Abstract: A method may activate a fuel cell including a plurality of electrochemical cells in a stack, the fuel cell being intended to operate, during at least one nominal operating phase, as an electric generator. Such a method may include, during an activation phase by electrolysis, prior to the at least one nominal operating phase: electrically supplying the fuel cell by an external electric generator, the electric supply being configured to apply an activation voltage greater than the voltage of the cell in an open circuit (OCV); fluid supplying a humid gas fluid at a first electrode and/or a second electrodes. The humid gas may have a relative humidity (RH) such that 40%?RH<100%. The fuel cell may operate in electrolysis during the activation phase called by electrolysis.

Abstract: The present invention relates to an electrochemical lead battery comprising at least one electrochemical cell comprising a positive electrode comprising lead oxide PbO2 and a negative electrode comprising lead metal separated by an electrolyte comprising methanesulfonic acid and at least one lead salt, characterized in that said electrolyte further comprises fluoride ions.