An in situ carbon-grafted alkaline iron electrode for iron-based accumulators

Abstract

An in situ carbon-grafted alkaline iron electrode prepared from the active material obtained by decomposing the α-FeC₂O₄·2H₂O–polyvinyl alcohol (PVA) composite at 600 °C in a vacuum is reported. The active material comprises a mixture of α-Fe and Fe₃O₄ with the former as the prominent component. A specific discharge capacity in excess of 400 mA h g⁻¹ at a current density of 100 mA g⁻¹ is obtained with a faradaic efficiency of 80% for the iron electrode made from carbon-grafted active material (CGAM). The enhanced performance of the alkaline iron electrode is attributed to the increased amount of metallic iron in the active material and its concomitant in situ carbon grafting.