# US 11,444,305 B2 · Polymer electrolyte membrane, method for manufacturing same, and membrane electrode assembly comprising same

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- Number: US 11,444,305 B2
- Document ID: US11444305B2
- Status: Granted
- Kind: B2
- Application number: 16/646,271
- Filed: 2018-09-27
- Published: 2020-09-10
- Granted: 2022-09-13
- Earliest claimed: 2017-09-29
- Applicants: Kolon Industries, Inc.
- Inventors: Dong-Hoon Lee; Na-Young Kim; Jung-Hwa Park; Eun-Su Lee
- Web page: https://patentgrep.com/patent/US11444305B2

## CPC

- H01M 8/1053: consisting of layers of polymers with at least one layer being ionically conductive
- B01D 69/106: {Membranes in the pores of a support, e.g. polymerized in the pores or voids}
- B01J 43/00: Amphoteric ion-exchange, i.e. using ion-exchangers having cationic and anionic groups; Use of material as amphoteric ion-exchangers; Treatment of material for improving their amphoteric ion-exchange properties (ion-exchange chromatography processes B01D15/36)
- B01J 47/12: characterised by the use of ion-exchange material in the form of ribbons, filaments, fibres or sheets, e.g. membranes (electrodialysis or electro-osmosis B01D61/42)
- C08J 5/005: {Reinforced macromolecular compounds with nanosized materials, e.g. nanoparticles, nanofibres, nanotubes, nanowires, nanorods or nanolayered materials}
- C08J 5/2262: {containing fluorine}
- C08J 5/2281: {fluorine containing heterogeneous membranes}
- C08J 5/2293: {After-treatment of fluorine-containing membranes}
- C08J 5/246: {using polymer based synthetic fibres}
- C08J 9/42: with macromolecular compounds
- H01M 8/1004: characterised by membrane-electrode assemblies [MEA] (H01M8/12 takes precedence)
- H01M 8/1023: having only carbon, e.g. polyarylenes, polystyrenes or polybutadiene-styrenes
- H01M 8/1027: having carbon, oxygen and other atoms, e.g. sulfonated polyethersulfones [S-PES]
- H01M 8/1039: halogenated, e.g. sulfonated polyvinylidene fluorides
- H01M 8/1051: Non-ion-conducting additives, e.g. stabilisers, SiO2 or ZrO2
- H01M 8/1058: characterised by a porous support having no ion-conducting properties
- H01M 8/1067: characterised by their physical properties, e.g. porosity, ionic conductivity or thickness
- H01M 8/1069: characterised by the manufacturing processes
- C08J 2327/12: containing fluorine atoms
- C08J 2365/02: Polyphenylenes
- C08J 2371/12: Polyphenylene oxides
- C08J 2379/08: Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- C08J 2427/12: containing fluorine atoms
- C08J 2471/12: Polyphenylene oxides
- C08J 2479/08: Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- H01M 2008/1095: {Fuel cells with polymeric electrolytes}
- H01M 2220/20: Batteries in motive systems, e.g. vehicle, ship, plane
- H01M 2300/0082: Organic polymers
- H01M 2300/0094: in the form of layered products, e.g. coatings
- Y02E 60/10: Energy storage using batteries
- Y02E 60/50: Fuel cells
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

Disclosed are a polymer electrolyte membrane, a method of manufacturing the membrane, and a membrane-electrode assembly including the membrane. The polymer electrolyte membrane contains a porous support having a plurality of pores, a first layer including a first ion conductor that fills the pores adjoining one surface of the porous support, and a second layer including a second ion conductor that fills the pores adjoining the other surface of the porous support, wherein the first ion conductor and the second ion conductor are different from each other, and one selected from the group consisting of the first layer, the second layer, and a combination thereof includes an organic-based antioxidant.

## Claims

### Claim 1

A polymer electrolyte membrane comprising:
a porous support having first and second surfaces opposite to each other, the porous support including a first portion having the first surface and a second portion having the second surface;
a first layer formed by filling first pores in the first portion of the porous support with a first ion conductor;
a second layer formed by filling second pores in the second portion of the porous support with a second ion conductor;
a first ion conductor layer on the first surface of the porous support, the first ion conductor layer comprising the first ion conductor; and
a second ion conductor on the second surface of the porous support, the second ion conductor layer comprising the second ion conductor,
wherein,
the first ion conductor has a lower equivalent weight (EW) than the second ion conductor,
a ratio of first thickness to second thickness is 9:1 to 6:4, the first thickness being a sum of a thickness of the first layer and a thickness of the first ion conductor layer, the second thickness being a sum of a thickness of the second layer and a thickness of the second ion conductor layer, and
one selected from a group consisting of the first layer, the second layer, and a combination thereof includes an antioxidant.

