What is the Difference Between Carbon Paper and Carbon Cloth Based Gas Diffusion Layers (GDL)?

Carbon Paper versus Carbon Cloth Gas Diffusion Layers GDL

Carbon Paper Gas Diffusion Layers

Carbon Paper Gas Diffusion Layers (GDL) (e.g. Sigracet, Freudenberg, Toray, etc) tend to be thinner and more brittle than Carbon Cloth Gas Diffusion Layers (e.g. ELAT™, GDL-CT).  Each type has a different mass transport, porosity, hydrophobicity, and conductivity.  

Papers such as Toray are quite hard and brittle, with very little compressibility.  These are good for designs where a tighter tolerance is permitted in the compression and where the thin GDL is a critical factor.  Since they are so brittle, care must be taken when handling them in order to not break corners or otherwise damage the GDL.

There are a few other GDL’s  which are much more flexible (e.g. SigracetFreudenberg) and have a little more compressibility than Toray paper, which in turn makes them much easier to handle. They also do not chip or break as easily as Toray paper while still being available in thin sizes. Some GDLs are very hard and brittle with little compressibility (e.g. Toray); others are much more pliant/flexible but still don’t have much compressibility (e.g. Sigracet, Freudenberg).  Also, papers may or may not have Microporous Layers (MPL) and/or additional hydrophobic (Teflon) coatings.

 

Carbon Cloth Gas Diffusion Layers

The Carbon Cloth based GDL materials (e.g. GDL-CT, ELAT LT 1400) are the most flexible and are generally quite mechanically robust, but are also the thickest.  These are typically designed to have a fair amount of compression when assembled in the stack (anywhere from ~10% to 60% of the GDL thickness) and can act somewhat as compressible “springs” in the stack design.

We’ve put together a convenient table listing the properties of some of the more common GDL materials.  I hope it is useful in helping you make your selection.  Of course, you’re always welcome to AskUs@FuelCellsEtc.com if you need more specific guidance in your application.  There are many other GDL material types available as well (as custom options) that we are more than happy to assist you with as well.

Click here to visit our fuel cell store (Carbon Paper Gas Diffusion Layers and Carbon Cloth Gas Diffusion Layers).

 

Gas Diffusion Layer Comparison Table

Download the gas diffusion layer comparison table located below here. Click on the Gas Diffusion Layers (GDL) with red font to be directed to our online store and buy them today! If there is a GDL that you see that we do not have on our online store, contact us, and we will respond to you with a quotation in less than 24 hours.

 

*Toray paper, SpectraCarb, AvCarb and more will be available soon on our online store.  Contact us to reserve yours today!

Gas Diffusion LayerTypeThickness (um)Density (g/cm³)Basic Weight (g/m²)Air PermeabilityTP Resistance (mΩcm²)Tensile Strength (N/cm)Flexural Modulus (MPa)PorosityPTFE TreatedMPL
GDL-CTCloth410-180< 8 s< 13> 10 (MD) and > 5 (XD)--YesYes
Plain Carbon ClothCloth3561.5132--19.257.5-NoNo
ELAT LT 1400 WCloth4540.8025010 ml/(cm²-sec)---63%YesYes
Sigracet 10 BCPaper420-1351.45 cm³/(cm²*s)< 16--82%OptionalYes
Sigracet 24 BCPaper235-1000.6 cm³/(cm²*s)< 12--76%OptionalYes
Sigracet 25 BCPaper235-861 cm³/(cm²*s)< 12--80%OptionalYes
Sigracet 34 BCPaper315-1400.35 cm³/(cm²*s)< 14--75%OptionalYes
Sigracet 35 BCPaper325-1101.5 cm³/(cm²*s)< 15--80%OptionalYes
AvCarb GDS3215 EP40Paper2000.3060-< 14---YesYes
AvCarb GDS1120 P50Paper1840.3579-< 14.5---YesYes
AvCarb GDS2230 P75Paper2750.4098-< 14---YesYes
AvCarb MGL190Paper1900.44-2.2 s-654578%NoNo
AvCarb MGL 280Paper2800.44-3.3 s-854578%NoNo
AvCarb MGL 370Paper3700.46-4.4 s-1204578%NoNo
Freudenberg I2 C6Paper250-135-814--YesYes
Freudenberg C2Paper255-13570 s1016--NoYes
Freudenberg C4Paper255-13550 s812--NoYes
Freudenberg I2 C3Paper290-15035 s922--YesYes
Freudenberg I2 C6Paper250-13570 s814--YesYes
Freudenberg I2 C8Paper230-13590 s814--YesYes
Spectracarb 2050A-0850Paper2030.58835 cfm/ft²18420 MD & 260 XMD37-NoNo
Spectracarb 2050A-1550Paper3810.517535 cfm/ft²15-4078%NoNo
Toray Paper 030Paper1100.40--80 mΩcm-4080%OptionalNo
Toray Paper 060Paper1900.44--80 mΩcm504078%OptionalNo
Toray Paper 090Paper2800.44--80 mΩcm704078%OptionalNo
Toray Paper 120Paper3700.45--80 mΩcm904078%OptionalNo

Download the gas diffusion layer comparison table located above here.

 

Comments

  1. Becky Wong says:

    Hi, I would like to purchase a 10*20cm GDL-CT carbon cloth, what is the shipping fee to Hong Kong? Thank you.

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