Electrode Structure with Recombination Layer for Water Electrolyzer

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Solution Overview

Problem

Conventional solid polymer water electrolyzers face the challenge of hydrogen crossover, where hydrogen generated on the cathode side permeates back to the anode side, mixing with oxygen and reducing efficiency, due to the thinning of the electrolyte membrane which increases ionic resistance.

Innovation Solution

An electrode structure with a recombination layer containing platinum, iridium, cobalt, or ruthenium is introduced between the anode-side surface of the electrolyte membrane and the anode catalyst particles, which combines permeated hydrogen with oxygen to form water, preventing its output from the anode side, while supporting anode catalyst particles in a porous layer to reduce the anode catalyst layer thickness and application processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the electrolyte membrane thickness is reduced, then ionic resistance is decreased and hydrogen production efficiency is improved, but hydrogen permeation into the anode side increases causing mixture with oxygen

Engineering Contradiction:
Improvehydrogen production efficiencyVSAvoidhydrogen crossover
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

A recombination layer is introduced as an intermediary between the electrolyte membrane and the anode catalyst particles. This layer mediates the interaction by catalytically converting permeated hydrogen back to water before it can mix with oxygen, thus resolving the contradiction between maintaining thin membrane for efficiency and preventing hydrogen crossover

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If a recombination layer is added to suppress hydrogen crossover, then hydrogen-oxygen mixture is prevented, but device complexity and manufacturing complexity increase

Engineering Contradiction:
Improvehydrogen crossoverVSAvoidelectrode structure complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The recombination layer is merged with the anode electrode structure, forming an integrated assembly where the recombination layer, anode catalyst particles, and porous support layer work together as a unified functional unit, thereby reducing overall device complexity while maintaining hydrogen crossover suppression

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If anode catalyst particles are supported in a porous layer, then catalyst layer thickness is reduced and application processes are simplified, but catalyst particle distribution control becomes more difficult

Engineering Contradiction:
Improveapplication process simplicityVSAvoidcatalyst particle distribution
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

A porous support layer is utilized to hold the anode catalyst particles. The porous structure naturally provides distribution pathways and surface area for uniform catalyst particle dispersion, achieving both ease of manufacture through simple application processes and manufacturing precision through controlled pore structures that guide particle placement

Inventive Principle:
Principle #31Porous materials

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

This configuration effectively suppresses hydrogen crossover, reduces ionic resistance, and enhances hydrogen production efficiency by converting permeated hydrogen back into water, thereby improving the overall performance of the water electrolyzer.

Implementation Method 1

The recombination layer contains platinum, iridium, cobalt, or ruthenium... it is possible to combine the hydrogen having permeated with oxygen to turn the hydrogen into water again in the recombination layer

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

hydrogen ions (H+) move from the anode-side catalyst layer to the cathode-side catalyst layer through the electrolyte membrane

Methodology Applied
Scientific EffectIonic conduction: Conduction (electrical)

Implementation Method 3

anode catalyst particles located on an anode side of the electrolyte membrane and used for electrolyzing water into a hydrogen ion, oxygen, and an electron

Methodology Applied
Scientific EffectElectrolysis: Electrolysis

Implementation Method 4

cathode catalyst particles located on a cathode side of the electrolyte membrane and used for combining the hydrogen ion and the electron with each other to produce hydrogen

Methodology Applied
Scientific EffectElectrochemical reduction: Redox Reactions

Data Source

PatentEP4442861A1Electrode structure and water electrolyzer
Publication Date: 2024.10.09 SCREEN HOLDINGS CO LTD
  • EP4442861A1 patent drawingFigure 1
  • EP4442861A1 patent drawingFigure 2
  • EP4442861A1 patent drawingFigure 3

AI summary

An electrode structure includes an electrolyte membrane (51), a plurality of anode catalyst particles (611) located on an anode side of the electrolyte membrane (51), a plurality of cathode catalyst particles located on a cathode side of the electrolyte membrane, and a recombination layer (80) located between the electrolyte membrane (51) and the anode catalyst particles (611). The anode catalyst particles are used for electrolyzing water into a hydrogen ion, oxygen, and an electron. The cathode catalyst particles are used for combining the hydrogen ion and the electron with each other to produce hydrogen. If hydrogen generated on the cathode side of the electrolyte membrane (51) permeates into the anode side across the electrolyte membrane (51), the hydrogen having permeated is combined with oxygen to turn into water again in the recombination layer (80). This makes it possible to suppress mixture of hydrogen into oxygen to be output from the anode side.