Hydrogen Fuel Cells
Contamination removal in hydrogen fuel cell production
HFC technology will be an essential part of zero carbon emissions solutions. It is very clean compared to internal combustion engines with the output by-product being H2O. HFCs are likely to be paired with battery technology but are forecast to be supplied in smaller volumes into passenger automotive sector and more significantly into heavy goods vehicles, buses, shipping, material handling and even aircrafts and drones.
While it has been slower to evolve and scale-up than battery technology, it is now being actively industrialised with a focus on improved automation of key process stages.
Meech has been engaging with scale-up partners in industrialising the production processes of PEM fuel cells (proton exchange membrane) which is most commonly being adopted in the automotive sector. It is essential to avoid embedded contamination and high static charge in the cell components and Meech will work with our partners to determine the optimise solution based on available space on machine, type and characteristics of contamination and process environment. By avoiding these risks, production speeds can be optimised, yields can be maximised, and latent defects can be avoided.
Our Zero Faults Forward Approach
We have identified a number of processes within hydrogen fuel cell manufacturing that are prone to contamination on the line. By applying the right solutions at these points, you make sure there are no weak links to your production chain. We explore these below and demonstrate our solutions…
What is a Hydrogen fuel cell?
Fuel cells are devices that generate electricity through “electrochemical redox reactions” (not combustion – they don’t burn anything).
In short, they convert chemical energy of fuels (hydrogen or methane) directly into electrical energy (by combining them with oxygen). As the chemical conversion does not need thermal and mechanical energy first fuel cells are (by comparison) extremely efficient. Besides minimizing energy losses, fuel cells are also far less polluting than classic combustion engines with carbon emissions being much lower and non-toxic.
If “green” hydrogen (hydrogen created using renewable energy sources) is fuelling the cell, they only emit water vapour and warm air! Delivering overall a very clean power solution.
Complementary technologies
Fuel cells and batteries are two viable solutions to create electric powertrains and thus address the clean energy challenge. Both technologies will also have their place as a hybrid solution (combined). Depending on the application, either can be the best answer.. (we will also see them in combination)
Main differences
The single most essential difference between fuel cells and batteries is simple: a battery stores energy which it then uses, whereas a fuel cell generates energy by converting available fuel. As long as you have access to the fuel, you have access to electricity – anytime, anywhere. Interestingly, a fuel cell can also have a battery component to store the energy it is generating.
Meech has been engaging with scale-up partners in industrialising the production processes of battery cells and PEM fuel cells (proton exchange membrane) which is most commonly being adopted in the automotive sector. It is essential to avoid embedded contamination and high static charge in the cell components and Meech will work with our partners to determine the optimise solution based on available space on machine, type and characteristics of contamination and process environment. By avoiding these risks, production speeds can be optimised, yields can be maximised, and latent defects can be avoided.
primary components of the hydrogen fuel cell
Bi-Polar Plates
Bi-polar plates are designed to channel hydrogen, conduct electrons and dissipate heat from the cell:
Micro Porous Carbon Paper or Non-Woven Material
Micro porous carbon paper or non-woven material is designed to ensure there is a consistent flow and transfer of active media across the membrane:
Catalyst Coated Membrane (CCM)
A critical part of PEM fuel cell membrane is the CCM (catalyst coated membrane). This is a polymer membrane coated with anode and cathode on either side. When automating key production stages of this component in a roll-to-roll converting format, it is critical to eliminate static charges and avoid embedded contamination so the final CCM component is fully optimised and not rejected or carried forwards with a latent defects.
Primary applications: Catalyst coated membrane production
Dry Coating Stage on to Carrier Film
In the first stage, the Anode and Cathode coating material is separately coated onto a ‘carrier’ PTFE or PE carrier film (before being dried and then transferred on to each side of a single moisture sensitive polymer membrane).
Anode and Cathode carrier rolls are produced separately.
Referring to the image above, prior to coating, the carrier film must be free of contamination and neutralised of static charge (created upstream and during unwind process) – ensuring coating accuracy and stability is maintained and materials flow through converting process without difficulties.
It may also be required to clean the coating roller to help maintain a consistent calliper of coating.
As the coating layer is dried, heat related crystals can be generated from the carrier film (on underside) and this requires a specialist contact type removal process to prevent membrane damage or cross-contamination to other components.
The anode or cathode roll is then transferred to the next production stage (with zero faults carried forwards).
A combination of non-contact and contact type web cleaners are recommended – all Meech web cleaners include static ionisation bars to neutralise materials.
Several essential cleaning and static control processes are required to avoid embedded contamination and high static charge build up as shown in the above diagram.
Other critical processes exist which are being investigated as the industry increasingly adopts automation techniques.
It is also possible that live performance monitoring and date logging is needed for more critical static control solutions.
If you are designing a pilot or scaled up battery production line or have existing contamination or static charge related challenges, please get in touch with one of our Meech industry experts.
(See bottom of page for frequently required solutions).
Coating Transfer Stage onto Polymer Membrane
In the next stage, separate rolls of cathode coated and anode coated carrier films are unwound with the dry anode and cathode catalyst coatings facing towards polymer membrane.
Through a combination of compression and heat the “decal” anode and cathode coating is transferred onto each side of the polymer membrane.
The catalyst coated membrane (CCM) is then wound into a roll for next process stage.
Several essential cleaning and static control processes are required to avoid embedded contamination and high static charge build up as shown in the above diagram.
Other critical processes exist which are being investigated as the industry increasingly adopts automation techniques.
It is also possible that live performance monitoring and date logging is needed for more critical static control solutions.
If you are designing a pilot or scaled up battery production line or have existing contamination or static charge related challenges, please get in touch with one of our Meech industry experts.
(See bottom of page for frequently required solutions).
* All drawings are for illustrative purposes only. The position of the static control and web cleaning solutions most suitable for your process will depend on certain factors of your application.
Web Cleaning Solutions
Meech is a leading Web Cleaning manufacturer with a comprehensive range of four systems. Each system is based on a different cleaning principle, this uniquely allows us to provide our customers with a system best suited for their application. All Meech systems incorporate the latest shockless AC static control bars as standard which is crucial for comprehensive contamination removal. Meech has more than 200 successful web cleaning installations in a range of industries including Packaging, Printing and Converting.
Static Control Solutions
Meech is a market leader in manufacturing and supplying static control products since the 1960’s; offering a wide range of electrostatic products that provide anti-static and ESD protection and measurement, static generation, electrostatic control and elimination.
Could we help improve your hydrogen fuel cell manufacturing process?
