Composite electrolyte with crosslinking agents

• US 20050282053A1
• Filed: 07/28/2005
• Published: 12/22/2005
• Est. Priority Date: 08/28/2003
• Status: Abandoned Application

• Current Assignee: Arunachala Nadar Mada Kannan, Gangadhar Panambur, Karl Milton Iii Taft, Matthew Robert Kurano
• Original Assignee: Arunachala Nadar Mada Kannan, Gangadhar Panambur, Karl Milton Iii Taft, Matthew Robert Kurano
• Inventors: Taft, Karl Milton III, Kurano, Matthew Robert, Panambur, Gangadhar, Mada Kannan, Arunachala Nadar
• Application Number:
  US11/192,822
• Publication Number:
  US 20050282053A1
• Time in Patent Office: Days
• US Class Current: 429/483
• CPC Class Codes: C08G 65/4056 (I) or (II) containing sulfur as the sulfone group C08G75/23
• CPC Class Codes: C08G 65/48 Polymers modified by chemical after-treatment
• CPC Class Codes: C08G 75/24 Polysulfonates
• CPC Class Codes: C08J 5/2218 Synthetic macromolecular compounds
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 2300/0091 in the form of mixtures
• CPC Class Codes: H01M 8/1004 characterised by membrane-electrode assemblies [MEA] H01M8/12 takes precedence
• CPC Class Codes: H01M 8/1023 having only carbon, e.g. polyarylenes, polystyrenes or polybutadiene-styrenes
• CPC Class Codes: H01M 8/1025 having only carbon and oxygen, e.g. polyethers, sulfonated polyetheretherketones [S-PEEK], sulfonated polysaccharides, sulfonated celluloses or sulfonated polyesters
• CPC Class Codes: H01M 8/1027 having carbon, oxygen and other atoms, e.g. sulfonated polyethersulfones [S-PES]
• CPC Class Codes: H01M 8/1032 having sulfur, e.g. sulfonated-polyethersulfones [S-PES]
• CPC Class Codes: H01M 8/1039 halogenated, e.g. sulfonated polyvinylidene fluorides
• CPC Class Codes: H01M 8/1051 Non-ion-conducting additives, e.g. stabilisers, SiO2 or ZrO2
• CPC Class Codes: H01M 8/1072 by chemical reactions, e.g. insitu polymerisation or insitu crosslinking
• CPC Class Codes: H01M 8/1081 starting from solutions, dispersions or slurries exclusively of polymers
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A covalent crosslinking of ion-conducting materials via sulfonic acid groups can be applied to various low cost electrolyte membrane base materials for improved fuel cell performance metrics relative to such base material. This proposed approach is due, in part, to the observation that many aromatic and aliphatic polymer materials have significant potential as proton exchange membranes if a modification can increase their physical and chemical stabilities without sacrificing electrochemical performance or significantly increasing the material and production costs.

Claims

1. A fuel cell, comprising:

an anode;

a cathode

fuel supply to the anode;

oxidant supply to the cathode;

a polymer electrolyte membrane positioned between the cathode and anode and fashioned with crosslinking agent crosslinked into an ion-conducting base material through hydroxyl and sulfonic acid condensation or though amine and sulfonic acid condensation; and

a membrane electrode assembly (MEA) with the polymer electrolyte membrane.

2. A method of fabricating a polymer membrane suitable for use in an electrochemical fuel cell, comprising:

synthesizing a polymer material of viscous nature which contains

(a) crosslinked polymer chains,

(b) a solvent for dissolving the polymer chains, and

(c) any quantity of inorganic additives,

spreading the synthesized polymer material to form a uniform thickness layer on a substrate;

allowing the solvent to evaporate under controlled atmosphere from the synthesized polymer material to yield the polymer electrolyte membrane; and

preparing the polymer electrolyte membrane for use in a fuel cell by protonation and purification.

