What is the Gas Diffusion Layer (GDL)?

The GDL is a porous structure made by weaving carbon fibers into a carbon cloth (e.g. GDL-CT and ELAT) or by pressing carbon fibers together into a carbon paper. Many of the standard GDLs that are produced today come with a Micro Porous layer (MPL) and hydrophobic treatment (PTFE). The MPL and PTFE help with the contact to the membrane and with water management. The MPL typically provides a smooth layer with plenty of surface area for catalyst and good contact with the membrane. The MPL often uses PTFE as a binder that increases hydrophobicity, which helps keep the water within the membrane from escaping – drying out the membrane and causing higher resistance (lower performance). There is often an additional PTFE coating on the MPL surface to further augment this.

What Exactly Does a Gas Diffusion Layer (GDL) Do?

GDL essentially acts as an electrode that facilitates diffusion of reactants across the catalyst layered membrane. The surface area and porosity of the GDL is what allows for the reactants in the channels of the bipolar plate to diffuse along the active area (catalyst area) of the membrane. With the increased surface area that the GDL provides, transportation of electricity from each individual catalyst site in the Membrane Electrode Assembly (MEA) to the current collectors increases.

The GDL is also the component that handles the fuel cell moisture control. It does this by consistently helping to remove the by-produced water outside of the catalyst layer and prevent flooding chambers. The GDL also helps keep some water on the catalyst layer surface to improve conductivity throughout the membrane. It is also important to note that the GDL allows for heat transfer during cell operation as well.

Comments

What is the CO2RR Gas Diffusion Flow Cell?

The CO2RR Gas Diffusion Flow Cell (CO2RR GDFC) is a type of electrochemical cell used in the conversion of carbon dioxide (CO2) to other chemicals through a process called the CO2 reduction reaction (CO2RR). It is similar in design to the Gas Diffusion Flow Cell (GDFC) used to measure gas permeability, but it is specifically designed to facilitate the electrochemical reduction of CO2. The CO2RR GDFC consists of a small, sealed chamber with two compartments separated by a thin, gas-permeable membrane. One compartment is filled with a CO2-containing gas mixture, while the other compartment contains an electrolyte solution and a catalyst material, such as copper or silver, which facilitates the CO2RR. The two compartments are separated by the gas-permeable membrane, which allows CO2 to diffuse from the high concentration compartment to the low concentration compartment. The CO2RR is driven by an electric potential applied across the two compartments, which induces the reduction of CO2 int...

How to Choose the Reference Electrode?

According to the test requirements, you can use the following content as a reference for selecting reference electrode. Different research systems can choose different reference electrodes: Neutral system: saturated calomel electrode or Ag/AgCl reference electrode Alkaline system: Hg/HgO reference electrode Acidic system: Hg/Hg2SO4 reference electrode Non-aqueous system: Non aqueous Ag+ reference electrode Compared with other reference electrodes, Ag/AgCl reference electrode is more sensitive to light.At the same time, the silver chloride electrode is also less affected by temperature than other types of reference electrode. If you choose calomel electrode, Hg2/HgSO4 electrode or Hg/HgO electrode, you can add a salt bridge under the electrode to protect the reference electrode and minimize the potential affected by temperature. Mercury Oxide Reference Electrode Hg/HgO PTFE Rod 6 * 60 mm is a good choice for the Alkaline system. you can find all the reference electrodes from ...

Ag AgCl Reference Electrode Silver Silver Chloride Φ6*140mm Glass Rod

In electrochemistry, in order for a specific reaction to occur, a stable electric potential needs to be applied to the working electrode. The potential of the working electrode should always be accurately controlled. This is why a reference electrode is needed as a potential reference standard. Common reference electrodes include Silver Silver Chloride Ag/AgCl reference electrode, saturated calomel electrode,Hg/HgO reference electrode, Hg/Hg2SO4 reference electrode and Non aqueous Ag+ reference electrode,etc. The silver-silver chloride (Ag/AgCl) electrode is the most commonly used reference electrode. Compared with calomel electrodes that use mercury and its salts, Ag/AgCl electrodes are more environmentally friendly. Its electrode potential also has sufficient stability, reliability and reproducibility. Special attention should be paid to maintenance and storage when using Ag/AgCl reference electrode. Before use rinse it with deionized water. If air bubbles are present around the poro...

Search This Blog