Method and device for the manufacture of catalytic layers for electrodes in electrochemical cells, particularly fuel cells

Claim 1

METHOD FOR THE MANUFACTURE OF POROUS CATALYTIC LAYERS FOR ELECTRODES IN ELECTROCHEMICAL CELLS, ESPECIALLY FUEL CELLS, FROM CATALYST POWDER OF DIFFERENT GRAIN SIZES WHICH COMPRISES MOVING A PLANAR SUBSTRATE GENERALLY ALONG A PREDETERMINED AND GENERALLY STRAIGHT LINE PATH, AERATING SAID CATALYST POWDER OF DIFFERENT GRAIN SIZES WITH A GAS STREAM, ACCELERATING AND DIRECTING A STREAM OF CATALYST POWDER INITIALLY IN A DIRECTION SUBSTANTIALLY PARALLEL TO SAID STRAIGHT LINE PATH AND DISPOSED ABOVE SAID DIFFERENT SIZE AND WEIGHT ARE CARRIED A DIFFERENT DISTANCE, AND UTILIZING THE EFFECT OF GRAVITY TO CAUSE SAID STREAM OF CATALYST POWDER TO FALL BY GRAVITY ONTO SAID MOVING SUBSTRATE THEREBY TO FORM A PLANAR LAYER ON THE SUBSTRATE WITH GRADATION OF THE CATALYST POWDER FORMING THE PLANAR LAYER BY GRAIN SIZE AND IN WHICH THE PORE STRUCTURE OF SAID PLANAR LAYER HAS PORE SIZE CHANGES WITH SMALLER PORES WITH THE SMALLER GRAIN PARTICLES AND WITH THE PORE SIZES INCREASING WITH THE LARGER SIZE PARTICLES.