Hydrocarbon PEM Membranes with Perfluorosulfonic Acid Groups for Automotive Fuel Cells
A solid electrochemical cell membrane composition comprises a hydrocarbon polymeric main chain and a perfluorinated superacid side group. A method of producing the membrane composition is also disclosed.
1 . An electrochemical cell membrane composition comprising a hydrocarbon polymer main chain and a perfluorinated superacid side group covalently attached to said polymeric main chain.
2 . A fuel cell comprising a membrane composition as set forth in claim 1 .
3 . An electrochemical cell membrane composition of claim 1 , wherein the perfluorinated superacid is present in the composition at 0.1 to 2.84 meq/g of membrane composition.
4 . An electrochemical cell membrane composition of claim 1 , wherein the hydrocarbon polymeric main chain comprises at least one of polyolefins, polystyrene, polyisoprene, polybutadiene, polyvinylchloride, polyvinylfluoride, polyvinylidene fluoride, polyacrylates, polymethacrylates, polychloroprene, polyacrylonitrile, or copolymers thereof.
5 . An electrochemical cell membrane composition of claim 1 , wherein the superacid has the following chemical formula: —R f —SO n X; where R f is a perfluorinated radical, n is number 2 or 3, and X is an element selected from the group consisting of hydrogen, fluorine, chlorine, sodium, potassium, lithium, magnesium, and the combination thereof.
6 . An electrochemical cell membrane composition of claim 5 , wherein the perfluorinated radical comprises a perfluorinated olefin, a perfluoroether, or the combination thereof.
7 . An electrochemical cell membrane composition of claim 1 comprising a product of a chemical reaction between the hydrocarbon polymer and the reactive compound having the perfluorinated superacid group.
8 . An electrochemical cell membrane composition of claim 7 , wherein the chemical reaction is a coupling reaction or a graft polymerization reaction.
9 . An electrochemical cell membrane composition of claim 8 , wherein the coupling reaction is an addition, displacement, radical coupling or condensation reaction.
10 . An electrochemical cell membrane composition of claim 9 , wherein the graft polymerization reaction is a free radical initiated polymerization.
11 . An electrochemical cell membrane composition of claim 7 , wherein the hydrocarbon polymer comprises at least one of polyolefins, polystyrene, polyisoprene, polybutadiene, polyvinylchloride, polyvinylfluoride, polyvinylidene fluoride, polyacrylates, polymethacrylates, polychloroprene, polyacrylonitrile, or copolymers thereof.
12 . An electrochemical cell membrane composition of claim 7 , wherein said reactive compound has a chemical structure represented by the formula:
Z—R f —SO n X,
where Z is a reactive radical capable of reacting and chemically attaching to said hydrocarbon polymer, R f is a perfluorinated radical, n is number 2 or 3, and X is an element selected from the group consisting of hydrogen, fluorine, chlorine, sodium, potassium, lithium, magnesium, and the combination thereof.
13 . An electrochemical cell membrane composition of claim 12 , wherein Z is a halogen, a fluorinated vinyl group, or an iodine radical.
14 . An electrochemical cell membrane composition of claim 12 , wherein X is hydrogen, fluorine or chlorine.
15 . An electrochemical cell membrane composition of claim 14 , wherein n is 2 and X is fluorine.
16 . A fuel cell comprising:
an anode;
a cathode; and
a membrane between said anode and cathode;
wherein the membrane comprises a polymer having a hydrocarbon polymeric main chain and a perfluorinated superacid side group covalently attached to said polymeric main chain.
17 . A fuel cell of claim 16 , wherein the superacid is present at about 0.1 to 2.84 meq/g of polymer.
18 . A fuel cell of claim 17 , wherein the superacid has a chemical structure represented by the formula: —R f —SO n X; where R f is a perfluorinated radical, n is number 2 or 3, and X is an element selected from the group consisting of hydrogen, fluorine, chlorine, sodium, potassium, lithium, magnesium, and the combination thereof.
19 . A fuel cell of claim 18 , wherein the operating temperature of the fuel cell is at least 120° C. and the hydration level of said membrane is more than 0.6 millimoles of super-acid groups per gram of membrane.
20 . A method of producing a fuel cell membrane composition comprising:
providing a hydrocarbon polymer;
providing a perfluorinated superacid compound having a reactive group; and
contacting or mixing the hydrocarbon polymer with the perfluorinated superacid compound to cause a coupling reaction or a graft polymerization that results in covalent attachment of the perfluorinated superacid to the hydrocarbon polymer.