Effect of nanometer-sized WC additive on the electrochemical behaviors of AB(2) - type hydrogen storage alloy

The nanometer-sized WC powders were evidently found to catalytically decomp ose the molecular water and chemical-adsorb hydrogen atoms in alkaline solu tion. The WC additive also accelerated the combination reaction of hydrogen in the hydride electrode during cathodic polarization (charging), inducing rapid H-2 emission. Electrochemical impedance analysis (EIS) showed that t he hydrogen atoms adsorbed on the surface of WC powders were first electroc hemically oxidized due to their lower chemical bonding, and that the low co nductivity of WC powder increased the internal resistance of hydride electr odes. (C) 1999 Elsevier Science S.A. All rights reserved.