# US 9,005,841 B2 · Polymer electrolyte membrane for fuel cell, membrane electrode assembly and fuel cell including the same

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- Number: US 9,005,841 B2
- Document ID: US9005841B2
- Status: Granted
- Kind: B2
- Application number: 13/515,755
- Filed: 2010-12-17
- Published: 2013-09-05
- Granted: 2015-04-14
- Earliest claimed: 2009-12-18
- Assignees: LG Chem, Ltd.
- Applicants: Hyuk Kim; Seong Ho Choi; Kyung A Sung; SangWoo Lee; Tae Geun Noh; Ji Soo Kim
- Inventors: Hyuk Kim; Seong Ho Choi; Kyung A Sung; SangWoo Lee; Tae Geun Noh; Ji Soo Kim
- Web page: https://patentgrep.com/patent/US9005841B2

## CPC

- H01M 8/1018: Polymeric electrolyte materials
- H01M 8/1048: Ion-conducting additives, e.g. ion-conducting particles, heteropolyacids, metal phosphate or polybenzimidazole with phosphoric acid
- H01M 8/1053: consisting of layers of polymers with at least one layer being ionically conductive
- H01M 8/1004: characterised by membrane-electrode assemblies [MEA] (H01M8/12 takes precedence)
- H01M 2300/0082: Organic polymers
- H01M 2300/0091: in the form of mixtures
- Y02E 60/50: Fuel cells
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

Provided are a polymer electrolyte membrane for fuel cells, and a membrane electrode assembly and a fuel cell including the same. More specifically, provided is a polymer electrolyte membrane for fuel cells including a hydrocarbon-based cation exchange resin having hydrogen ion conductivity and fibrous nanoparticles having a hydrophilic group. By using the fibrous nanoparticles having a hydrophilic group in conjunction with the hydrocarbon-based cation exchange resin having hydrogen ion conductivity, it is possible to obtain a polymer electrolyte membrane for fuel cells that exhibits improved gas barrier properties and long-term resistance, without causing deterioration in performance of fuel cells, and a fuel cell including the polymer electrolyte membrane.

## Claims

### Claim 1

A polymer electrolyte membrane for fuel cells comprising:
a hydrocarbon-based cation exchange resin having hydrogen ion conductivity; and
fibrous nanoparticles having a hydrophilic group,
wherein a mix ratio of the hydrocarbon-based cation exchange resin having hydrogen ion conductivity and the fibrous nanoparticles having a hydrophilic group is 99.9:0.1 to 91:9 on a weight ratio basis,
wherein the fibrous nanoparticles having a hydrophilic group is cellulose nanofibers, wherein the fibrous nanoparticles having a hydrophilic group has a diameter of 1 to 200 nm and a length of 1 to 20 μm and an aspect ratio of 1:5 to 1:2,000,
wherein the hydrophilic group is a hydroxyl group (-OH) and is present in an amount of 5 to 90% in the cellulose nanofibers, with respect to the total sites of the hydroxyl group (-OH), and
wherein the hydrocarbon-based cation exchange resin is one or more selected from the group consisting of benzimidazole polymers, polyimide polymers, polyetherimide polymers, polyphenylene sulfide polymers, polysulfone polymers, polyether sulfone polymers, polyether ketone polymers, polyether ether ketone polymers and polyphenyl quinoxaline polymers.

### Claim 2 (depends on 1)

The polymer electrolyte membrane according to claim 1, wherein the cellulose nanofibers are one or more selected from the group consisting of: cellulose nanofibers in which hydroxyl groups are not substituted; cellulose nanofibers substituted with an acetyl group or a derivative thereof; cellulose sulfate nanofibers; cellulose phosphate nanofibers; and cellulose nanofibers substituted with a C1-C10 alkyl group or a derivative thereof.

### Claim 3 (depends on 2)

The polymer electrolyte membrane according to claim 2, wherein the cellulose nanofibers are one or more selected from the group consisting of cellulose nanofibers in which hydroxyl groups are not substituted; cellulose nanofibers substituted with an acetyl group or a derivative thereof; cellulose sulfate nanofibers; cellulose phosphate nanofibers; and cellulose nanofibers substituted with a C2-C6 alkyl group or a derivative thereof.

### Claim 4 (depends on 1)

The polymer electrolyte membrane according to claim 1, wherein the hydrocarbon-based cation exchange resin having hydrogen ion conductivity is a polymer provided at a side chain thereof with one or more cation exchange groups selected from the group consisting of a sulfonic acid group, a carboxylic acid group, phosphoric acid group, a phosphonic acid group and a derivative thereof.

### Claim 5 (depends on 1)

The polymer electrolyte membrane according to claim 1, wherein the hydrocarbon polymer is a polyether ether ketone polymer, polyethersulfone polymer, or a mixture thereof.

### Claim 6 (depends on 1)

A membrane electrode assembly for fuel cells in which the polymer electrolyte membrane for fuel cells according to claim 1 is interposed between an anode and a cathode that face each other.

### Claim 7 (depends on 6)

A fuel cell comprising the membrane electrode assembly for fuel cells according to claim 6 and one or more separation plates,
the fuel cell comprising:
one or more electricity generators to generate electricity through electrochemical reaction of a fuel and an oxidizing agent;
a fuel feeder to feed fuel to the electricity generators; and
an oxidizing agent feeder to feed an oxidizing agent to the electricity generators.