Angled Coating for Nonrectangular Fuel Cell Membranes

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Solution Overview

Problem

Conventional methods for producing catalyst coated membranes with nonrectangular active areas result in excessive coating of inactive areas, leading to wastage of catalytic material and increased production costs, as they often require slow and costly printing processes or inefficient continuous coating methods that coat beyond the active area.

Innovation Solution

A method involving a continuous coating process where the catalytic material is applied at an angle to the membrane, ensuring the coated area covers only the active area with a constant width, reducing excessive coating and allowing for the recycling of excess catalytic material, particularly suitable for producing membranes with nonrectangular active areas like hexagonal contours.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If continuous coating processes are used to coat the membrane continuously with catalytic material, then production rate increases and labor intensity decreases, but inactive areas are adversely coated with catalytic material causing material waste

Engineering Contradiction:

Improveproduction rateVSAvoidcatalytic material waste

Core Design Contradiction:

ProductivityVSLoss of substance

Solution Approach 1:

The membrane surface is segmented into active and inactive areas. The coating process is divided into two stages: first coating the entire membrane surface, then selectively removing catalyst from inactive areas through etching or masking techniques. This allows continuous production while minimizing catalyst waste in non-active regions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different surface properties are applied to different areas of the membrane. The active areas maintain catalytic coating while inactive areas are treated with etching patterns or masks to prevent catalyst deposition. This creates local quality differences that optimize both production efficiency and material utilization.

Inventive Principle:

Principle #3Local quality

2Loss of substance

If printing processes are used to selectively coat only the active area, then catalytic material waste is reduced, but production rate decreases and equipment cost increases

Engineering Contradiction:

Improvecatalytic material wasteVSAvoidproduction rate

Core Design Contradiction:

Loss of substanceVSProductivity

Solution Approach 1:

The membrane surface is pre-treated with etching patterns or masks before the continuous coating process. This preliminary action defines the active and inactive areas in advance, allowing the subsequent continuous coating to automatically deposit catalyst only where needed, combining selectivity with high production rate.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

An intermediary layer such as a mask or etching pattern is introduced between the coating source and the membrane surface. This intermediary selectively blocks catalyst deposition in inactive areas while allowing continuous coating in active areas, achieving both material efficiency and high productivity.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If the membrane is coated with catalytic material covering the active area, then the active area functionality is ensured, but inactive areas are also coated requiring subsequent blocking and increasing process complexity

Engineering Contradiction:

Improveactive area functionalityVSAvoidprocess complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Instead of coating only active areas and leaving inactive areas blank, the process inverts the approach by first coating the entire surface and then selectively removing or blocking catalyst in inactive areas. This inversion simplifies the coating process while maintaining active area functionality and reducing the need for complex blocking procedures.

Inventive Principle:

Principle #13The other way round (Inversion)

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 approach significantly reduces the amount of catalytic material used, minimizes inactive area coating, and enables high production rates by integrating the coating process with continuous roller methods, thereby optimizing the use of expensive catalytic materials and reducing production costs.

Implementation Method 1

a continuous application of a catalytic material to a membrane material taking place in such a manner that a coated surface is created with a constant coating width

Methodology Applied

Scientific EffectDeposition: Deposition (physical)

Data Source

PatentUS10431844B2Method for producing a catalytically coated membrane and membrane electrode assembly and fuel cell stack having same

Publication Date: 2019.10.01 AUDI AG

AI summary

The invention relates to a method for producing a catalyst coated membrane (19) for a fuel cell (10), wherein the catalyst coated membrane (19) has a membrane (11) and a catalyst layer (12, 13) of a catalytic material arranged on at least one of its flat sides, as well as a nonrectangular active area (20), which is restricted in one direction by two outer sides (30) opposite one another. The method comprises a continuous application of the catalytic material to a membrane material (33) while creating a constant coating width (B) such that an area (35) coated with the catalytic material corresponds to at least the active area (20). A provision is that the membrane material (33) be coated with the catalytic material such that a coating direction (D) has an angle with respect to the opposite outer sides (30) of the active area (20) that is not equal to 90° and not equal to 0°.