Process of manufacturing thin electrodes, supported on an electronically conductive sheet, the electrodes being made from an element selected from lithium, lithium alloy, or doped lithium, whose melting point does not differ from the melting point of lithium by .+-.50.degree. C. and whose thickness is constant, from a roller of the sheet and a source of the element. According to the invention, there is provided a bath of the element in molten state, the sheet is continuously unrolled, a constant quantity of the molten element is continuously applied on one of the two faces of the sheet, so as to produce a film on the sheet, whose thickness is constant and between about 0.1 and about 40.mu. and whose surface is homogeneous and uniform. The process is carried out in such a manner that the molten element is prevented from solidifying while in contact with the sheet, and the solidification of the element on the sheet takes place after formation of the film on the sheet. Electrode made of a sheet coated with a layer of lithium whose thickness is 0.1 to 40.mu..