYDRIDE ELECTRODE BY TREATMENT OF AN ALKALINE SOLUTION CONTAINING POTAS SIUM BOROHYDRIDE

The effect of the powder of alloy electrode treated by 6 mols/L KOH solution containing y mosl/L KBH4 (y=0.0, 0.005, 0.01, 0.02, and 0.03) on the kinetic properties of electrode has been systematically studied. The results show that kinetic properties of electrode, including high rate dischargeablilty HRD, exchange current density I0s, limiting current density IL, diffusion coefficient of hydrogen in phase D have been improved markedly after treatmenst. Furthermore, the higher the concentration of KBH4, the better the kinetic properties are. The improvement of diffusion coefficient of hydrogen in or phase D. is lower than that of exchange current density IO when the concentration of KBH4 is constant. This improvement of kinetic properties leads to the decrease of overpotential of anodic and cathodic polarization.