Effect of metal-sulfide additives on charge/discharge reactions of the alkaline iron electrode

The effect of FeS, PbS and $Bi_2S_3$ additives on the charge/discharge reactions of porous iron electrodes in alkaline media are examined by means of steady-state galvanostatic and potentiostatic polarization, as well as by gasometric methods. It is found that these additives do not affect the reaction kinetics on fully-charged iron electrodes, but retard the rapid onset of passivation. By contrast, a distinct effect of these additives is observed on the kinetics of the hydrogen-evolution reaction during electrode charging