Patent ID: 8574790
Filing Date: 2013-11-05
Classification: H01M,Y02E,Y02P

Abstract:
1. A method of making a graded electrode, the method comprising: depositing a first electrode ink on a substrate to form a first electrode layer having a first ionomer to carbon ratio, wherein the substrate is a gas diffusion media or a polymer electrolyte membrane; passing the substrate with the first electrode layer under a first blade having a first height at one end applied adjacent to a first side of the substrate and a second height at an opposite end applied adjacent to a second side of the substrate across from the first side, the first height of the first blade being less than the second height of the first blade, to remove a portion of the first electrode layer such that the thickness of the first electrode layer increases across the width of the substrate from the first side of the substrate to the second side of the substrate; depositing a second electrode ink adjacent to the first electrode layer to form a second electrode layer having a second ionomer to carbon ratio different from the first ionomer to carbon ratio; and passing the substrate with the first and second electrode layers under a second blade having a first height at one end applied adjacent to the first side of the substrate and a second height at an opposite end applied adjacent to the second side of the substrate, the first height of the second blade being greater than the second height of the second blade, to remove a portion of the second layer such that the thickness of the second electrode layer decreases across the width of the substrate from the first side of the substrate to the second side of the substrate, a combined electrode layer formed from the first electrode layer and the second electrode layer having an average ionomer to carbon ratio that varies across the width of the substrate from the first side to the second side.