### Claim 2 (depends on 1)

The polymer electrolyte membrane according to claim 1, wherein a weight per unit volume of the antioxidant in the first layer and a weight per unit volume of the antioxidant in the second layer are different from each other.

### Claim 3 (depends on 2)

The polymer electrolyte membrane according to claim 2, wherein
the weight per unit volume of the antioxidant in one of the first and second layers which has larger weight per unit volume of the antioxidant than the other ranges from 30 mg/cm3 to 4,000 mg/cm3, and
the weight per unit volume of the antioxidant in the other of the first and second layers ranges from 10 mg/cm3 to 2,000 mg/cm3.

### Claim 4 (depends on 1)

The polymer electrolyte membrane according to claim 1, wherein
the antioxidant is also included in the first and second ion conductor layers,
a weight per unit volume of the antioxidant in the first ion conductor layer is greater than a weight per unit volume of the antioxidant in the first layer, and
a weight per unit volume of the antioxidant in the second ion conductor layer is greater than a weight per unit volume of the antioxidant in the second layer.

### Claim 5 (depends on 1)

The polymer electrolyte membrane according to claim 1, wherein
the antioxidant is also included in the first and second ion conductor layers,
a weight per unit volume of the antioxidant decreases or increases in an order of the first ion conductor layer, the first layer, the second layer, and the second ion conductor layer, so that the polymer electrolyte membrane has a concentration gradient of the antioxidant.

### Claim 6

The polymer electrolyte membrane, wherein
one of the first and second layers includes an organic-based antioxidant, and
the other of the first and second layers does not include any antioxidant or includes a metal-based antioxidant.

### Claim 7 (depends on 6)

The polymer electrolyte membrane according to claim 6, wherein the metal-based antioxidant is one capable of decomposing a peroxide or radical, which is selected from a group consisting of a transition metal, a noble metal, an ion thereof, a salt thereof, an oxide thereof, and a mixture thereof.

### Claim 8

The polymer electrolyte membrane, wherein one selected from a group consisting of the first layer, the second layer, and a combination thereof includes an organic-based antioxidant selected from a group consisting of syringic acid, vanillic acid, protocatechuic acid, coumaric acid, caffeic acid, ferulic acid, chlorogenic acid, cynarine, gallic acid, and a mixture thereof.

### Claim 9

The polymer electrolyte membrane, wherein
each of the first ion conductor and the second ion conductor is a fluorinated polymer comprising a fluorinated carbon backbone and a side chain represented by Chemical Formula 1 below, and
the first ion conductor and the second ion conductor have different side-chain lengths,
[Chemical Formula 1]
—(OCF2CFRf)a—O—(CF2)b—X
in Chemical Formula 1 above,
Rf is respectively and independently one selected from a group consisting of F, Cl, and a perfluorinated alkyl group having a carbon number ranging from 1 to 10,
X is an ion-exchanging group,
a is a real number ranging from 0 to 3, and
b is a real number ranging from 1 to 5.

### Claim 10 (depends on 1)

The polymer electrolyte membrane according to claim 1, wherein
each of the first ion conductor and the second ion conductor is a polymer comprising a hydrophilic repeating unit and a hydrophobic repeating unit, and
the first ion conductor and the second ion conductor have different molar ratios of the hydrophilic repeating unit to the hydrophobic repeating unit.

### Claim 11 (depends on 10)

The polymer electrolyte membrane according to claim 10, wherein the molar ratio of the hydrophilic repeating unit to the hydrophobic repeating unit of the first ion conductor is higher than the molar ratio of the hydrophilic repeating unit to the hydrophobic repeating unit of the second ion conductor.

### Claim 12 (depends on 1)

A membrane-electrode assembly comprising:
an anode;
a cathode; and
the polymer electrolyte membrane according to claim 1, the polymer electrolyte membrane being disposed between the anode and the cathode.

### Claim 13 (depends on 12)

A fuel cell comprising the membrane-electrode assembly according to claim 12.

### Claim 14

A method of manufacturing a polymer electrolyte membrane, the method comprising:
preparing a porous support having first and second surfaces opposite to each other, the porous support including a first portion having the first surface and a second portion having the second surface;
filling first pores in the first region of the porous support with a first ion conductor to form a first layer;
forming a first ion conductor layer on the first surface of the porous support with the first ion conductor;
filling second pores in the second region of the porous support with a second ion conductor to form a second layer; and
forming a second ion conductor layer on the second surface of the porous support with the second ion conductor, wherein
the first ion conductor has a lower equivalent weight (EW) than the second ion conductor,
a ratio of first thickness to second thickness is 9:1 to 6:4, the first thickness being a sum of a thickness of the first layer and a thickness of the first ion conductor layer, the second thickness being a sum of a thickness of the second layer and a thickness of the second ion conductor layer, and
one selected from a group consisting of the first layer, the second layer, and a combination thereof includes an antioxidant.