Titanium Expanded mesh can also be applied to the electrolysis cell stack as part of the flow field or diffusion material, especially on the oxygen (anode) side, replacing the carbon-based gas diffusion layer (GDL) used in fuel cells. Our titanium mesh is made of expanded titanium that has been flattened and annealed, ensuring a smooth and flat surface suitable for electrochemical cell or fuel cell stacks. Although most commonly used on the anode side of the electrochemical cell, titanium stretched mesh is also often used on the cathode side of the electrochemical cell.
Why not use carbon-based gas diffusion layers in electrochemical cells?
In the presence of oxygen ions and voltage on the anode (oxygen) side of the electrochemical cell, the carbon-based GDL material will be consumed and converted to CO2 gas. This secondary reaction of oxidizing the carbon in the GDL temporarily reduces the electrolysis voltage, but it is a short-lived phenomenon. The carbon GDL is quickly consumed, resulting in poor compression in the stack, resulting in high resistance and low performance.
You can still use carbon cloth or carbon paper materials on the hydrogen side (cathode) because the presence of oxygen on that side will oxidize the GDL material.
Should platinum-coated titanium mesh be used?
Carbon-based GDL materials are consumed, untreated titanium is not, but the presence of oxygen affects titanium. Untreated titanium quickly forms an oxide coating (TiO2) in the presence of oxygen. This coating is an excellent insulator and therefore increases the resistance of the cell, reducing performance. However, this takes longer to become a problem than the oxidation of carbon GDL.
Oxidation of titanium can be prevented by gold or platinum plating of the titanium. Platinum plating is a very stable coating that also helps facilitate the electrolysis process, slightly increasing efficiency and significantly stabilizing performance.
Non-Ferrous Crucible Inc. supply three types of titanium mesh: weaved mesh, stamped mesh, and expanded mesh. Please contact us for more information.