An anode of a cell for the electrowinning of aluminium comprises a
nickel-iron alloy substrate having an openly porous nickel metal rich
outer portion whose surface is electrochemically active. The outer portion
is optionally covered with an external integral nickel-iron oxide
containing surface layer which adheres to the nickel metal rich outer
portion of the nickel-iron alloy and which in use is pervious to molten
electrolyte. During use, the nickel metal rich outer portion contains
cavities some or all of which are partly or completely filled with iron
and nickel compounds, in particular oxides, fluorides and oxyfluorides.
