Transfer Sheet Gas Occlusion Structure for Catalyst Layer Peeling

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Solution Overview

Problem

Existing methods for manufacturing membrane electrode assemblies in solid polymer fuel cells face issues with insufficient peelability of the base sheet, leading to defects such as cracks and holes in the catalyst layer.

Innovation Solution

Incorporating gas occlusion bodies on the transfer sheet that store and release gas upon application of energy, allowing for easy separation of the base sheet from the catalyst layer without causing damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a resin film is used as the base sheet with adjusted physical properties or release layer to improve transferability, then the transferability of the catalyst layer is improved, but the peelability remains insufficient and defects such as cracks and holes may occur in the catalyst layer

Engineering Contradiction:

ImprovetransferabilityVSAvoidpeelability

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

Gas occlusion bodies are incorporated into the transfer layer before the transfer process. These bodies pre-store gas that will be released during peeling to facilitate separation. The gas occlusion bodies are positioned in advance within the transfer layer structure, ready to expand and create separation force when energy is applied during the peeling stage.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The gas occlusion bodies undergo a phase transition or expansion when energy is applied to them. This expansion transforms the stored gas into a force that pushes the transfer layer away from the base sheet, enabling easy peeling. The energy input causes the gas occlusion bodies to expand or release gas, creating the necessary separation force.

Inventive Principle:

Principle #36Phase transitions

2Ease of operation

If strong peeling force is applied to improve peelability, then the base sheet can be separated from the transfer layer, but cracks and holes occur in the catalyst layer

Engineering Contradiction:

ImprovepeelabilityVSAvoidintegrity of catalyst layer

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

Gas occlusion bodies act as an intermediary mechanism between the transfer layer and base sheet during peeling. Instead of applying direct mechanical force that could damage the catalyst layer, the expanding gas occlusion bodies create a gentle separation force that pushes the layers apart, protecting the catalyst layer from damage while achieving effective peeling.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The traditional mechanical peeling force is replaced with a gas expansion mechanism. Instead of relying on mechanical tension and force to separate the layers, the system uses gas occlusion bodies that expand when energy is applied, substituting mechanical force with gas pressure to achieve separation without damaging the catalyst layer.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If a specialized resin film with improved peelability is used, then the peelability is enhanced, but the manufacturing cost increases

Engineering Contradiction:

ImprovepeelabilityVSAvoidmanufacturing cost

Core Design Contradiction:

Ease of operationVSEase of manufacture

Solution Approach 1:

The gas occlusion bodies serve multiple functions: they facilitate peeling, protect the catalyst layer during separation, and can be incorporated into standard resin films without requiring specialized materials. This multi-functional approach allows the use of conventional, cost-effective base sheets while achieving improved peelability through the added gas occlusion mechanism.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The peeling process is improved by changing the energy state of the gas occlusion bodies rather than changing the base sheet material properties. By applying energy to expand the gas occlusion bodies, the system achieves enhanced peelability through parameter change (gas expansion) rather than through expensive material modifications, allowing use of standard resin films.

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

Improves peelability of the base sheet, reducing defects in the catalyst layer and enhancing the manufacturing process efficiency, enabling the use of less expensive resin films and improving power generation performance.

Implementation Method 1

The gas occlusion bodies store gas and release the stored gas when energy is applied

Methodology Applied

Scientific EffectGas expansion under energy input: Thermal Expansion

Data Source

PatentUS12609325B2Transfer sheet, transfer method and method for manufacturing membrane electrode assembly

Publication Date: 2026.04.21 ROBERT BOSCH GMBH

AI summary

To improve peelability of a base sheet regardless of a type of the base sheet.A transfer sheet (50A, 50B) in which a transfer layer (52) is laminated on a base sheet (51) includes a plurality of gas occlusion bodies (60) in a surface of or inside the transfer layer (52). The gas occlusion bodies (60) store gas therein and release the stored gas when energy is applied.