Membrane with Laminated Structure and Orientation Controlled Nanofiber Reinforcement Additives for Fuel Cells
An ion-conducting membrane for fuel cell applications a first layer including a first ion-conducting polymer and nanofibers dispersed therein. The first layer includes a first side and a second side. A second layer is disposed over the first side of the first layer and includes a second ion-conducting polymer without nanofibers.
1 . An ion-conducting membrane for a fuel cell, the ion-conducting membrane comprising:
a first layer including a first ion-conducting polymer and nanofibers, the nanofibers being dispersed within the first ion-conducting polymer, the first layer including a first side and a second side;
a second layer disposed over the first side of the first layer including a second ion-conducting polymer without nanofibers.
2 . The ion-conducting membrane of claim 1 wherein the first ion-conducting polymer and the second ion-conducting polymer each independently comprise a component selected from the group consisting of perfluorosulfonic acid polymer, hydrocarbon based ionomer, sulfonated polyether ether ketone polymer, perfluorocyclobutane polymers, and combinations thereof.
3 . The ion-conducting membrane of claim 1 wherein the nanofibers are polymeric nanofibers or inorganic nanofibers.
4 . The ion-conducting membrane of claim 1 wherein the nanofibers comprise a component selected from the group consisting of polyvinylidene fluoride, polyester, and combinations thereof.
5 . The ion-conducting membrane of claim 1 wherein the nanofibers comprise a component selected from the group consisting of carbon, metal, ceramic oxide/composites, CeO 2 , MnO 2 , TiO 2 , ZrO 2 , SiO 2 , Al 2 O 2 , ZrCeO 2 , and combinations thereof.
6 . The ion-conducting membrane of claim 1 wherein the nanofibers have a continuous web configuration.
7 . The ion-conducting membrane of claim 1 wherein the nanofibers comprise discrete individual fibers.
8 . The ion-conducting membrane of claim 1 wherein the nanofibers are electrically conductive or electrically non-conductive.
9 . The ion-conducting membrane of claim 1 wherein the nanofibers have an average length greater than about 10 nm and an average diameter from about 5 nm to about 10 μm.
10 . The ion-conducting membrane of claim 1 wherein the first layer includes nanofibers in an amount from about 1 to about 50 weight percent of the total weight of the first layer.
11 . The ion-conducting membrane of claim 1 wherein the nanofibers have an in-plane oriention.
12 . The ion-conducting membrane of claim 1 wherein the first layer has moisture-induced swelling less than about 10 percent.
13 . The ion-conducting membrane of claim 1 further comprising a third layer disposed over and contacting the second side of the first layer, the third layer including a third ion-conducting polymer without nanofibers.
14 . The ion-conducting membrane of claim 1 further comprising a third layer disposed over and contacting the second layer, the third layer including a third ion-conducting polymer and nanofibers, the nanofibers being dispersed within the third ion-conducting polymer.
15 . A membrane electrode assembly for fuel cells, the membrane electrode assembly comprising:
an anode layer;
a cathode layer;
an ion-conducting membrane interposed between the anode layer and the cathode layer, the ion-conducting membrane comprising:
a first layer including a first ion-conducting polymer and nanofibers, the nanofibers being dispersed within the first ion-conducting polymer, the first layer including a first side and a second side;
a second layer disposed over the first side of the first layer including a second ion-conducting polymer without nanofibers.
16 . The membrane electrode assembly of claim 15 wherein the first ion-conducting polymer and the second ion-conducting polymer each independently comprise a component selected from the group consisting of perfluorosulfonic acid polymer, hydrocarbon based ionomer, sulfonated polyether ether ketone polymer, perfluorocyclobutane polymers, and combinations thereof.
17 . The membrane electrode assembly of claim 15 wherein the nanofibers are polymeric nanofibers or inorganic nanofibers.
18 . The ion-conducting membrane of claim 15 wherein the nanofibers comprise a component selected from the group consisting of polyvinylidene fluoride, polyester, and combinations thereof.
19 . The membrane electrode assembly of claim 15 wherein the nanofibers comprise a component selected from the group consisting of carbon, metal, ceramic oxide/composites, CeO 2 , MnO 2 , TiO 2 , ZrO 2 , SiO 2 , Al 2 O 2 , ZrCeO 2 , and combinations thereof.
20 . The membrane electrode assembly of claim 15 wherein the nanofibers have a continuous web configuration.
21 . The membrane electrode assembly of claim 15 wherein the nanofibers comprise discrete individual fibers.
22 . The membrane electrode assembly of claim 15 wherein the nanofibers are electrically conductive or electrically non-conductive.
23 . The membrane electrode assembly of claim 15 wherein the nanofibers have an average length greater than about 10 nm and an average diameter from about 5 nm to about 10 μm.
24 . The membrane electrode assembly of claim 15 wherein the first layer includes nanofibers in an amount from about 1 to about 50 weight percent of the total weight of the first layer.
25 . The membrane electrode assembly of claim 15 wherein the nanofibers have an in-plane orientation.
26 . The membrane electrode assembly of claim 15 further comprising a third layer disposed over and contacting the second side of the first layer, the third layer including a third ion-conducting polymer without nanofibers.
27 . The membrane electrode assembly of claim 15 further comprising a third layer disposed over and contacting the second layer, the third layer including a third ion-conducting polymer and nanofibers, the nanofibers being dispersed within the third ion-conducting polymer.