Anion-Conducting Membrane Polymer for Stable Ionic Conductivity

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Solution Overview

Problem

Existing anion exchange membranes for water electrolysis suffer from rapid degradation of ionic conductivity over time, leading to reduced long-term stability and increased energy consumption.

Innovation Solution

Development of polymeric compounds with a specific chemical structure, including a tertiary carbon atom and aromatic 6-rings, which are used to create anion-conducting membranes with improved long-term stability of ionic conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional anion exchange membranes are used, then initial ionic conductivity is achieved, but ionic conductivity degrades rapidly over time

Engineering Contradiction:
Improvelong-term stabilityVSAvoidservice life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent modifies the chemical structure parameters of the membrane material by introducing specific substituents (fluorine atoms, alkyl groups, aryl groups) at defined positions on the polymer backbone. These parameter changes in molecular structure enhance the membrane's resistance to chemical degradation while preserving ionic conductivity pathways, thereby extending service life without sacrificing initial performance

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite polymer structure combining multiple functional groups (sulfone, ether, ketone, fluorinated groups) within a single polymer chain. This composite molecular architecture provides both the ionic conductivity needed for initial performance and the chemical stability required for long-term operation in harsh electrochemical environments

Inventive Principle:
Principle #40Composite materials

2Productivity

If membrane material is exposed to harsh electrochemical conditions, then water electrolysis process runs, but molecular structure degrades leading to loss of ionic conductivity

Engineering Contradiction:
Improvehydrogen productionVSAvoidmolecular structure stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent incorporates chemically stable functional groups (fluorinated substituents, aromatic rings, tertiary carbon structures) into the polymer backbone before exposure to harsh conditions. These pre-installed stable structures act as protective elements that preemptively resist oxidative and hydrolytic degradation during water electrolysis, preventing molecular structure breakdown and maintaining ionic conductivity throughout the operational lifecycle

Inventive Principle:
Principle #9Preliminary anti-action

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 new compounds maintain a high percentage of initial ionic conductivity for an extended period, significantly improving the long-term stability and efficiency of anion exchange membranes in water electrolysis.

Implementation Method 1

the membrane needs to be conductive for ions (cations or anions), while almost impermeable for hydrogen and oxygen gas

Methodology Applied
Scientific EffectIonic conductivity: Conduction (electrical)

Implementation Method 2

the membrane needs to be electrically isolating

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Implementation Method 3

electrolysis of water to gain molecular hydrogen and molecular oxygen

Methodology Applied
Scientific EffectElectrolysis: Electrolysis

Data Source

PatentEP4059988B1Long-term anion-conducting compound, its preparation and its use in electrochemistry
Publication Date: 2025.05.07 EVONIK OPERATIONS GMBH
  • EP4059988B1 patent drawingFigure 1
  • EP4059988B1 patent drawingFigure 2
  • EP4059988B1 patent drawingFigure 3

AI summary

The present invention provides compounds, especially polymeric compounds, a process for preparation thereof and for the use of these compounds. Intended use is in the field of electrochemistry. Anion-conducting properties of disclosed compounds making this material suitable for the preparation of anion-conducting membranes. The object of the present invention is therefore to provide material having an ionic conductivity that is stable over long period of time. This object is solved by compounds containing at least one unit of the formula (I) wherein X being a ketone or sulfone group, wherein Z being a structure element comprising at least one tertiary carbon atom and at least one aromatic 6-ring directly bonded to one of the oxygen atoms, and wherein Y being a structure element comprising at least one nitrogen atom with a positive charge and Y being bonded to said tertiary carbon atom of Z.