Process for manufacturing an electrode for an electrochemical device

PCT No. PCT/IB95/00786 Sec. 371 Date Mar. 24, 1998 Sec. 102(e) Date Mar. 24, 1998 PCT Filed Sep. 25, 1995 PCT Pub. No. WO97/12382 PCT Pub. Date Apr. 3, 1997The present invention aims at improving the catalytic activity of the metallic platinum deposited on the substrate of the counterelectrode (i.e., the cathode), so as to obtain a high value of the catalytic activity on the reduction reaction of triiodide to iodide essentially independent of the nature of the solvent used in the electrolyte. To that effect, the manufacturing process according to the invention is characterized in that said metallic platinum is deposited in the form of a plurality of spheroidal microcrystallite clusters each having a size of less than about 100 nanometers, dispersed over the surface of said substrate, and in that said deposited metallic platinum is submitted to a thermal treatment, carried out at a temperature in the range of about 375 DEG to 400 C., so as to enhance the catalytic properties of the platinum on the oxido-reduction of iodine and triiodide 3I2+2e->2I3 in the redox system iodine/iodide.