The present invention is concerned with a protective coating with current applied on a metallic collector of an electrode. The protective coating comprises a mineral binder vitreous or partly vitreous and optionally an electronic conduction additive. This coating is applied in the form of a solution or dispersion on the collector of the electrode and dried, so that it coats and protects at least part of the surface of the metal of the collector to prevent the formation of passivation films generated by active species produced by other components of the generator.