Multiple layer membranes for fuel cells employing direct feed fuels
AssigneeE.I. du Pont de Nemours and Company
InventorGovindarajulu Rajendran
Life of this patent
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AssigneeE.I. du Pont de Nemours and Company
InventorGovindarajulu Rajendran
Estimating the term…
A cation exchange membrane having a laminated structure of at least three layers of cation exchange polymer. In a membrane in accordance with the invention, the cation exchange polymer in the laminate has a polymer backbone and cation exchange groups carried on recurring side chains attached to the polymer backbone with the number of carbon atoms in the polymer backbone in relation to the cation exchange groups defining an ion exchange ratio (IXR) for each layer. The layers have differing IXR values which provide one or more high IXR layers and one or more low IXR layers with the IXR of the low IXR layers being less than about 17 and the IXR of the high IXR layers being at least about 15. In a membrane in accordance with the invention, the high and low layers further provide a change in IXR of at least about 2 in at least two locations across the thickness of the membrane.
A cation exchange membrane comprising a laminated structure of at least three layers of cation exchange polymer having a polymer backbone and cation exchange groups carried on recurring side chains attached to said polymer backbone with the number of carbon atoms in said polymer backbone in relation to said cation exchange groups defining an ion exchange ratio (IXR) for each layer, said layers having differing IXR values which define one or more high IXR layers and one or more low IXR layers, the IXR of said high IXR layers being higher than the IXR of said low layers, said IXR of said low IXR layers being less than about 17 and said IXR of said high IXR layers being at least about 15, said high and low layers further providing a change in IXR of at least about 2 in at least two locations across the thickness of the membrane.
A fuel cell comprising an anode compartment a cathode compartment and a cation exchange membrane serving as a separator and electrolyte between said anode and cathode compartments, said membrane having an electrode in contact with at least one of its surfaces, said membrane comprising a laminated structure of at least three layers of cation exchange polymer having a polymer backbone and cation exchange groups carried on recurring side chains attached to said polymer backbone with the number of carbon atoms in said polymer backbone in relation to said cation exchange groups defining an ion exchange ratio (IXR) for each layer, said layers having differing IXR values which define one or more high IXR layers and one or more low IXR layers, the IXR of said high IXR layers being higher than the IXR of said low layers, said IXR of said low IXR layers being less than about 17 and said IXR of said high IXR layers being at least about 15, said high and low layers further providing a change in IXR of at least about 2 in at least two locations across the thickness of the membrane.
Dependencies are inferred from the claim text.