Effect of alloys modified by an alkaline solution containing potassium borohydride on the kinetic properties of MlNi(3.7)Co(0.6)Mn(0.4)Al(0.3) hydride electrode

This paper describes the effects of treating the alloy powder of an electro de with 6 M KOH solution containing y M KBH4 (y = 0.0, 0.005, 0.01, 0.02 an d 0.03) on the kinetic properties of the electrode, including high rate dis chargeablilty HRD, exchange current density I-0, symmetry factor beta, limi ting current density I-L, diffusion coefficient of hydrogen in the alpha-ph ase D-alpha, and electrochemical polarization eta(e) and concentration pola rization eta(c). The results show that the kinetic parameters HRD, I-0, I-L and D-alpha increase markedly with the increase in the concentration of KB H4, the eta(e) and eta(c) decrease rapidly with increasing concentration of KBH4, but the symmetry factor beta does not change. (C) 1999 Elsevier Scie nce Ltd. All rights reserved.