US 9,812,725 B2
Proton-conducting membrane and use thereof
Brian Benicewicz, Loudonville, NY (US); Sigmar Bräuninger, Hemsback (DE); Gordon Calundann, Somerset, NJ (US); and Guoqing Qian, Irmo, SC (US)
Assigned to BASF SE, (DE)
Filed by BASF SE, Ludwigshafen (DE)
Filed on Jan. 16, 2013, as Appl. No. 13/742,774.
Claims priority of provisional application 61/587,138, filed on Jan. 17, 2012.
Prior Publication US 2013/0183602 A1, Jul. 18, 2013
Int. Cl. H01M 8/103 (2016.01); C08J 5/22 (2006.01); H01M 8/1069 (2016.01); H01M 8/1086 (2016.01)
CPC H01M 8/103 (2013.01) [C08J 5/22 (2013.01); H01M 8/1069 (2013.01); H01M 8/1086 (2013.01); Y02P 70/56 (2015.11)] 24 Claims
 
1. A proton-conducting polymer membrane based on polyazoles, obtainable by a process comprising steps of
A) providing a monomer solution and/or dispersion including
(i) one or more aromatic tetraamino compounds and
either (ii) one or more aromatic carboxylic acids or esters thereof which contain at least two acid groups per carboxylic acid monomer,
or (iii) one or more aromatic and/or heteroaromatic diaminocarboxylic acids, in polyphosphoric acid to form a solution and/or dispersion
B) heating the monomer solution and/or dispersion from step A), and polymerizing until a formed polyazole polymer having an intrinsic viscosity of at least 0.8 dl/g is obtained,
C) adding of one or more polyazole polymer to the polyphosphoric acid and the formed polyazole polymer of step B), the added one or more polyazole polymer being different from the formed polyazole polymer of step B),
D) heating the mixture from step C),
E) applying a membrane layer using the mixture heated according to step D) on a carrier,
G) treating the membrane layer formed in the presence of water and/or moisture to provide a membrane including at least a formed polyazole and an added polyazole being different from the formed polyazole, and
H) removing the membrane from the carrier;
wherein a total content of all polyazole polymers in the membrane is at least 10% by weight and up to about 25% by weight and said total content includes any acids and water being present, said total content excluding however any optional additives and wherein the membrane has a Young Modulus of at least 4.5 MPa, and
wherein the monomers in the monomer solution and/or dispersion of step A accounts for less than 10% by weight of the total solid content of all polyazole polymers in the membrane.
 
22. An electrode having a proton-conducting polymer membrane coating based on polyazoles, obtainable by a process comprising the steps of
A) providing a monomer solution and/or dispersion including
(i) one or more aromatic tetraamino compounds and
either (ii) one or more aromatic carboxylic acids or esters thereof which contain at least two acid groups per carboxylic acid monomer,
or (iii) one or more aromatic and/or heteroaromatic diaminocarboxylic acids,
in polyphosphoric acid,
B) heating the monomer solution and/or dispersion from step A), preferably under inert gas, and polymerizing until a formed polyazole polymer having an intrinsic viscosity of at least 0.8 dl/g is obtained,
C) adding one or more polyazole polymer to the polyphosphoric acid and the polymer formed in step B, the added one or more polyazole polymer being different from the formed polyazole polymer of step B),
D) heating the mixture from step C),
E) applying a membrane layer using the mixture heated according to step D) on an electrode,
F) optionally heating the membrane layer on the electrode obtained from step E), and
G) treating the membrane layer formed in step E) or optionally step F) in the presence of water and/or moisture to provide on the electrode a membrane including at least a formed polyazole and an added polyazole being different from the formed polyazole,
wherein a total solid content of all polyazole polymers in the membrane is at least 10% by weight and up to about 25% by weight and said total content includes any acids and water being present, said total content excluding any optional additives, and wherein the membrane has a Young Modulus of at least 4.5 MPa, and
wherein the monomers in the monomer solution and/or dispersion of step A accounts for less than 10% by weight of the total solid content of all polyazole polymers in the membrane.