A medical electrode for conducting an electrical current to or from the skin of a patient. The electrode comprises a thin, flexible metallic conductor, a layer of electrolyte in electrical contact with the conductor and positioned to be in electrical contact with the skin when the electrode is applied to a patient, and an insulating layer overlying the conductor, wherein a peripheral edge of the metallic conductor is sealed with an insulating material so that the peripheral edge of the conductor is substantially out of electrical contact with the electrolyte. This tends to increase the shelf life of the electrode because the more highly worked (e.g., from being die cut during manufacture), and thus higher energy state, peripheral edge is electrically isolated.