Abstract
tElectrodeposition in Ionic Liquid (IL) media is being widely used to obtain different metals, alloys andmore recently binary compounds. However, the understanding of this process is still slim due to poorknowledge in the chemistry of ILs and also the complex structure of the double layer at the electrode sur-face. It is then difficult to predict deposition conditions when trying to synthesize a desired deposit. In thiswork, we provide insight into the processes taking place at the electrode by detailed studies of Co2+reduc-tion in ionic liquid media at elevated temperature, which have revealed an unusual Cyclic Voltammetryprofile. A drastic drop in the reaction rate was observed, together with a well-shaped reduction peak dur-ing the oxidation sweep. Using Electrochemical Quartz Crystal Microbalance, Impedance Spectroscopymeasurements and varying bath parameters, we ascribed those phenomena to the reconstruction of thedouble layer structure upon imposed polarization. Similar behaviors were observed for other systems(Mn2+, Ni2+, Zn2+). Finally, this work provides new insight into the electrochemical processes in ILs. Weanticipate that it will also result in significant improvement in preparing metal and other deposits in theionic liquid media.