TiO2 Coated PEM for Water Electrolysis

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Solution Overview

Problem

The crossover of O2 from the cathode to the anode in proton exchange membrane (PEM) water electrolysis systems is detrimental, as it can form H2O2 at the anode, which decomposes into radicals that attack the membrane, causing damage.

Innovation Solution

A proton exchange membrane for water electrolysis is developed, featuring a proton exchange substrate coated on one side with a titanium oxide (TiO2) film of thickness equal to or smaller than 100 nm, deposited using spatial atomic layer deposition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a thick titanium oxide film is deposited on the proton exchange substrate to reduce O2 permeation, then the protection against oxidative damage is improved, but the proton conductivity is significantly reduced

Engineering Contradiction:
Improveprotection against oxidative damageVSAvoidproton conductivity
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent optimizes the thickness parameter of the titanium oxide film to be between 1 nm and 100 nm, specifically finding that 5-50 nm provides the best balance. This parameter optimization reduces O2 permeation while maintaining adequate proton conductivity, resolving the contradiction between protection and conductivity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The titanium oxide film is applied selectively on specific surfaces of the proton exchange substrate (anode side or both sides) rather than uniformly throughout the entire membrane structure. This localized application provides oxidative damage protection at the critical interfaces while preserving proton conductivity through the bulk membrane material.

Inventive Principle:
Principle #3Local quality

2Use of energy by moving object

If the proton exchange membrane is made thinner to improve proton conductivity, then the proton conductivity is improved, but the mechanical strength and durability are reduced

Engineering Contradiction:
Improveproton conductivityVSAvoidmechanical strength
Core Design Contradiction:
Use of energy by moving objectVSStrength

Solution Approach 1:

The patent creates a composite structure combining the proton exchange substrate with a titanium oxide coating layer. This composite provides both the proton conductivity of the polymer substrate and the oxidative resistance and mechanical reinforcement of the titanium oxide film, allowing thin membranes to maintain adequate strength.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The titanium oxide film acts as a protective thin film coating on the proton exchange substrate, providing mechanical reinforcement and oxidative protection without significantly increasing overall thickness. This allows the membrane to maintain thin dimensions for good proton conductivity while gaining strength from the coating.

Inventive Principle:
Principle #30Flexible shells and thin films

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 titanium oxide film effectively reduces O2 permeation without significantly impacting proton conductivity, thereby protecting the membrane from oxidative damage and maintaining performance in water electrolysis.

Implementation Method 1

permeation of O2 through the proton exchange membrane is reduced

Methodology Applied
Scientific EffectPermeation: Permeation

Implementation Method 2

the titanium oxide film being deposited by spatial atomic layer deposition

Methodology Applied
Scientific EffectPhysical vapor deposition: Physical Vapour Deposition

Data Source

PatentEP4541944A1Improved proton exchange membrane for water electrolysis
Publication Date: 2025.04.23 TOYOTA JIDOSHA KK
  • EP4541944A1 patent drawingFigure 1~3
  • EP4541944A1 patent drawingFigure 4~5
  • EP4541944A1 patent drawingFigure 6~7

AI summary

A proton exchange membrane (10) for water electrolysis comprising a proton exchange substrate (12) coated on one side with a titanium oxide film (14), the titanium oxide film having a thickness (t14) equal to or smaller than 100 nm. A method for making a proton exchange membrane for water electrolysis.