# US 10,374,246 B2 · Ion exchange membrane and manufacturing method therefor

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,374,246 B2
- Document ID: US10374246B2
- Status: Granted
- Kind: B2
- Application number: 15/038,814
- Filed: 2014-11-25
- Published: 2016-12-29
- Granted: 2019-08-06
- Earliest claimed: 2013-11-25
- Assignees: Hyundai Electric & Energy Systems Co., Ltd.
- Applicants: Hyundai Electric & Energy Systems Co., Ltd.; Postech Academy-Industry Foundation
- Inventors: Ji Hyun Kong; Jung Yun Kim; Eun Jung Choi; Moon Jeong Park; Il Young Choi; Sung Yeon Kim; Ho Il Lee
- Web page: https://patentgrep.com/patent/US10374246B2

## CPC

- H01M 8/1023: having only carbon, e.g. polyarylenes, polystyrenes or polybutadiene-styrenes
- C08J 5/2243: {obtained by introduction of active groups capable of ion-exchange into compounds of the type C08J5/2231}
- H01M 8/1072: by chemical reactions, e.g. in situ polymerisation or in situ crosslinking
- H01M 8/188: {by recharging of redox couples containing fluids; Redox flow type batteries}
- C08J 2353/02: of vinyl aromatic monomers and conjugated dienes
- Y02E 60/50: Fuel cells
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- 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
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

The present invention relates to an ion exchange membrane and a manufacturing method therefor and, more specifically, to an ion exchange membrane comprising a cross-linked sulfonated triblock copolymer and carbon nanotube, which is utilizable in a redox flow energy storage device, etc. due to high ion conductivity, mechanical strength and ion selectivity. The ion exchange membrane of the present invention has superior ion selectivity and mechanical strength and thus can greatly improve the performance of a fuel battery, etc. when applied thereto.

## Claims

### Claim 1

An ion exchange membrane comprising:
a cross-linked sulfonated triblock copolymer in which a first sulfonated block, a crosslinking block and a second sulfonated block are arranged sequentially, wherein the crosslinking block is a polyisoprene block; and
dispersed sulfonated carbon nanotubes comprising sulfonates directly attached to a surface of the carbon nanotube, wherein the sulfonates are present in an amount of 0.1-70 parts by weight based on 100 parts by weight of carbon nanotubes.

### Claim 2 (depends on 1)

The ion exchange membrane according to claim 1, wherein the sulfonated block is a polystyrene block.

### Claim 3 (depends on 2)

The ion exchange membrane according to claim 2, wherein the polystyrene block has a molecular weight of 6.5-19.2 kg/mol.

### Claim 4 (depends on 1)

The ion exchange membrane according to claim 1, wherein the cross-linking is formed merely in the cross-linking block.

### Claim 5 (depends on 1)

The ion exchange membrane according to claim 1, wherein the cross-linking block has a cross-linking degree of 0.5-5%.

### Claim 6 (depends on 1)

The ion exchange membrane according to claim 1, wherein the sulfonation is carried out in the sulfonated blocks and the sulfonated blocks have a sulfonation degree of 25-65%.

### Claim 7 (depends on 1)

The ion exchange membrane according to claim 1, wherein each single monomer block of the block copolymer has a molecular weight of 20-150 kg/mol.

### Claim 8 (depends on 1)

The ion exchange membrane according to claim 1, wherein the sulfonated carbon nanotubes are present in an amount of 1-5 parts by weight based on 100 parts by weight of the ion exchange membrane.

### Claim 9 (depends on 1)

The ion exchange membrane according to claim 1, wherein the polyisoprene block has a molecular weight of 12.6-25 kg/mol.

### Claim 10 (depends on 1)

A redox flow battery comprising the ion exchange membrane as defined in claim 1.

### Claim 11 (depends on 10)

The redox flow battery according to claim 10, which is a vanadium redox flow battery.

### Claim 12

A method for manufacturing an ion exchange membrane, comprising the steps of:
forming a triblock copolymer in which a first sulfonated block, a cross-linking block and a second sulfonated block are arranged sequentially, wherein the cross-linking block is a polyisoprene block;
hydrogenating a part of the doubles bonds of the cross-linking block;
sulfonating at least one of the sulfonated blocks;
carrying out cross-linking of the cross-linking block to obtain a cross-linked sulfonated triblock copolymer; and
dispersing sulfonated carbon nanotubes comprising sulfonates directly attached to a surface of the carbon nanotube to the cross-linked sulfonated triblock copolymer, wherein the sulfonates are present in an amount of 0.1-70 parts by weight based on 100 parts by weight of carbon nanotubes.

### Claim 13 (depends on 12)

The method according to claim 12, wherein the sulfonated blocks are polystyrene blocks.

### Claim 14 (depends on 12)

The method according to claim 12, wherein the crosslinking and sulfonation are carried out simultaneously by using acetic sulfate.

### Claim 15 (depends on 12)

The method according to claim 12, wherein the sulfonated carbon nanotubes are obtained by mixing carbon nanotubes with aqueous ammonium sulfate and heating the mixture at a temperature of 200-250° C. for 25-40 minutes.