Titanium Fiber Felt with Microporous Layer, 0.4mm

Estimated to ship on Jun 7th. 

Titanium Fiber Felt with Microporous Layer (MPL) is a novel metallic diffusion layer that mimics the carbon-based gas diffusion layer with MPL for its microstructure.  Ti fiber felt section forms the macroporous side and MPL section of this product forms the front face facing membrane for its microstructure, density, and low roughness.  Sintered Ti fiber felt section is made of Grade 2 Titanium fibrous (fine wires with small diameter) and has a continuous three-dimensional mesh structure. MPL section is made from sintered Ti particles in a more dense form and a much better surface roughness in order to establish good electrical contact and porosity gradient from the MPL side to the back felt side, similar to carbon based gas diffusion layers with MPL used in the PEM fuel cells.

The following SEM images show both Ti fiber felt side and MPL side of this product that clearly demonstrates the difference in surface roughness and thus contact area and resistance. 

While titanium based fiber felts (with or without MPL) are predominantly used in PEM electrolyzers as the metallic diffusion layers, anion exchange membrane water electrolyzers (AEMWE) can greatly benefit from the use of titanium based metallic diffusion layers since the concentration of the alkaline electrolytes (such as NaOH or KOH) in AEMWE systems is in the range of 0-1 Molar. With such low concentrations, titanium fiber felt with MPL is expected to work great because of its chemical stability. For further stability and corrosion protection, this product can also be platinized using the methods available in the literature to further improve the longevity.

PEM electrolyzer cells with solid acid membranes such as Nafion, Aquivion, and any other perfluorosulfonic acid (PFSA) membranes and alkaline electrolyzers with anion exchange membranes can utilize titanium fiber felt with MPL as the anode and cathode diffusion layer. Furthermore, the pristine titanium fiber felt with MPL can also be catalyst coated with the appropriate anode and cathode catalyst in order to be used as the anode and/or cathode electrodes. This catalyst coating can also be implemented on the platinized Titanium fiber felt with MPL in order to improve the longevity aspect for highly demanding applications.

Key Applications in PEM/AEM Electrolyzers:

• Porous Transport Layer (PTL): Acts as the vital interface between the anode and cathode catalysts and their respective flow fields, transporting electrons, distributing reactants, and removing gases.
• Current Collector: Provides an excellent conductive pathway for electrons from the external power source to the electrodes of the electrochemical cell.
• Catalyst Support: Its high surface area makes the titanium fiber felt with MPL to be suitable for coating with the respective hydrogen evolution reaction (HER) and Oxygen evolution reaction (OER) electrocatalyst by using the commercially available deposition methods. 

Product specifications:

·       Thickness: 400 micrometers (75micron MPL + 325micron fiber felt layer)

·       Porosity: ~ 50 % (30% for the microporous layer and 55% for the fiber felt layer)

·       Tensile Strength: >85 MPa

·       Bending Strength: >45 MPa

·       Compression Ratio @ 3MPa: <5%

·       Effective Contact Area: >50%

·       Contact Resistance: ~6 milliOhm.cm2

·       Roughness: ~5 micrometers

Standard availability is 10×10 cm and 20×20 cm sheet. Please let us know if you want different sizes or other requests at info@electrohy.com