Hydrogen is fast emerging as a key sustainable fuel technology. Alleima’s Sanergy™ LT coating transforms the stainless steel used in hydrogen fuel cells into a surface that has the very high electrical conductivity needed for the most efficient energy production.
Electric vehicles and batteries have been the headline-grabbing fossil-free fuel technologies in recent years. However, hydrogen is also a crucial element for the transition into a sustainable future energy system because when it’s produced directly from water there are zero greenhouse gas emissions.
Fuel cells are converting the chemical energy of hydrogen into electricity that can be used in many different areas such as transportation, electric power supply, and electrical engines in general with many automotive companies putting significant focus and resources into developing hydrogen-powered vehicles.
According to research by Fortune Business Insights1 the global fuel cell market was valued at $4.58 billion in 2021, but is projected to grow by an incredible 30% a year, to reach $36.41 billion by 2029. Not bad for a technology first developed as far back as the 1830s!
However, a main challenge with developing high-performance fuel cells is the plates that are essential to withstand the harsh and demanding environment and still deliver excellent electrical conductivity. It’s quite a task to create bipolar plates (anode and cathode plates) that can combine tough requirements, including high electrical conductivity and corrosion resistance, in a single material. Further, to get this right and produce at a high volume with consistent quality is an additional challenge.
Alleima’s Sanergy™ LT coating offers solutions to these challenges. It transforms the stainless steel used in fuel cells into a material that can meet these stringent demands of conductivity and durability against corrosion, while also streamlining the production process.
The Sanergy™ LT coating is a graphite-like carbon nano-layer applied to stainless steel, typically type 316L, or in some cases, titanium strips. "The coating that we apply gives a stainless steel different surface properties that meet the very high electrical conductivity needed for a high-performance fuel cell,” explains Håkan Holmberg, Manager of Business Development Surface Technology StripTech at Alleima. He explains the key benefits of the coating:
It significantly reduces the electrical contact resistance, so there is an efficient transfer of electricity within the fuel cell.
It’s also a very durable coating, that protects the bipolar plates from the highly corrosive environment inside the fuel cell.
And, the coating thickness is monitored down to the nanometer level during production, which ensures consistency and optimal performance.
“The coated strip keeps the same mechanical properties as the stainless steel, which makes it suitable for forming and gives the plate and stack good mechanical stability,” he says.
Alleima’s focus on metallic plates for fuel cell bipolar plates has a strong emphasis on large-scale production. SanergyTM LT also addresses the issue of expensive plate production costs.
“We believe that eventually hundreds of millions of plates will be produced annually and that a pre-coated strip, produced by a continuous roll-to-roll process, is without a doubt the more cost- and time-efficient solution compared to stamp and then coat each individual plate as a separate operation,” says Holmberg.
“And here, Alleima’s continuous, roll-to-roll coating process is efficient and suitable for large production volumes. Our coils can be up to 10 km in length, and the pre-coated strip can be directly fed into the customer’s existing stamping tools rather than post-process each individual plate. Just imagine how many fuel cell bipolar plates can be produced from one single production coil!”
The ability of bipolar plates coated with Sanergy™ LT to make fuel cells more efficient has significant implications for decarbonizing transport and other industrial applications. After all, fuel cells utilizing hydrogen generated with fossil-free electricity directly from water do not emit greenhouse gases, aligning with the transition towards sustainable energy.
Key advantages of metallic plates include their suitability for high-volume production and thin profiles, making them ideal for space-limited applications such as automobiles. Here, fuel cell vehicles have zero CO2 emissions, meaning that they are a strong alternative to battery-electric vehicles, especially as they provide longer driving range and shorter refueling time.
“Not only that, Alleima is using a vacuum coating technology that is free from discharge to air or water, which also makes the production clean and energy efficient,” says Håkan Holmberg.
It’s no surprise then that Alleima is working closely with customers across various application areas in fuel cell development. Customers are at different stages of their programs, ranging from lab-scale research to full-scale mass production, but Holmberg confirms that progress is being made in applications for transportation, stationary heating, and electrolyzers.
We are also active within the field of green hydrogen production by so-called ‘water electrolysis’, where we expect huge market growth in the coming decade