Equipment


In-Line Coater for Bipolar plates
— for fuel cells and electrolysers 
in-line - System i-L3.5000 

 

Although the coatings applied to the bipolar plates of fuel cells or electrolysers are very thin, they are a decisive cost factor in the production of these plates. For a bipolar plate for fuel cells with a size of around 750 cm², the cost of the coating should be in the low single-digit euro range per plate, depending on the layer and the system.
Simultaneous coating of both sides of a bipolar plate with typical dimensions of 500 mm x 150 mm requires a highly productive coating process and reliable coating technology. Several hundred individual bipolar plates are combined in one stack to form a fuel cell. It is obvious that the use of batch coating systems is not recommended for these quantities, as the productivity is far from sufficient. 
To maximize productivity, coating systems should operate in a continuous throughput mode. This means that only so-called in-line systems, in which substrates are coated on both sides at high throughput and without rotation, are suitable for such mass production.
Components for electrolysers such as electrode plates, PTLs (porous transport layers) or GDLs (gas diffusion layers) often require the use of in-line coating systems due to the size of the components.
In contrast to batch systems, these are multi-chamber systems in which the substrates are transported from chamber to chamber. The chambers are separated by large transfer valves, allowing various defined process steps to run separately in terms of space and time. This design enables a clean environment with consistent vacuum and process conditions.
 

PVT has developed two different in-line systems for the hydrogen industry. Various coating processes can be carried out in both systems, each with 4 or 3 vacuum chambers. The in-line systems are designed for smooth 24/7 operation.
Depending on customer requirements, magnetron sputtering, arc evaporation or PE-CVD (plasma-enhanced chemical vapor deposition) can be used as the coating process.
With the i-L 3.5000, the maximum substrate size is around 1.8 m x 1 m.
These in-line systems enable a considerable reduction in production costs. Depending on the materials applied, durable, robust and economically very attractive coatings are possible.
 

Bipolar plates are the essentials for the production and use of hydrogen. Fuel cells are the driving engine for a CO2-free future in transportation by cars, trucks, busses, planes, boats and ships. Bipolar plates are typically made from foils of stainless steel or titanium. They have to be coated to manage their con-ductivity (ICR*) and corrosion resistance. 
This is also valid for PTLs (porous transport layers) and GDLs (gas diffusion layers). 

Coating

In the past and for the future several different types of coatings got established or are under development and evaluation:
• Au (gold)
• Corrosion resistant metal coatings with noble metal top layer
• DLC (diamond-like-carbon in various compositions)
Such coatings can be deposited by PVD (physical vapor deposition) processes such as:
• HiPIMS (high power impulse magnetron sputtering)
• DC- magnetron sputtering
• Arc evaporation

Coating equipment

Even though the coatings deposited onto the bipolar plates are very thin,  cost are the driving factor for coating the plates. 
Since both sides of a bipolar plate have to be coated a highly productive coating process and coating equipment are essential.
 
Around 300 and more bipolar plates are compiled in one fuel cell stack for one single drive unit. 

At these numbers batch type coating systems are noption, since productivity is by far too low.

Systems have to operate in a continuous way, i.e. for mass production of such components the so-called in-line systems are the only option to coat substrates with high throughput from both sides at the same time without rotation.
While the substrates are carried from chamber to chamber separated by large transfer valves the different process steps are carried out in dedicated chambers.The process chambers guarantee a clean environment at very stable vacuum conditions.
PVT developed for this application 2 different types of in-line systems:
• the i-L 3.5000 and 
• the i-L 4.3500   Coating equipment           
The i-L 3.5000 is in its basic configuration a 3 – chamber  in-line system where most different coating structures can be deposited by HiPIMS and magnetron sputtering.
The i-L 3.5000 is a coating system which can coat up to  2.000.000 bipolar plates per year. By adding another process chamber the productivity can be significantly increased.
The substrate carrier has a dimension of 1.8 x 1m, i.e. 4 pieces electrolyser plates of 1.8 x 0.5 m can be coated single sided on one such frame.
i-L 3.5000 is designed to coat planar large area substrates, i.e.the transport frame carrying the substrates can hold substrates up to a planar surface of close to 2 m² and up to50mm in the 3rd dimension.Such substrates can be besides bipolar plates for fuel cells and electrolysers, mirrors, stapled razor blades and cutters, and many other items.Coating equipment 

* ICR = Contact Resistance

Our Service for you

PVT offers you for your H2 – applications:
• the development of coating processes
• the development of coatings
• Coating samples up to 1.800 x 1.000 mm in size of your own coatings or of our high-performance coatings.
• Coating service as Start-up production of your parts · Highly productive in-line coating systems