An Electrochemical Investigation of the EDTA Influence on the Cobalt-Manganese Electrodeposition in Aqueous Chloride Electrolytes

摘要

After subsequent proper heat treatment, a Co-Mn alloy coating is potentially a protective and conductive coating on ferritic stainless steel interconnects in solid oxide fuel cells. In this paper, we use electrochemical measurements to report the effects of EDTA (disodium ethylenediaminetetraacetate) in a chloride electrolyte on the Co-Mn electrodeposition process. The addition of EDTA to the chloride electrolyte significantly shifts the reduction reaction potential of cobalt in a more negative direction while slightly altering the discharging potential of manganese and most importantly, shortening to a great extent the discharge potential difference between Co2+ and Mn2+. Also, it is crucial to control the [Co2+]/[EDTA] ratio to form completely complexed cobalt ions and a very small amount of complexed manganese ions, and thus to promote the deposition of the Co- Mn alloy. The addition of EDTA to the chloride electrolyte is a promising way to prepare a Co-Mn alloy coating via electrodeposition.