US 12,015,158 B2
Method for producing a catalyst-coated membrane
Frédéric Hasché, Hanau (DE); Markus Nesselberger, Hanau (DE); Nadia Kuwertz, Hanau (DE); Florian Eweiner, Hanau (DE); and Leonard Stoica, Hanau (DE)
Assigned to Heraeus Deutschland GmbH & Co. KG, Hanau (DE)
Appl. No. 17/624,725
Filed by Heraeus Deutschland Gmbh & Co. KG, Hanau (DE)
PCT Filed Apr. 29, 2020, PCT No. PCT/EP2020/061867
§ 371(c)(1), (2) Date Jan. 4, 2022,
PCT Pub. No. WO2021/001082, PCT Pub. Date Jan. 7, 2021.
Claims priority of application No. 19184400 (EP), filed on Jul. 4, 2019.
Prior Publication US 2022/0255086 A1, Aug. 11, 2022
Int. Cl. H01M 4/88 (2006.01); H01M 8/1004 (2016.01); H01M 8/1039 (2016.01); H01M 8/10 (2016.01)
CPC H01M 4/881 (2013.01) [H01M 4/8828 (2013.01); H01M 4/8882 (2013.01); H01M 8/1004 (2013.01); H01M 8/1039 (2013.01); H01M 2008/1095 (2013.01)] 11 Claims
 
1. A method for producing a membrane for a fuel or electrolytic cell, comprising:
(i) applying a liquid coating composition containing a supported precious metal-containing catalyst and an ionomer both to a front side and a back side of a polymer electrolyte membrane containing an ionomer, or a first liquid coating composition containing a supported precious metal-containing catalyst and an ionomer is applied only on a front side of a polymer electrolyte membrane containing an ionomer, and a second liquid coating composition containing a supported precious metal-containing catalyst and an ionomer is applied on a back side of the polymer electrolyte membrane, wherein the first and second liquid coating compositions are different, so that a coated polymer electrolyte membrane with a catalyst-containing layer on its front and back side is obtained, wherein the ionomer of the liquid coating composition and the ionomer of the polymer electrolyte membrane are each a copolymer which, as monomers, contain a fluoroethylene and a fluorovinyl ether containing a sulfonic acid group, wherein the fluorovinyl ether containing a sulfonic acid group has the formula (I):
—CF(OR)—CF2—  (I)
wherein
R has the following formula (II):
—(CF2—CF(CF3)—O)x(CF2)y—SO3H  (II)
where x=0-3 and y=1-5, and
(ii) thermally treating the coated polymer electrolyte membrane by heating it to a temperature in a range of 178° C. to 250° C. without exposure to external pressure.