Lightweight electrodes for use in an electrochemical device are described. In one embodiment the lightweight electrodes comprise a catalyst layer including an admixture of catalyst and a fluorinated phosphonitrile polymer. In another embodiment the hydrophobic backing layer is a continuous film of fluorinated phosphonitrile polymer with a contiguous layer of catalyst thereon. The catalyst can also be admixed and bound with particles comprising the same fluorinated phosphonitrile polymer used as the backing layer, derivatives of the polymeric material or other hydrophobic polymers such as polytetrafluoroethylene. The electrode is adapted to be disposed in an electrochemical cell with the catalytic layer in contact with the cell electrolyte.