Redox Flow Cell Electrode Sealing With Snap-Fit Assembly

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Solution Overview

Problem

Existing redox flow cells face challenges in securely and efficiently sealing metallic electrodes due to the chemical aggressiveness of electrolytes and the delicate design of electrode frames, leading to reduced service life and increased manufacturing costs.

Innovation Solution

A redox flow cell design featuring an electrode module with an inwardly directed seal having a snap nose and elastic sealing lips, which allows for easy assembly and secure fixation of the electrode, along with a membrane module that provides additional sealing and support, using thermoplastic materials resistant to chemical aggression.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional molded seals with undercut grooves are used in the electrode frame, then sealing capability is improved, but manufacturing complexity increases due to the closed circumferential groove and force-fitting connection requirements

Engineering Contradiction:
Improvesealing capabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The seal is divided into multiple independent sealing lips (first sealing lip, second sealing lip, third sealing lip) that can be separately molded and assembled, eliminating the need for complex undercut grooves and force-fitting connections while maintaining effective sealing capability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sealing lips are pre-formed with integrated attachment features (such as attachment protrusions) that enable direct form-fitting connection to the electrode frame without requiring subsequent complex assembly operations or undercut grooves

Inventive Principle:
Principle #10Preliminary action

2Reliability

If formed-in-place (FIP) seals are applied using dispensing processes, then sealing is achieved, but production time increases making the process economically unviable

Engineering Contradiction:
Improvesealing effectivenessVSAvoidassembly cycle time
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The seals are pre-formed as discrete components with integrated attachment features before assembly, eliminating the need for time-consuming dispensing processes and allowing for rapid assembly through simple snap-fit connections

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The complex dispensing and curing process is replaced with a mechanical snap-fit assembly system that enables rapid sealing without chemical adhesives or extended processing times

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If elastic adhesives are used to seal the electrode to the electrode frame, then sealing is achieved, but adhesive leaching occurs due to chemical aggressiveness of the electrolyte

Engineering Contradiction:
Improvesealing capabilityVSAvoidadhesive leaching
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The adhesive layer is completely removed from the sealing system and replaced with mechanical form-fitting connections between the seal and electrode frame, eliminating the source of leaching contamination

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The seal is designed as a self-contained component with integrated attachment features that provides sealing through mechanical interference fit rather than chemical adhesion, making the system resistant to electrolyte degradation

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

4Strength

If thermoplastic electrode frame and metallic electrode are joined with adhesive, then connection is achieved, but differential thermal expansion creates significant shear stresses reducing service life

Engineering Contradiction:
Improvebond strengthVSAvoidservice life
Core Design Contradiction:
StrengthVSDuration of action of stationary object

Solution Approach 1:

The adhesive layer is eliminated and replaced with a mechanical form-fitting connection system that joins the electrode frame and electrode through geometric interlocking rather than chemical bonding, avoiding shear stress concentration

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The connection mechanism transitions from chemical adhesion to mechanical interference fit, changing the stress distribution characteristics and eliminating the problematic shear stresses that arise from differential thermal expansion

Inventive Principle:
Principle #35Parameter changes

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 solution enables a secure, efficient, and long-lasting seal for the electrode, allowing for quick assembly and disassembly while maintaining chemical resistance, thus enhancing the operational lifespan and reducing manufacturing complexity.

Implementation Method 1

The first elastic sealing lip is arranged within the inner circumference of the holding frame and formed for lateral sealing and lateral support of the electrode

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

An at least partially circumferential snap-in nose is formed on an inner circumference of the holding frame for circumferentially receiving an electrode

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP4331028B1Redox flow cell and method for installation thereof and redox flow battery
Publication Date: 2024.12.11 SCHAEFFLER TECHNOLOGIES AG & CO KG
  • EP4331028B1 patent drawingFigure 1~6

AI summary

The present invention relates to a redox flow cell having an electrode module (10). The electrode module (10) comprises an electrode frame (01) having a seal (03) extending around its inner circumference. The seal (03) has at least one holding frame (07) and a first resilient sealing lip (09). A snap-action catch (08) to hold an electrode (02) extends around at least part of the inner circumference of the holding frame (07). The first sealing lip (09) is arranged inside the inner circumference of the holding frame (07) and is designed for lateral sealing and support of the electrode (02). The electrode module (10) further comprises the electrode (02), the outer circumference of which is snapped into the snap-action catch (08) of the retaining frame (07), so that the electrode (02) is pressed laterally against the first resilient sealing lip (09). The redox flow cell also has a membrane module (20) which is fixedly connected to the electrode module (10) and comprises a membrane frame (21) and a membrane (22). The electrode (02) is gripped between circumferential pressing elements (23) of the membrane frame (21) and the first resilient sealing lip (09) of the seal (03). The invention further relates to a redox flow battery and to a method for installing a redox flow cell.