Electrochemical Deposition of Co-Mn Alloys Using CoCl2 - Mn(TfO)2 - bmimtfo Ionic Liquid Electrolytes

Abstract

Electrochemical deposition of Cobalt -Mnganese alloys was studied using CoCl2 - Mn(TfO)2 - BMIMTfO ionic liquid electrolytes. Constant potential electrolysis experiments were performed for different applied potentials at 363K in an Ar atmosphere for 2 h. The cyclic voltammograms (CV) for BMIMTfO, CoCl2 – BMIMTfO, Mn(TfO)2 - BMIMTfO and CoCl2 - Mn(TfO)2 - BMIMTfO systems were studied. The measured electrochemical window of neat BMIMTfO is 4.1V. Pure cobalt was produced by the reduction of CoCl2 in the CoCl2 – BMIMTfO system but no reduction of Mn(TfO)2 to Mn in the Mn(TfO)2 - BMIMTfO system was observed. The co-deposition of Co-Mn alloy in the CoCl2 - Mn(TfO)2 - BMIMTfO system was obtained. The SEM-EDS was used to determine the chemical composition of the alloy. The amount of Mn in Co-Mn alloy increased with increase in the applied cathode potential. The amount of Mn in Co-Mn alloy increases from 9.86 to 29.6 wt% with increasing the applied cathodic potential from –1.2 to –1.5 V respectively. The results showed that the Mn can be co-deposited with Co to form high grade Co-Mn alloy.