Method for producing a catalyst-coated membrane

1 . A method for producing a catalyst-coated membrane, comprising:

preparing and/or providing a first ink having a first ink composition, comprising substrated catalyst particles, proton-conducting ionomer and dispersing agent, in which an amount of the substrated catalyst particles in the first ink is less than an amount of the proton-conducting ionomer in the first ink;

preparing and/or providing at least one second ink having a second ink composition, comprising the substrated catalyst particles, the proton-conducting ionomer and the dispersing agent, in which an amount of the proton-conducting ionomer in the second ink is less than an amount of the substrated catalyst particles in the second ink;

unwinding a weblike proton-conducting membrane material provided on a roll;

applying at least one layer of the first ink with a first application tool onto at least one section of the weblike proton-conducting membrane material;

taking of the weblike proton-conducting membrane material, which is at least partially coated with the first ink, to an intermediate drying unit, and only partially drying the first ink via the intermediate drying unit to form a dry marginal film of the first ink at an outer marginal portion of the first ink facing away from the weblike proton-conducting membrane material before the second ink is applied while the remaining portion of the first ink remains wet;

applying at least one layer of the second ink with a second application tool onto an outermost side of the dry marginal film of the first ink which faces away from the weblike proton-conducting membrane material while the remaining portion of the first ink underlying the dry marginal film remains wet; and

taking of the weblike proton-conducting membrane material, which is at least partially coated with the first ink and the second ink to another drying unit, and fully drying the first ink along with fully drying the second ink such that no portion of the first ink and no portion of the second ink remains wet.

2 . The method according to claim 1 , wherein the first ink is applied with the first application tool on both of first and second sides of the weblike proton-conducting membrane material, and subsequently in time the second ink is applied with the second application tool on the first ink deposited on the first side of the weblike proton-conducting membrane material and on the first ink deposited on the second side of the weblike proton-conducting membrane material.

3 . The method according to claim 1 , wherein a layer thickness measurement is performed for the layer of the first ink after the depositing of the first ink.

4 . The method according to claim 3 , wherein the first ink is applied to subsequent sections of the membrane material in dependence on the measured layer thickness of preceding sections of the membrane material.

5 . The method according to claim 3 , wherein the second ink is deposited in dependence on the measured layer thickness of the first ink in order to limit an electrode thickness.

6 . The method according to claim 1 , wherein a layer thickness measurement of the electrode thickness is performed after applying the second ink, and the second ink is deposited on subsequent sections of the membrane material in dependence on a measured electrode thickness.

7 . The method according to claim 1 , wherein a catalyst particle charge of the weblike proton-conducting membrane material coated with the first and second inks is determined by an X-ray fluorescence analysis, and the amount of substrated catalyst particles in the first and second inks is adjusted as a function of a measured catalyst particle charge.

8 . The method according to claim 1 , wherein the weblike proton-conducting membrane material coated with the first and second inks is cut up into individual catalyst coated membranes.

9 . The method according to claim 1 , wherein a catalyst content is determined by a layer thickness measurement and/or by a charge measurement.