High Density Graphite Impregnated And Machined Material

Impregnated plain and machined graphite plates for the highest electrical conductivity and highest current density to be used in fuel cell modules.

Each producer of raw graphite has its own specifications and formulations which are tailored for final application.

We select and test into pilot equipment the graphite which will give the best balance between electrical conductivity, resistance to corrosion, thermal and mechanical shocks.

Our “ultrafine grain” (down to 5µm size) with very high mechanical and thermal strength, high thermal conductivity withstand the harshest operating conditions.

Especially adapted for small series (< 30,000 pcs) with high freedom of geometry.

Impregnated Graphite

Impregnation of graphite will give imperviousness property. This process will not affect the electrical conductivity of the plate, as air from inner porosity is replaced by resin. On the contrary, some resins may bring improvement in electrical behavior on the long term due to protection from local sparks.

We are using proprietary resin and latest technology to ensure optimized properties. This process is not a coating but a deep penetration of resin into the open porosity of graphite microstructure.

Three grades of impregnated graphite, using two different resin types to cover most fuel cells applications.

Our GT-FLON and GT-OXY FLON show extraordinary corrosion properties outclassing traditional phenolic/epoxy/polyester resins impregnated graphite. Our plates could be used at much higher temperature and with longer lifetime that other materials on the market.

GT-KELITE+

GT-FLON

GT-OXYFLON

Applications

PEMFC

PEMFC with oxidative media

PEMFCVery oxidative media

Graphite grain size (mm)

0.043 - 0.005

0.020- 0.005

0.020- 0.005

Impregnant type

Epoxy Phenolic

Fluoropolymer

Fluoropolymer

Density

1.89

1.92

1.92

Flexural strength (MPa – ASTM C651)

43.0 - 50.0

32.0 - 42.0

32.0 - 42.0

Compression strength (MPa – ASTM C695)

118.0 - 159.0

91.0 - 130.0

91.0 - 130.0

Volume resistivity (Ω.cm) ASTM D257)

9.0-11.0

9.0-11.0

9.0-11.0

Max permissible material temperature (⁰C)

170

300

300

Recommended for

Traditional fuel cells conditions / MTBF 10- 20,000 hours

Frequent thermal cycling, high temperature. Oxidative media/long life time >MTBF 20,000 hours

Frequent thermal cycling, high temperature. Oxidative media/long life time >MTBF 50,000 hours

GT-FLON & GT-OXY FLON® for oxidative media & high temperature

We developed grades having exceptional corrosion, electrical and surface properties.

Unlike others PTFE impregnation, our material is impregnated to the core of the material and is not a superficial coating.

The penetration of fluoro resin around grain of graphite allow a very stable and long-term electrical properties. Our unique process brings exceptional corrosion and thermal resistance compared to traditional epoxy or phenolic resin impregnation.

We own a unique process of manufacture which allows to ensure the longest lifetime of bipolar plates in the market.

Machining and testing

  • We machine final products according to customer design.
  • Thickness of plates down to 0,5 mm.
  • Big dimensions available up to 700 x 400 mm
  • High precision machining and dimensional analysis
  • Big stock of raw material
  • Test according to customer requirement (permeability, corrosion, strength).
  • In-house laboratory for quality control and R&D