Method for operating a fuel cell, polymer electrolyte membrane fuel cell which works with the method and process for producing the fuel cell

A polymer electrolyte membrane (PEM) fuel cell, comprising:

• a membrane electrode assembly;
• a bipolar plate;
• and
• an intermediate layer of sufficient electrical conductivity disposed between said membrane electrode assembly and said bipolar plate, said intermediate layer formed by a hydrophobized carbon structure selected from the group consisting of hydrophobized carbon papers each with different porosities and hydrophobized carbon sheets each with different porosities, said intermediate layer containing said hydrophobized carbon papers becoming increasingly hydrophobic and having increasingly fine pores as a proximity to said bipolar plate increases.

A polymer electrolyte membrane fuel cell, comprising:

• a membrane electrode assembly;
• a bipolar plate;
• and
• an intermediate layer of sufficient electrical conductivity disposed between said membrane electrode assembly and said bipolar plate, said intermediate layer being a coating formed of carbon paper with a carbon/TEFLON mixture.

A polymer electrolyte membrane (PEM) fuel cell, comprising:

• a membrane electrode assembly;
• a bipolar plate;
• and
• an intermediate layer of sufficient electrical conductivity disposed between said membrane electrode assembly and said bipolar plate, said intermediate layer being a coating disposed on said bipolar plate and formed of a carbon/TEFLON mixture.

A polymer electrolyte membrane (PEM) fuel cell, comprising:

• a membrane electrode assembly (MEA);
• a bipolar plate;
• and
• an intermediate layer of sufficient electrical conductivity disposed between said membrane electrode assembly and said bipolar plate, said intermediate layer is a two-layered structured formed of a hydrophobized sheet and a carbon layer having a predetermined porosity.

A process for producing a fuel cell, which comprises the steps of:

• providing a membrane electrode assembly and a bipolar plate;
• building up an intermediate layer selected from the group consisting of hydrophobized carbon papers coated at least with carbon of a predetermined porosity and a hydrophobized sheet coated at least with carbon of a predetermined porosity;
• introducing the intermediate layer having sufficient electrical conductivity between the membrane electrode assembly and the bipolar plate;
• and
• coating at least one of the hydrophobized carbon papers and the bipolar plate with a carbon/TEFLON mixture.

A polymer electrolyte membrane (PEM) high-temperature fuel cell, comprising:

• a membrane electrode assembly;
• a bipolar plate;
• and
• an intermediate layer of sufficient electrical conductivity disposed between said membrane electrode assembly and said bipolar plate, said intermediate layer formed by a hydrophobized carbon structure selected from the group consisting of hydrophobized carbon papers each with different porosities and hydrophobized carbon sheets with different porosities, said intermediate layer containing said hydrophobized carbon structure becoming increasingly hydrophobic and having increasingly fine pores as a proximity to said bipolar plate increases.