An essential goal in the commercial production of fuel cells is to establish manufacturing processes that are as cost-efficient as possible.
Starting with test facilities in product development, roll-to-roll processing promises the greatest savings potential. Rising demand, especially for polymer electrolyte membrane fuel cells (PEMFC), and an ever-increasing degree of automation can bring prices down further.
But this is not the only focus of most fuel cell manufacturers around the globe. For industrial fuel cell production, it is also necessary to extend the lifetime of fuel cells and increase the efficiency of sustainable power generation based on hydrogen.
Thus, inline quality control in the production of fuel cell components is as important, as it is for companies to carry out a wide variety of trials and tests. The results can be evaluated on so-called self-sufficient test facilities.
With test facility for membrane electrode assemblies and membrane coating in particular, Printum Technology GmbH bridges the gap between research and industrial production.
Read more below
With the development of a test facility for the membrane electrode assembly (MEA), Printum Technology GmbH bridges the gap between research and industrial production.
The MEA test facility was developed in Ravensburg, Germany, to provide a offline test environment for catalyst-coated membranes. It allows full cell manufacturers to test new materials in a roll-to-roll process, optimise manufacturing processes and develop innovative products to keep up with a relatively new, but highly competitive market that offers a huge potential for growth.
Our test facility examines, for example, the quality of catalyst-coated polymer membranes and detects damage such as cracks and pinholes. A high-precision rewinder enables the integration of further testing methods such as AOI, X-ray or layer thickness measurements etc.
This not only benefits PEM fuel cell manufacturers, who can react quickly to the dynamic market changes. Customised test facility tailored to different manufacturers’ needs can be used for membrane manufacturing in the medical sector as well as for lithium-ion battery manufacturing for electric cars.
As a system integrator and web handling specialist, Printum thus contributes to the industrialisation of fuel cell manufacturing. Read more about the technical details below. (linked)
Hydrogen is a carbon-free fuel source; the only by-product of power generation inside a hydrogen fuel cell is water. This clean way of generating electricity makes polymer electrolyte membrane fuel cells or proton exchange membrane fuel cells (PEMFC) worthwhile for many industries.
In some areas, fuel cells are already being used - for example in aerospace, transportation and shipping, but also to power remote home in many rural areas of Japan.
In the future, fuel cells will eventually become the primary choice for powering vehicles. Until that time comes, fuel cell manufacturers still have to think about how to extend the lifespan of fuel cells.
Fuel cells are often described as a more sustainable alternative for power generation. Regardless of the application, fuel cells must be able to deliver energy reliably over a long period of time to meet this expectation.
The performance and service life of a fuel cell depend on the quality of the components used in its manufacture: Thus, for future commercialisation, manufacturing processes of fuel cell components need to be improved – especially in terms of their sustainability and cost efficiency.
For example, PEMFC technology requires extremely sensitive ion exchange membranes to convert chemical energy into electrical energy. Mechanical properties of the ion exchange membranes such as robustness and stability, the thickness and uniform coating with reactive catalyst material have a direct impact on the efficiency and lifespan of a fuel cell.
One way to make progress in a promising market segment like this is to develop high-performance test procedures for fuel cell components such as the membrane electrode assembly (MEA), that lies at the core of every PEM fuel cell:
Even tiny, superficial cracks and holes in the membrane or its coating can have a major impact on the service life and efficiency of a fuel cell...
The multilayer catalyst-coated membrane (CCM) is a central component of the MEA and is produced and marketed for PEMFCs by manufacturers such as Nafion.
Most commercially available proton exchange membranes are made of polymers. An extremely thin catalyst layer is applied to both sides of the polymer membrane – anode and cathode, where oxidation and reduction take place respectively. Hydrogen ions are transported through the CCM that is not only the central enabler of the direct conversion of chemical energy into electrical energy; it also spatially separates the two gases (hydrogen and oxygen) from each other so that no oxyhydrogen gas is produced.
The central property of the CCM, that allows PEM fuel cells to generate electricity, is its semi-permeability: Only ions of a certain size can pass the membrane, in this case hydrolysed protons. Larger gas molecules, on the other hand, cannot get through.
So, as long as a fuel source is available and the individual components of the fuel cell are intact, it can reliably generate electricity.
