3 Benefits of Wire Mesh for Electrolyzers & Fuel Cells
The demand for new renewable energy sources is giving rise to new-generation fuel cell development and hydrogen production using electrolyzers. Within this sector, wire mesh is one small component of the larger whole, but the right selection plays a critical role in the overall performance of the specified application. So, what exactly is its function, and what are its advantages?
More and more countries need new energy sources to combat climate change, increase energy security and create new sources. The goal is to rely less on traditional energy sources like fossil fuels and focus on developing more sustainable, cleaner, and efficient energy.
Hydrogen is considered a clean and versatile energy carrier because it can be produced from a variety of sources and creates electricity without emitting harmful pollutants. As the demand for hydrogen energy grows, so does the demand for products and processes that produce it, such as electrolyzers. Fuel cells powered by hydrogen are also increasing in demand. When used with green hydrogen fuel cells can generate very clean electricity, with only water as a byproduct.
To understand where wire mesh fits into electrolyzers and fuel cells, here’s a brief overview of each.
What Are Electrolyzers?
Electrolyzers produce hydrogen gas by splitting water molecules into hydrogen and oxygen. The process is called electrolysis, in which an electric current is passed through a liquid or a solution containing ions, causing a chemical reaction.
The most common types of electrolyzers include:
- Proton exchange membrane (PEM)
- Alkaline (AEL)
- Solid oxide (SOEL)
- Anion exchange membrane (AEM)
What Are Fuel Cells?
A fuel cell uses hydrogen as the fuel source and oxygen as an oxidant, and as a result of an electrochemical reaction, it produces electricity and water as a byproduct.
The main types of fuel cells include:
- Polymer electron membrane (PEMFC)
- Solid oxide (SOFC)
- Alkaline (AFC)
- Molten carbonate (MCFC
- Phosphoric acid (PAFC)
- Direct methanol (DMFC)
Electrolyzers and fuel cells are complex devices that are designed with different components and materials. Here’s how wire mesh can fit into the design.
How Wire Mesh Can Be Used in Fuel Cells & Electrolyzers
You can use wire mesh in various functions within the sub-components of a fuel cell or electrolyzer, including:
- Gas diffusion layer (GDL) or porous transport layer (PTL)
- Gas diffusion electrode (GDE)
- Membrane electrode assembly (MEA)
- MEA stack
- Cell stack
Within the sub-components, woven wire mesh (and other types of media) can perform one or more of the following functions, depending on the design and electrochemical makeup of the cell:
- Current collector
- Electrode enhancer
- Gas diffusion/dispersion
- Catalyst anchor
- Electrolyte substrate/slurry anchor
An infinite number of combinations of wire diameter, weave, and mesh count mean that different specifications of woven wire mesh are suitable for performing these different functions. The electrochemical engineer’s design of the cell and the chemical reactions within the cell will ultimately impact which alloy (most often nickel or titanium) is required, and whether the wire mesh requires plating or coating with titanium, platinum, silver, or other metals. But why should you consider wire mesh over other media? Here are three benefits of selecting wire mesh.
3 Benefits of Wire Mesh for Electrolyzers & Fuel Cells
1. Interchangeable Parameters
Woven wire mesh is a versatile component. Depending on the function that the wire mesh needs to perform, you can specify the parameters to meet the specific requirements of your fuel cell or electrolyzer application. This versatility lends a key benefit: the ability to interchange parameters, such as porosity and surface area, to find the optimal solution.
Porosity refers to the amount of open space in a material. In the case of wire mesh, it’s the percentage of the total volume of the wire cloth occupied by the openings or pores of the mesh. By changing the parameters of the wire mesh, such as the wire diameter, spacing, and weave pattern, you can adjust the porosity to a specific level. This allows for greater control over the flow of gas through the electrode structure, which can help to improve the efficiency and performance of the fuel cell or electrolyzer.
Surface area is another essential parameter you can adjust using wire mesh. Surface area refers to the active material available for the electrochemical reaction. Wire mesh can help increase the surface area by providing a high-density, three-dimensional network of wires that can support a large amount of catalyst or slurry material. This increased surface area can lead to higher reaction rates and improved efficiency.
If the mesh is to support the catalyst or electrolyte substrate, the specification to hold the slurry within the mesh structure (requiring a more open form) will be entirely different from the specification for when the slurry needs to lay on top of it (much greater surface area).
The unique thing about woven wire mesh is that these specifications can act independently of each other, so you can achieve a high surface area with varying porosities, depending on your needs and cost requirements. The same can’t be said of other media such as expanded metal because changing one parameter directly impacts the other.
2. Greater Flexibility
Wire mesh provides both a level of flexure that other materials can’t and the ability to keep its shape, which is beneficial for both fuel cells and electrolyzers.
The wire mesh provides a distinct advantage due to its unique “peaks,” which provide added depth that can penetrate deeper into the application and withstand significant flex without losing contact with the active materials. This feature makes wire mesh a highly reliable and durable material for fuel cell and electrolyzer components, providing consistent and repeatable performance.
3. Increased Conductivity
Wire mesh involves a network of interconnected wires, which allows for the efficient flow of electrons through the material. This conductivity is essential in electrochemical cells because it facilitates the chemical reactions that produce or consume hydrogen.
There are some processes that control the thickness (or depth) of wire mesh; especially important if the mesh in the stack has tight tolerances. In addition, these processes also help stabilize the mesh and provide superior conductivity contact between surfaces.
One such process is called Cold Bond™. Pioneered by the engineers at Gerard Daniel over 20 years ago, Cold Bond™ mechanically locks the weave together (like calendaring) to stabilize the pore structure and edges. It also achieves some metallic bonding between interfacing surfaces, so all parts of the mesh maintain full electrical continuity (like sintering).
When conductivity is a priority, wire mesh performs better than carbon cloth or paper. This is because wire mesh is more mechanically stable and durable than carbon cloth, which fails to retain its shape, causing the connection points to constantly shift. Wire mesh is less likely to deform or break under the high pressure or temperature conditions that can be present in these applications. The Cold Bond™ process enhances this further because the metallic bonding provides repeatability and consistency that can sometimes be a challenge with carbon paper or cloth.
Renewable energy is increasingly important as more energy companies look for new energy sources, and fuel cells and electrolyzers present a great opportunity.
For certain functions across both products, wire mesh is a great material option. Its shape, porosity, and bonding process make it a very controllable and repeatable product for new energy applications.
Although woven wire mesh provides excellent value, other media may be a better fit, based on the design of the cell. Expanded metal, carbon cloth and paper, sintered random fiber and felt are some of the other options used. No matter what your requirements are, partner with a trusted supplier that can help you source the right material to meet your specifications.
Gerard Daniel Expertise
Gerard Daniel has been a leading provider of wire mesh and other media for 70 years, with 20 years of experience working in the electrochemical battery, fuel cell, and most recently electrolyzer, market segments. Underpinning the widest range of inventory in North America, our team of skilled application engineers applies their vast knowledge of woven mesh and components to develop the most efficient solution that aligns with your design, development, and production needs, ultimately resulting in reduced manufacturing costs. If you’re interested in learning more about our capabilities, please contact us.