3. A material with tailorable microstructure, comprising:

ion conducting base material that is sulfonated; and

a crosslinking agent that is hydroxyl terminated and is crosslinked to the sulfonated ion conducting base material via direct covalent crosslinking characterized by

HO—

R₁—

OH+2(HSO₃)—

R₂→

R₂—

SO₂—

O—

R₁—

O—

SO₂—

R₂+2H₂O

where R₁ is the hydroxyl terminated crosslinking agent'"'"'s main chain and R₂ is the sulfonated ion conducting base material.

4. A material as in claim 3, wherein the ion conducting base material includes an inorganic cation exchange material

5. A material as in claim 4, wherein the inorganic cation exchange material is selected from a group consisting of clay, zeolite, hydrous oxide, and inorganic salt.

6. A material as in claim 4, wherein the inorganic cation exchange material further includes a silica based material and a proton conducting polymer based material.

7. A material as in claim 3, wherein the main chain includes one or more chains selected from a group consisting of an aromatic polymer chain, an aliphatic polymer chain, organic molecules and inorganic molecules.

8. A material as in claim 3, wherein the sulfonated ion conducting base material includes, one or more chains selected from a group consisting of an aromatic polymer chain, an aliphatic polymer chain, organic molecules and inorganic molecules.

9. A material with tailorable microstructure, comprising:

ion conducting base material that is sulfonated; and

a crosslinking agent that is amine terminated and is crosslinked to the sulfonated ion conducting base material via direct covalent crosslinking characterized by

H₂N—

R₁—

N—

H₂+2(HSO₃)—

R₂→

R₂—

SO₂—

NH—

R₁—

NH—

SO₂—

R₂+2H₂O

where R₁ is the amine terminated crosslinking agent'"'"'s main chain and R₂ is the sulfonated ion conducting base material.

10. A material as in claim 9, wherein the ion conducting base material includes an inorganic cation exchange material

11. A material as in claim 10, wherein the inorganic cation exchange material is selected from a group consisting of clay, zeolite, hydrous oxide, and inorganic salt.

12. A material as in claim 10, wherein the inorganic cation exchange material further includes a silica based material and a proton conducting polymer based material.

13. A material as in claim 9, wherein the main chain includes one or more chains selected from a group consisting of an aromatic polymer chain, an aliphatic polymer chain, organic molecules and inorganic molecules.

14. A material as in claim 9, wherein the sulfonated ion conducting base material includes, one or more chains selected from a group consisting of an aromatic polymer chain, an aliphatic polymer chain, organic molecules and inorganic molecules.

15. A material with tailorable microstructure, comprising:

ion conducting base material that is amine or hydroxyl terminated; and

a crosslinking agent that is sulfonic acid terminated and is crosslinked to the amine or hydroxyl terminated ion conducting base material via direct covalent crosslinking characterized by, respectively,

HO₃S—

R₃—

SO₃H+2(HO)—

R₄→

R₄—

SO₂—

O—

R₃—

O—

SO₂—

R₄+2H₂O
or
HO₃S—

R₃—

SO₃H+2(H₂N)—

R₄→

R₄—

SO₂—

NH—

R₃—

NH—

SO₂—

R₄+2H₂O

where R₃ is the sulfonic acid terminated crosslinking agent'"'"'s main and R₄ is the amine or hydroxyl terminated ion conducting base.

16. A material as in claim 15, wherein the ion conducting base material includes an inorganic cation exchange material

17. A material as in claim 16, wherein the inorganic cation exchange material is selected from a group consisting of clay, zeolite, hydrous oxide, and inorganic salt.

18. A material as in claim 16, wherein the inorganic cation exchange material further includes a silica based material and a proton conducting polymer based material.

19. A material as in claim 15, wherein the main chain includes one or more chains selected from a group consisting of an aromatic polymer chain, an aliphatic polymer chain, organic molecules and inorganic molecules.

20. A material as in claim 15, wherein the sulfonated ion conducting base material includes, one or more chains selected from a group consisting of an aromatic polymer chain, an aliphatic polymer chain, organic molecules and inorganic molecules.