Thanks to studies of the ageing processes in fuel cells, however, we know that even the smallest irregularities in the catalyst-coated membrane can have fatal consequences: They set a vicious circle in motion, at the end of which is the death of the fuel cell.
Small holes, superficial cracks or comparable irregularities in the delicate membrane, however, can significantly impair the chemical reaction taking place inside a fuel cell. This can impact the performance and lifetime of an entire fuel cell stack. Major damage could also have an impact on the safety of a fuel cell.
Studies of the ageing processes in fuel cells show that water – the by-product of the chemical reaction – is responsible for the ageing of the cell. It is not always present in the same quantity, as fuel cell cars, for example, produce different amounts of electricity when driving through the city.
The polymer membrane is exposed to the fluctuations of water content and humidity as well: The constant shrinking and swelling of the membrane gradually leads to deformation. Wave-like irregularities and weak spots in the coating are slowly developing. Over time, they turn into tiny holes and mark the beginning of the end of a fuel cell.
X-Ray images of degradation tests on membranes from the Paul Scherer Institute prove that the ageing process is taking place as described: From pinhole to sudden death: How fuel cells age.
If the process continues, the holes become larger, until eventually hydrogen molecules can migrate through the membrane (originally impermeable to gas molecules) and react with the oxygen at the cathode.
In the process, they form extremely reactive radicals that can react with the carbon chains in the polymer membrane and promote the inevitable corrosion.
Holes in the membrane grow wider, more gas molecules wander through the perforated membrane. More and more aggressive reactions produce more radicals and so on. At the end of the degradation process is the well-known combustion reaction of the oxyhydrogen mixture, which releases so much heat that the membrane melts.
Under normal conditions, these holes develop very slowly. Detecting mechanical damage that can accelerate the ageing process even before the MEA is installed in a fuel cell, can, of course, prevent a premature oxyhydrogen death and helps ensure the performance of the entire PEMFC stack in the long term.
Roll-to-roll processes for inline and offline quality testing will play a key role in the commercialisation of fuel cells in the automotive industry.
The material testing of the MEA assembly line can help save resources and significantly reduce the production costs of fuel cell manufacturing. At the same time, the efficiency and durability of the end product will increase.
Our MEA testing facility allows for the testing of membranes with different coating materials. In addition, it can be used in lithium ion battery manufacturing for electric vehicles. Read more about this below.
The facility makes it possible to inspect the membrane electrode assembly and the PEMFC for coating irregularities and mechanical damage that can reduce the service life and efficiency of the cell.
In the roll-to-roll-process, the surface of the membrane is scanned for irregularities in the catalyst coating on both sides employing a special camera system. It automatically distinguishes different types of anomalies such as pinholes or cracks in the micrometre range, categorised and codes them accordingly.
The greatest challenge for our top engineers was to ensure the particularly gentle and highly precise web handling of the extremely thin membrane with sensitive coating.
The current version of the test facility is a customised design for MEA material testing, that offers placeholders for further test procedures; among other things, an extension for measuring the coating thickness of a membrane could be easily integrated.
The testing facility has a much wider range of applications, though. It can also be used for product development in membrane manufacturing for pharmaceutical technologies in the medical sector, or for production tests in battery parts manufacturing.
With our test facility, we bridge the gap between research and industrial automation – a decisive contribution to optimising product development and fuel cell manufacturing.
The MEA testing system detects and marks superficial damage on the catalyst-coated membrane, enabling efficient material testing of the membrane-electrode assembly before further processing.
Thus, fuel cell and membrane manufacturers benefit from an efficiency gain thanks to smart product development and optimised manufacturing processes. Finally, they make their end customer happy by providing them with a high-quality, perfectly functioning fuel cell with a long lifetime happy - thanks to the roll-to-roll material testing facility of Printum Technology GmbH.
Lastly, customised solutions for material testing also gets battery production rolling, as the development of new materials for lithium-ion batteries requires similar testing procedures.
Coming to an end, there’s only one thing left to say, and that is: Long live the fuel cell (and the battery).
What is your opinion on this topic? We look forward to your feedback.
And if you are interested, we will be happy to provide you with more information on our systems and advise you with expert knowledge.