back to top
My wish lists
Save your wish list
If you want to add more content to your wish list, simply log in. If you do not have a user account, please register for the Hanser Customer Center.

» Do you already have a user account? Please log in here.
» Don't have a user account yet? Please register here.
Your wish lists
If you want to use your wish list during your next visit, simply log in. If you do not have a user account, please register for the Hanser Customer Center.
» Do you already have a user account? Please log in here.
» Don't have a user account yet? Please register here.

« Back

Your advantages at a glance

  • One login for all Hanser portals
  • Individual home page for faster access to preferred content
  • Exclusive access to selected content
  • Personal wish lists on all portals
  • Central management of your personal information and newsletter subscriptions

Register now
Deutsch
Bookmark Bookmarked
07-11-2018

Proton-Conducting Membrane for Electrolysis and Fuel Cells

Fraunhofer IAP Is Researching New Electrochemical Processes

In order to use the technology of the electrolysis sustainably in the chemical industry or for the storage of renewable energies, technological advances are necessary. Using electrochemical processes for the production of base chemicals can reduce costs in the long term and link the energy system to chemical production. Usually, electrolyses use membranes to separate cathodes and anode space. These prevent the mixing of the two electrolytes. Such a membrane is either a microporous separator that allows all ions to pass through, or a selective anion or cation exchange membrane.

Looking through the proton-conducting membrane it shows how homogenous the membrane was fabricated (© Fraunhofer IAP)

Ion-conducting polymer membranes are an important component in the application fields of electrolysis and fuel cells. The aim of the researchers at the Fraunhofer IAP was to develop these membranes beyond the state of the art in order to use them, for example, for the decentralized, electrochemical production process of hydrogen peroxide.

The scientists developed a completely new development concept for the production of inexpensive and environmentally friendly ion-conducting membranes for the use in electrolysis and fuel cells.

It was an important goal within the development to increase the service life of the membranes, while at the same time maintaining performance and reducing costs. Previously used perfluorinated polymers, such as Nafion, have disadvantages: membranes based on these polymers are associated with high costs, lose their proton conductivity over time and frequently there are problems regarding oxidation stability. Also, the release of fluorine into the environment is probable. In high concentrations, fluorine is harmful to most living things, so preventing the release of fluorine is an important environmental factor.

Poly(phenlyquinoxaline) belong to the family of aromatic condensation polymers, which are characterized by a particular thermal and chemical stability. Based on this polymer class, new blockcopolypyphenylquinoxalines (BPPQs) were fabricated by polycondensation reactions. Subsequently, the polymers were sulfonated. The Fraunhofer researchers developed reproducible sulfonation conditions.

The fabricated sulfonated BPPQs have excellent solubility in organic solvents, for example, dimethylacetamide. These also show excellent thermal stability. Both properties are central to membrane fabrication.

Proton Conductivities Comparable to State of the Art

In addition to material development, the researchers’ focus was on optimizing and simplifying the membrane manufacturing process. The membranes can be produced on a laboratory scale and are mechanically very stable. In addition, they show a high oxidation stability.

Based on this material development and the membranes produced therefrom, it was possible to achieve comparable proton conductivities in the range of 1 mS/cm compatible with the state of the art. The fluorine concentration in the new polymers can be drastically reduced compared to the current benchmark Nafion (Nafion contains more than 70 percent fluorine, BPPQ about 5 percent fluorine).

Thus, a more environmentally friendly disposal of spent membranes is much easier possible. This will further reduce the cost of future processes using these novel membranes.

Company profile

Fraunhofer Inst.f. angewandte Polymerforschung IAP

Geiselbergstraße 69
DE 14476 Potsdam-Golm

Newsletter

Would you like to subscribe to our Newsletters on plastics technology and profit from the latest information?

Subscribe here

Subscribe here