The “CapS-PTL” project is developing an innovative technology for the production of porous titanium electrodes, which is crucial for efficient hydrogen production by electrolysis. By using capillary suspensions (CapS), precise control of the porosity and mechanical strength of the electrodes is achieved, which significantly increases electrochemical performance.
Efficient hydrogen production is essential for the energy transition. This is where the BMBF's DATIpilot innovation sprints program entitled "Defined porosity for hydrogen production with maximized efficiency" comes in. The project runs from 2024 to 2026.
The focus is on the production of porous titanium electrodes that are characterized by their defined porosity and mechanical strength. The cooperation between the Fraunhofer IWM and FastCast Ceramics GmbH combines innovative research with practical development in order to overcome technological hurdles. An important aspect of the project is the successful transfer of research results into industrial applications.
The aim of the project is to produce capillary suspensions (CapS) for the manufacture of porous titanium electrodes. These electrodes are crucial for improving the efficiency of water electrolysis, one of the most important processes for hydrogen production
This novel technology of capillary suspensions enables precise control of the porosity and mechanical strength of the electrodes, which makes a decisive contribution to increased electrochemical performance. The creation of a self-organized particle network also ensures high electrical conductivity.
The production of oil- and water-based capillary suspensions, which offer excellent electrical conductivity and pore structure, opens up new possibilities for the hydrogen economy and other industrial applications. These project results contribute to the sustainable energy transition and offer not only scientific but also economic prospects for success. Collaboration with industrial partners ensures the scalability and economic implementation of the developed technologies, paving the way for broad application.
In the project, two technological routes for the production of capillary suspensions are being developed using oil- and water-based CAPs.
The porosity and pore size can be specifically controlled with oil-based caps. At the same time, high electrical conductivity is achieved. With water-based caps, the drying and debinding process is significantly simplified. The stabilization of the suspensions poses the greatest challenge here. Adjusting the rheological properties is important in order to adapt the CapS to the respective processing parameters.
Various PTL materials are produced using liquid molding and investigated in terms of porosity and pore size. For industrial scaling, a prototypical thick-film PTL is produced and characterized in a test setup.
Once the material properties and proof of function have been set, PTLs are additively manufactured with targeted metastructuring. Additive manufacturing allows complex geometries and structuring to be realized and thus the functionality to be specifically adjusted.
Capillary suspensions are ternary material systems consisting of a solid particle phase, a main liquid and a small amount of an immiscible secondary liquid. This secondary liquid forms liquid bridges between the particles, creating a self-organized particle network. The capillary forces in this network ensure high mechanical strength and a high yield stress, which is used as a precursor for the porous sintered body.
The special features of the technology
The project was carried out with financial support from the Federal Ministry of Education and Research (BMBF) with the project partner FastCast Ceramics GmbH (funding code: 03DPS1179A).
Fraunhofer Institute for Mechanics of Materials IWM