Projects

3D-PakT - 3D printing of porous catalytically active transport layers

A sustainable energy and mobility infrastructure based on hydrogen as an energy carrier can only work if hydrogen is provided by water electrolysis powered by renewable energy sources.

Proton exchange membrane (PEM) water electrolysis is an ideal candidate, due to its advantages such as high flexibility, high achievable current densities, technically simple process engineering and high hydrogen purity.  However, this is offset by high material and manufacturing costs, especially for the oxygen-generating electrode, where harsh reaction conditions prevail.

Testing the electrical conductivity of an additively manufactured PTL grid structure
© Fraunhofer ICT
Testing the electrical conductivity of an additively manufactured PTL grid structure

As part of the 3D-PakT project, Fraunhofer ICT is conducting research into new multifunctional porous transport layers (PTLs). The new PTLs are used in the PEM electrolyzer to transport water to the electrode and the generated oxygen out of the cell. At the same time, PTLs establish electrical contact between the catalyst layer on the proton exchange membrane and the current conductor to the energy source. To date, PTLs have been made of titanium. In 3D-PakT, the focus is on research into electrically and ionically conductive polymer compounds for PTLs and their processing using additive manufacturing (3D printing).

 

The base polymer used to produce the polymer compounds is quite expensive. To work with low material quantities, a 9 mm mini twin screw extruder with a configurable co-rotating twin screw pair and an exchangeable, individually configured L/D 40:1 barrel is used.
© Fraunhofer ICT
The base polymer used to produce the polymer compounds is quite expensive. To work with low material quantities, a 9 mm mini twin screw extruder with a configurable co-rotating twin screw pair and an exchangeable, individually configured L/D 40:1 barrel is used.
Concept of the new multifunctional porous transport layer made of an electrically and ionically conductive plastic compound for proton exchange membrane water electrolysis
© Fraunhofer ICT
Concept of the new multifunctional porous transport layer made of an electrically and ionically conductive plastic compound for proton exchange membrane water electrolysis