Titanium Fiber Felt in Gas Diffusion Layer of PEMEC

The gas diffusion layer (GDL) is a key component in the proton exchange membrane electrolysis cell (PEMEC), which is located between the catalytic layer and the current field with many functions. To ensure minimum voltage, current, heat, interface and fluid loss, it must have characteristics such as electrical conductivity, thermal conductivity, corrosion resistance performance, high porosity and high permeability in order to efficiently transfer electrons, heat and reactants/products between the catalyst layer and the current field.

Titanium fiber felt, an excellent diffusion layer material that meets these requirements, is made of titanium fiber and has a porosity of more than 70%, providing ample space for the reaction. Our titanium fiber felt is manufactured with advanced technology, which can meet the needs of different applications and improve the performance and service life of hydrogen production in PEMEC.

Specifications of Titanium Fiber Felt:

• Material: Titanium (various grades for choice)
• Porosity: 60% – 75% (variable)
• Surface treatment: Platinized and iridium oxide coated
• Shape: Round disc, sheet, tube, round bar, cap, etc.
• Size: 1500 mm, 1200 mm (Customizable)
• Thickness: 0.25 mm, 0.40 mm, 0.60 mm, 0.80 mm, 1.00 mm (Customizable)

Titanium Sintered Felt Plates

What is the main functions of GDL in PEMEC?

• Ensure uniform distribution of reactive gases on electrode surface;
• Structurally help the stack withstand the extension caused by water absorbency;
• Aid with heat transfer, electrical surface conductivity, and removal of excess water from electrodes that is produced by redox reactions;
• Clear the path for the fuel and the oxidizing agent towards the catalyst layers.

Where can the GDL be used?

• Proton exchange membrane (PEM) stacks
• Direct methanol (DMFC) stacks
• Phosphoric acid (PAFC) stacks
• Electrolyzers
• Redox flow batteries
• Other electrochemical devices

Requirements for GDL in PEMEC:

• In PEMECs, this thin, porous component requires the material to be of high electrical and thermal conductivity and chemical/corrosion resistance performance, as it acts as the layer controlling the proper flow of reactant gases (hydrogen and air) and managing the water transport in and out of the membrane electrode assembly (MEA).
• It also requires high strength to support external forces from the assembly, and does not deform into the bi-component plate channels to restrict flow. Porosity, pore distribution and pore volume are important parameters for measuring the pore structure of GDL.

Considering the above information, titanium fiber felt has received considerable attention as a highly promising material for PEMEC due to its high corrosion resistance at high positive overpotential, even in highly acidic and humid conditions. In addition, titanium provides high thermal conductivity, high electrical conductivity and excellent mechanical properties.