Abstract: Electrochemical cell, having a positive electrode comprising electrolytic manganese dioxide, chemical manganese dioxide, lithiated manganates, cobaltates or nickelates as electroactive component and graphite as a conductive additive, which is characterized 1. Electrochemical cell having a positive electrode comprising electrolytic manganese dioxide, chemical manganese dioxide, lithiated manganates, cobaltates or nickelates as electroactive component and graphite as a conductive additive, characterized in that said conductive additive comprises at least a thermally expanded graphite in its vermicular form, and wherein the initial graphite particle expansion degree of said expanded graphite in z-direction of the particle is greater than 80 times of its initial z-dimension, and preferably within the range of 200 to 500 times of its initial z-dimension.

Abstract: Separable nanotubes are made from a transition metal oxide, preferably from a vanadium oxide of variable valence. They show a greater oxidation resistance than the carbon-based nanotubes known so far and offer many new and economic applications. The inventive nanotubes clearly show oxidation-reduction activities and are particularly suited as an active material for catalytic reactions.