Phosphonated polymers, and methods of production thereof, for use as polymer electrolyte membranes (PEMs) and/or catalyst ionomeric binders for electrodes in PEM fuel cells

Patent metadata

Field	Value
Publication number	US-11335932-B2
Application number	US-202016869885-A
Country	US
Kind code	B2
Filing date	May 8, 2020
Priority date	May 8, 2019
Publication date	May 17, 2022
Grant date	May 17, 2022

Abstract

The present disclosure provides phosphonated polymers that can be used, for example, as polymer electrolyte membranes (PEMs) and/or catalyst ionomeric binders for electrodes in PEM fuel cells, and more particularly for high-temperature PEM fuel cells. High-temperature PEM fuel cells that use phosphonated polymers of the present disclosure suffer from reduced or no acid leaching because, in at least some examples, phosphonic acid moieties are covalently bound to the backbone of the polymers. A phosphonated polymer include a backbone having one or more aromatic monomers, with each aromatic monomer having one or more phosphonic acid groups. A phosphonic acid group may include phosphonic acid or a functional group that is hydrolysable into phosphonic acid.

First claim

What is claimed is:

1. A phosphonated polymer for use as a polymer electrolyte membrane (PEM) and/or a catalyst ionomeric binder for one or more electrodes in a PEM fuel cell, comprising:
a backbone comprising at least one aromatic monomer; and
a functional group comprising a tetrafluorophenylphosphonic acid or a tetrafluorophenylphosphonate ester.

2. The phosphonated polymer of claim 1 , wherein the at least one aromatic monomer is selected from the group consisting of:

3. The phosphonated polymer of claim 2 , wherein:
R′ is individually selected to be hydrogen, fluorine, a methyl group (CH3), or an alkyl group ((CH2)mCH3), wherein m is an integer as low as 0 and as high as 10; and
X is either oxygen or sulfur.

4. A polymer electrolyte membrane (PEM) fuel cell comprising:
an anode;
a cathode; and
a PEM positioned between the anode and the cathode, the PEM comprising a phosphonated polymer, the phosphonated polymer comprising:
a backbone comprising at least one aromatic monomer; and
a functional group comprising a tetrafluorophenylphosphonic acid or a tetrafluorophenylphosphonate ester.

5. The PEM fuel cell of claim 4 , wherein the at least one aromatic monomer is selected from the group consisting of:

6. The PEM fuel cell of claim 5 , wherein:
R′ is individually selected to be hydrogen, fluorine, a methyl group (CH3), or an alkyl group ((CH2)mCH3), wherein m is an integer as low as 0 and as high as 10; and
X is either oxygen or sulfur.

7. A polymer electrolyte membrane (PEM) fuel cell comprising:
an anode;
a cathode;
a PEM positioned between the anode and the cathode; and
catalyst ionomeric binder corresponding to at least one of the anode or the cathode, the catalyst ionomeric binder comprising a phosphonated polymer, the phosphonated polymer comprising:
a backbone comprising at least one aromatic monomer; and
a functional group comprising a tetrafluorophenylphosphonic acid or a tetrafluorophenylphosphonate ester.

8. The PEM fuel cell of claim 7 , wherein the at least one aromatic monomer is selected from the group consisting of:

9. The PEM fuel cell of claim 8 , wherein:
R′ is individually selected to be hydrogen, fluorine, a methyl group (CH3), or an alkyl group ((CH2)mCH3), wherein m is an integer as low as 0 and as high as 10; and
X is either oxygen or sulfur.

10. The phosphonated polymer of claim 1 , wherein the backbone consists essentially of two or more adjacent aromatic groups, wherein the adjacent aromatic groups are directly bonded together by carbon-carbon bonds.

11. The PEM fuel cell of claim 4 , wherein the backbone consists essentially of two or more adjacent aromatic groups, wherein the two or more adjacent aromatic groups are directly bonded together by carbon-carbon bonds.

12. The PEM fuel cell of claim 7 , wherein the backbone consists essentially of two or more adjacent aromatic groups, wherein the two or more adjacent aromatic groups are directly bonded together by carbon-carbon bonds.

Assignees

• Triad Nat Security Llc

Inventors

• Park Eun Joo
• Kim Yu Seung

Classifications

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• C08G61/02

  Macromolecular compounds containing only carbon atoms in the main chain of the macromolecule, e.g. polyxylylenes · CPC title

• Y02E60/50

  Fuel cells · CPC title

• H01M8/1065 Primary

  characterised by the form, e.g. perforated or wave-shaped · CPC title

• C08G2261/312

  Non-condensed aromatic systems, e.g. benzene · CPC title