Electrochemical apparatus with retractable electrode

An electrochemical cell which includes a cathode electrode, an anode electrode, an acidic electrolyte dis placed between the anode electrode and the cathode electrode, and a power source for applying a voltage between the anode electrode and the cathode electrode, characterized in that the electrode anode has a layer of electrocata cata- lead dioxide facing the acidic electrolyte, there being provided a retractor mechanism which is responsible for one or more standby conditions predetermined to retract the anode electrode from an initial position in which the electrocatalyst lead dioxide is in contact with electrolyte to a retracted position in which the lead dioxide electrocatalyst is spaced from the electrolyte.