ELECTROCHEMICAL-BEHAVIOR OF TEFLON-BONDED IRON-OXIDE ELECTRODES IN ALKALINE-SOLUTIONS

The electrochemical behaviour of Teflon-bonded iron oxide electrodes i n 5.35 M KOH + 0.65 M LiOH solution that contains various additives (s uch as thiourea, ethylenediaminetetraacetic acid (EDTA), hexamine and sodium sulfide) is examined by cyclic voltammetry, chronopotentiometry , open-circuit potential (OCP) decay and charge/discharge studies. The incorporation of Na2S in the alkaline electrolyte improves the perfor mance of iron oxide electrodes by increasing the value of the OCP and decreasing the transient time. Moreover, the addition of Na2S gives ma ximum capacity for the iron oxide electrode and a value of zero for dE /dt. The addition of thiourea lowers the performance of pressed iron e lectrodes. Thus, the incorporation of Na2S in the alkaline electrolyte is essential for improving the performance of these electrodes.