TICOB

Currently, the structured bipolar plates, which along with the catalyst-coated membrane (CCM) and the porous transport layer (PTL) represent a central component within a proton exchange membrane water electrolysis stack, make up the largest cost item, accounting for a good half of the stack costs. This is mainly due to the high material costs of pure titanium and the manufacturing costs for the milled flow fields.

In the TiCoB project, novel titanium composite bipolar plates for PEM water electrolysers are to be developed and optimized, consisting of titanium powder as an additive in a polymer matrix. This should both significantly reduce the material costs of pure titanium and enable the typical structure of the BPP to be produced more cost-effectively. The complex process steps for structuring (milling, etching and polishing) with material loss should either be completely eliminated by the new material class or become comparatively easy due to good machinability.

Technical challenges are the lower specific conductivity and higher gas permeability of the composite material compared to titanium. The ISFH will focus on coatings for the titanium composite bipolar plate and modifications to the titanium powder to improve specific conductivity, contact capability and corrosion resistance. To this end, physical, electrochemical and general materials science investigations will be carried out on the composite material and the metallic phase, and rapid electrochemical tests will be performed on planar titanium composite BPPs with and without coating.

The knowledge gained will ultimately help to reduce hydrogen production costs in order to enable the technology to be widely used.