When it comes to electrolysis, the process of splitting water into hydrogen and oxygen using an electrical current, it’s important to have an effective gas diffusion layer. This is a layer that helps to evenly distribute the gases produced during electrolysis and enables the efficient operation of the electrolyzer.
So, how do gas diffusion layers work in electrolyzers? Here’s a breakdown:
- The gas diffusion layer is typically made of a porous material, such as carbon paper or carbon cloth. This material allows the gases produced during electrolysis to pass through and be distributed evenly.
- The gas diffusion layer is placed on top of the electrolyte, which is a substance that conducts electricity and enables the electrolysis reaction to occur.
- When the electrical current is applied to the electrolyzer, the water molecules are split into hydrogen and oxygen. These gases are then produced at the electrodes and pass through the gas diffusion layer.
- The gas diffusion layer helps to evenly distribute the gases and prevent any excess from accumulating in one area. This helps to ensure the efficient operation of the electrolyzer and allows for a continuous flow of gases.
- The gas diffusion layer also serves as a barrier between the gases and the electrodes. This helps to protect the electrodes from corrosion and prolong the lifespan of the electrolyzer.
Overall, gas diffusion layers play a crucial role in electrolyzers by helping to evenly distribute the gases produced during electrolysis and protect the electrodes from corrosion. By using an effective gas diffusion layer, you can optimize the performance of your electrolyzer and maximize its efficiency.
What are the various forms of Gas Diffusion layers
There are several forms of gas diffusion layers that can be used in fuel cells and electrolyzers:
Carbon paper
Carbon paper is made of thin sheets of carbon fibers that are bonded together with a resin. It is a common material used for gas diffusion layers because it is inexpensive and has good gas diffusion properties.
Carbon papers are used everywhere in PEMFC and DMFC and depending on the product properties they can be suitable for stationary devices, vehicles, and environments with different humidity values. A very common choice for Fuel cell vehicles, regardless of size. From drones to tractors and cars.
Carbon Plate
Carbon Plates are similar to carbon paper with the main difference being the dense and thick nature of these grades. It is what separates LINQCELL GDP from LINQCELL GDL Product line.
Carbon Plates, otherwise known as Molded graphite papers, are thick grades that are the product of choice for Electrolysers and distributed power generation. They have very low electrical resistance and a high degree of graphitization that increases, among others, the plates’ durability.
Carbon cloth
Carbon cloth is made of thicker, more closely woven carbon fibers. It is more durable and has a higher mechanical strength than carbon paper, making it a good choice for high-stress applications.
Carbon cloth is popular for PEMFC, PAFC, DMFC and also as an electrode for water electrolysis.
Non woven
Non woven is a an alternative to carbon papers. It is made by binding fibers together with hydroentanglement. This makes for a very flexible and compressible material that can easily come in roll form. Non woven can be applied to both stationary and motor driven fuel cells.
Metal mesh
Metal mesh is a fine-grained metal material that is used to form the gas diffusion layer. It is typically made of stainless steel or other corrosion-resistant metals and is known for its high strength and durability. Sintered titanium is the most commonly used metal.
Carbon papers, non woven and carbon fabric materials are the most cost effective products to use as gas diffusion layers. Sintered titanium, a very common and popular GDL, is very expensive and its price increases relative to its size. This is not the case with Carbon Plates such as LINQCELL GDL 1500 which are highly compressible, come in large dimensions and can be very flexible, efficient, and with a very long operating life.
Carbon Plates, when used as a gas diffusion layer, remain intact while the membrane needs to be changed or maintained.
There are many intricacies such as specification and tolerance requirements that cannot be covered in a single blog.
Contact us for help with choosing or manufacturing the gas diffusion layer you need.
