GAS-DIFFUSION CATHODE AND ITS MANUFACTURING METHOD Russian patent published in 2005 - IPC

FIELD: electrochemistry; manufacture of cathodes for chemical power supplies.

SUBSTANCE: proposed gas-diffusion cathode has active layer of activated carbon and binder, water-repellant layer of industrial carbon and binder, as well as current-carrying grid; active layer incorporates in addition industrial carbon; fluoroplastic is used as binder for active and water-repellant layers, proportion of ingredients being as follows, mass percent: water-repellant layer: industrial carbon, 60 - 80; fluoroplastic, 20 - 40; active layer: industrial carbon, 20 - 30; activated carbon, 60 - 70; fluoroplastic, 5 - 10. Proposed method for cathode manufacture includes production of masses for water-repellant layer and for active layer, manufacture of current-carrying grid, coating of the latter with active and water-repellant masses; water-repellant mass is produced from mixture of industrial carbon and fluoroplastic taken in following proportion, mass percent: 60 - 80 and 20 - 40, respectively; active mass is produced from mixture of industrial carbon, activated carbon, and fluoroplastic taken in following proportion, mass percent: 20 - 30, 60 - 70, and 5 - 10, respectively; mentioned mixtures are compressed on different sides of current-carrying grid. Active mass is applied in predetermined amount to auxiliary substrate, leveled, and current-carrying grid is mounted on active mass; then grid is coated with predetermined amount of water-repellant mass which is leveled and industrial substrate is placed on this mass; upon compression auxiliary substrates are removed. Compression is conducted at pressure of 460 - 480 kg/cm² and sintering, at temperature of 340 - 360 °C for 20 - 40 minutes.

EFFECT: enhanced service life of cathode.

9 cl