Water Electrolysis Stack Pressure Equalization for Seal Durability

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Solution Overview

Problem

The presence of inter-cell spaces in a fuel cell stack used as a water electrolysis stack leads to deformation due to pressure from reaction water and generated hydrogen, compromising the hermetic seal and durability of the water electrolysis cells.

Innovation Solution

Incorporating communicating holes and channels to facilitate the flow of hydrogen and reaction water through the stack, allowing for the equalization of pressures and preventing deformation of inter-cell spaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If inter-cell spaces are formed between water electrolysis cells, then cooling water can flow through to control temperature, but the inter-cell spaces deform due to pressure from reaction water and generated hydrogen, compromising hermetic seal and durability

Engineering Contradiction:
Improvetemperature controlVSAvoiddurability and hermetic seal
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent removes the inter-cell spaces from the water electrolysis stack structure, eliminating the source of the problem. By stacking water electrolysis cells directly adjacent to each other without intervening cooling channels, the design prevents pressure-induced deformation while maintaining structural integrity and hermetic sealing.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent integrates cooling water channels within the individual water electrolysis cell structures rather than relying on inter-cell spaces. This allows each cell to independently manage its own thermal regulation without compromising the overall stack structure or durability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of manufacture

If a fuel cell stack structure is used for water electrolysis, then the stack can be formed by stacking cells with inter-cell spaces, but the inter-cell spaces are deformed by pressure from reaction water and hydrogen, reducing durability

Engineering Contradiction:
Improvestack assemblyVSAvoiddurability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent extracts and removes the inter-cell spaces from the stack structure, preventing the pressure-induced deformation issue while maintaining the modular stacked configuration for ease of manufacture and assembly.

Inventive Principle:
Principle #2Taking out (Extraction)

3Temperature

If cooling water flows through inter-cell spaces, then temperature rise from water electrolysis can be controlled, but cooling water pressure deforms the inter-cell spaces and adjacent cells, impairing water tightness and airtightness

Engineering Contradiction:
Improvetemperature controlVSAvoidwater tightness and airtightness
Core Design Contradiction:
TemperatureVSStrength

Solution Approach 1:

The patent segments the cooling water flow system into individual cell-level channels rather than using shared inter-cell spaces. This allows independent temperature control for each cell while preventing pressure-induced deformation that would compromise water tightness and airtightness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent removes the inter-cell spaces that were causing the structural deformation problem, eliminating the source of water tightness and airtightness issues while maintaining effective temperature control through integrated cell-level cooling channels.

Inventive Principle:
Principle #2Taking out (Extraction)

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

Prevents deformation of inter-cell spaces, thereby enhancing the durability and maintaining the hermetic seal of the water electrolysis stack.

Implementation Method 1

hydrogen generated at the hydrogen electrode flows from the first communicating hole via the first channel to the second communicating hole to flow to the inter-cell spaces

Methodology Applied
Scientific EffectPressure equalization: Pascal's Law

Implementation Method 2

a reaction water is fed to oxygen electrodes to perform water electrolysis. The temperature of the water electrolysis stack rises by the water electrolysis, whereas this temperature rise can be controlled by the reaction water

Methodology Applied
Scientific EffectTemperature control through fluid flow: Convection

Implementation Method 3

water electrolysis generates hydrogen at the hydrogen electrodes

Methodology Applied
Scientific EffectWater electrolysis: Electrolysis

Data Source

PatentEP4653583A1Water electrolysis stack and water electrolysis system
Publication Date: 2025.11.26 TOYOTA JIDOSHA KK
  • EP4653583A1 patent drawingFigure 1
  • EP4653583A1 patent drawingFigure 2
  • EP4653583A1 patent drawingFigure 3

AI summary

Provided is a water electrolysis stack capable of improving durability. The water electrolysis stack includes a cell stack that is formed by stacking a plurality of water electrolysis cells, an inter-cell space is formed between each adjacent ones of the water electrolysis cells in the cell stack, and gas flows into the inter-cell spaces in water electrolysis.