Electroplating using copper, illustration. Electrolysis is used to electroplate objects. A metal object such as a key is connected to the negative terminal of the power supply. A piece of copper is connected to the positive terminal, forming an anode. The electrolyte is copper sulphate solution. The electric current releases positive copper ions into solution, which then deposit on the negatively charged key as solid copper. The key gradually gets coated with pure copper as the positive electrode gradually dissolves.