Split architectures for MEA durability
View Patent ↗A membrane electrode assembly including an ionically conductive member, an electrode, and an electrically conductive member including an active layer, wherein the electrode is a smooth, continuous layer that completely covers and supports the ionically conductive member. The electrode and active layer further include a first and second catalyst content, respectively; and 50% of the total catalyst content is present in the electrode and 50% of the total catalyst content is present in the active layer.
1. An assembly for a fuel cell comprising:
an ionically conductive membrane having a major surface;
an electrically conductive member facing said membrane major surface and having an active layer, said active layer having an active layer catalyst content; and
an electrode between said ionically conductive membrane and said electrically conductive member, said electrode having a major surface at said membrane major surface, and said electrode having an electrode catalyst content,
wherein said electrode has a peripheral extent substantially the same as the membrane and wherein said electrode further comprises a central region and a peripheral region, said central region having a first group of catalyzed particles dispersed in a binder, said peripheral region having a second group of particles dispersed in a binder that are catalyzed or uncatalyzed, said peripheral region overlapping a peripheral extent of said active layer, and said central region being within said peripheral extent of said active layer;
wherein said peripheral region is electrically non-conductive.
2. An assembly for a fuel cell comprising:
an ionically conductive membrane having a major surface;
an electrically conductive member facing said membrane major surface and having an active layer, said active layer having an active layer catalyst content; and
an electrode between said ionically conductive membrane and said electrically conductive member, said electrode having a major surface at said membrane major surface, and said electrode having an electrode catalyst content,
wherein said electrode has a peripheral extent substantially the same as the membrane and wherein said electrode further comprises a central region and a peripheral region, said central region having a first group of catalyzed particles dispersed in a binder, said peripheral region having a second group of particles dispersed in a binder that are catalyzed or uncatalyzed, said peripheral region overlapping a peripheral extent of said active layer, and said central region being within said peripheral extent of said active layer;
wherein the first group of particles is dispersed in an ionically conductive binder, and said second group of particles is dispersed in an ionically non-conductive binder.
3. A membrane electrode assembly comprising:
an ionically conductive membrane having a major surface;
an electrode at said major surface, said electrode defining a continuous layer supporting said membrane; and
an electrically conductive member adjacent said electrode and including an active layer;
wherein at least one of said electrode and said active layer comprise a central region and a peripheral region;
a gradient of electrochemically active material exists between said central region and said peripheral region such that a content of said electrochemically active material is greater in said central region than said peripheral region,
wherein said peripheral region is separate and distinct from a sealing member.
4. The membrane electrode assembly according to claim 3 , wherein said central region includes a first group of particles that are electrically conductive, and said peripheral region includes a second group of particles that are electrically non-conductive.
5. The membrane electrode assembly according to claim 3 , wherein said electrode provides structural support to said membrane and thereby restricts movement of said membrane.
6. The assembly according to claim 3 , wherein said central region comprises an ionically conductive binder retaining electrically conductive particles and an active material.
7. The assembly according to claim 3 , wherein said peripheral region comprises an ionically non-conductive binder retaining said electrically non-conductive particles and said active material.
8. The assembly according to claim 3 , wherein said peripheral region further comprises thermally conductive material.
9. The assembly according to claim 7 , wherein said ionically non-conductive binder is a thermoplastic resin.
10. The assembly according to claim 3 , wherein said electrode and said active layer further comprise a first catalyst content and a second catalyst content, respectively; and
said first catalyst content includes 50% of the total catalyst content of the assembly, and said second catalyst content includes 50% of the total catalyst content of the assembly.
11. The assembly according to claim 3 , wherein said electrically conductive member further comprises an intermediate layer comprising carbon particles dispersed in a binder that couples said active layer and said electrically conductive member.
12. The assembly according to claim 11 , wherein said intermediate layer is a water management layer.