Test methods for the quality assurance during the production of PEM fuel cells

Contents

1. Fundamentals of the fuel cell technology

1.1 History of fuel cells

1.2 Applications

1.3 Types

1.4 Principals

1.5 Structure and components of a PEMFC

1.5.1 Proton exchange membrane

1.5.2 Cathode/Anode catalyst layer

1.5.3 Gas diffusion layer

1.5.4 Bipolar plates

1.5.5 Front/End plates

2. Control Plan

2.1 Methodology

2.2 FMEA

2.3 Control parameters

2.3.1 Thickness variation of the MEA

2.3.2 Electrolyte cluster

2.3.3 Delamination

2.3.4 Catalyst cluster

2.3.5 Humidification

2.3.6 Cracking

2.3.7 Flow field structure in the bipolar plates

2.3.8 Tightness of the fuel cell

2.3.9 Temperature

2.3.10 Impedance

3. Control methods and plan

3.1 Cluster and cracks detection in the catalyst layer

3.1.1 IR thermography

3.1.2 Cluster detection with scanning electron microscope (SEM)

3.2 Flow field structure control of the bipolar plates

3.2.1 Image processing

3.3 Tightness control

3.4 Delamination control

3.5 Impedance control

3.5.1 High frequency resistance method

3.5.2 Current interrupt method

3.6 Membrane thickness control

4. Measurement uncertainties

4.1 Thickness measurement uncertainties

4.2 Impedance measurement uncertainties

4.3 Temperature measurement uncertainties

5. Conclusion and outlook

5.1 Conclusion

5.2 Outlook

Objectives and Research Themes

The primary objective of this work is to shorten the duration of end-of-line tests for PEM fuel cells to enable mass production, achieved through the development of a comprehensive, assembly-accompanying control plan. The study focuses on the following themes:

• Fundamental analysis of PEM fuel cell components and their operational requirements.
• Execution of a Failure Mode and Effects Analysis (FMEA) to identify critical manufacturing defects.
• Selection and evaluation of non-destructive, high-speed inline inspection technologies.
• Development of a monitoring system for key quality parameters such as thickness, tightness, and impedance.
• Assessment of measurement uncertainties to ensure reliable quality control resolution.

Excerpt from the Book

Summary of Chapters

1. Fundamentals of the fuel cell technology: This chapter covers the historical development, operating principles, and specific components of PEM fuel cells to provide a technical basis for the work.

2. Control Plan: This section details the FMEA methodology used to identify potential manufacturing defects and establishes the critical control parameters for production.

3. Control methods and plan: This chapter presents specific inline testing technologies, such as IR thermography, image processing, and EMAT, to monitor identified defects during assembly.

4. Measurement uncertainties: This section defines the relationship between measurement tolerances and uncertainties to determine the necessary resolution for inspection instrumentation.

5. Conclusion and outlook: The final chapter summarizes the findings regarding the reduction of end-of-line test durations and proposes future experimental validation steps.

Keywords

PEM fuel cell, mass production, quality assurance, FMEA, end-of-line test, IR thermography, EMAT, impedance control, manufacturing defects, electrolyte cluster, delamination, stack, catalyst layer, membrane, inline inspection

Frequently Asked Questions

What is the core focus of this thesis?

The thesis focuses on improving the quality assurance processes for the mass production of PEM fuel cells by reducing the time required for end-of-line testing.

What are the central thematic fields?

The research covers fuel cell component functionality, failure mode analysis, selection of inline inspection methods, and the determination of required measurement resolutions.

What is the primary research goal?

The goal is to develop a montage-accompanying control plan that minimizes the duration of end-of-line tests while maintaining high production quality.

Which scientific method is utilized?

The work utilizes a Failure Mode and Effects Analysis (FMEA) to identify defects, coupled with a literature review and the evaluation of state-of-the-art testing technologies.

What is addressed in the main body of the work?

The main body includes a structural and functional analysis of fuel cell components, a detailed FMEA, the design of a control plan using various diagnostic methods, and an analysis of measurement uncertainties.

Which keywords characterize the work?

Key terms include PEM fuel cell, mass production, quality assurance, FMEA, end-of-line test, and various detection technologies like IR thermography and EMAT.

How does IR thermography contribute to quality assurance?

IR thermography allows for rapid, non-contact detection of cracks and catalyst clusters by visualizing the heat signatures generated during the reaction process.

Why is the delamination control important for the stack?

Delamination between the catalyst layer and the membrane increases ionic resistance and heat generation, which significantly reduces performance and can lead to the formation of pinholes.

How does the EMAT technique facilitate high-speed inspection?

EMAT is a non-contact ultrasonic technique that allows for high-speed in-line scanning of multilayered structures without the need for couplants.

What is the significance of the "Rule of 10"?

The Rule of 10 illustrates that the cost of correcting a defect increases significantly the later it is detected in the product lifecycle, justifying early production-phase inspection.