Composite Ion-Exchange Membrane Dimensional Stability

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Solution Overview

Problem

Electrochemical devices face membrane degradation due to swelling and contraction caused by water uptake, leading to delamination and cracking issues in fuel cells and other electrochemical systems.

Innovation Solution

A composite ion-exchange membrane is developed by reacting a porous support made of a polymer with reactive amine groups with a polymer containing a haloalkyl group, forming a covalent bond and introducing cationic functional groups, which enhances dimensional stability and hydroxide ion conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional ion-exchange membrane is used, then ion conductivity is achieved, but dimensional stability deteriorates due to swelling and contraction

Engineering Contradiction:
Improvedimensional stabilityVSAvoidmembrane swelling
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent applies composite materials by combining a porous polymer support with an ion-exchange membrane layer. The porous support provides dimensional stability while the ion-exchange membrane provides ion conductivity. This composite structure resolves the contradiction by allowing the membrane to function while the support prevents excessive swelling and contraction.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent uses a porous polymer support material with controlled porosity to accommodate the ion-exchange membrane. The porous structure allows water uptake and swelling to occur within the pores rather than causing planar expansion, thereby maintaining dimensional stability while preserving ion conductivity pathways.

Inventive Principle:
Principle #31Porous materials

2Quantity of substance

If the membrane swells in the channel region, then water absorption capacity increases, but membrane electrode assembly integrity deteriorates due to delamination and cracking

Engineering Contradiction:
Improvewater absorptionVSAvoidmembrane electrode assembly integrity
Core Design Contradiction:
Quantity of substanceVSStrength

Solution Approach 1:

The porous support material provides a three-dimensional network that accommodates water absorption vertically within the pores rather than allowing horizontal expansion. This prevents the membrane from delaminating from the electrode layers or cracking, while still maintaining adequate water absorption capacity for ion transport.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent redirects the swelling direction from the plane (horizontal) to the thickness direction (vertical) by using a porous support structure. This dimensional change allows water absorption to occur without compromising the planar integrity of the membrane electrode assembly.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The composite membrane exhibits reduced dimensional changes, improved stability, and enhanced hydroxide ion conductivity, enabling stable operation in electrochemical devices like fuel cells and water electrolyzers with reduced risk of cracking and delamination.

Implementation Method 1

a covalent bond is formed through Step 1 between the porous support consisting of the polymer comprising a reactive amine group and the polymer comprising a haloalkyl group

Methodology Applied
Scientific EffectCovalent bonding: Chemical Bonding

Implementation Method 2

the porous support, by having the form of a porous mat, is able to sufficiently accommodate the polymer comprising a haloalkyl group within its pores

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP3923389A1Composite ion-exchange membrane, method of preparing the same, and use thereof
Publication Date: 2021.12.15 KOREA INST OF SCI & TECH
  • EP3923389A1 patent drawingFigure 1
  • EP3923389A1 patent drawingFigure 2
  • EP3923389A1 patent drawingFigure 3

AI summary

The present invention relates to a method of preparing a composite ion-exchange membrane supported with a porous polymer material, a composite ion-exchange membrane prepared by the method, and a use thereof.