gdl role in electrolyzers

What is the role of GDLs in Electrolyzers

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.

About George Kountardas

George is a Jack of all trades with an unappeasable inquiring mind. Obsessed with new products and technologies, he is always pushing forward for better, faster and more efficient applications. Always learning something new.

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