4:25 PM - *EN10.04.02
Spatially Resolved Analysis of Degradation in Polymer Electrolyte Fuel Cells and Novel Electrode Designs for Improved Efficiency of Polymer Electrolyte Water Electrolysis
Severin Vierrath1,Matthias Breitwieser1
Fuel cells and electrolysis based on a polymer electrolyte membrane (PEM) are key technologies for a hydrogen society to produce green hydrogen, store large amounts of energy or electrify heavy-duty vehicles. However, durability and efficiency of the membrane electrode assembly is still a major focus of research. This talk gives two examples on investigating ageing phenomena in a fuel cell electrode. The first examines carbon corrosion in the electrode via Focused-Ion-Beam (FIB) tomography, showing that the major mechanism of this degradation phenomenon is loss of active catalyst . In the second investigation, the polymer degradation in the membrane is studied via Raman, showing that the polymer degradation is favored on the anode side .
The second part of the talk deals with reducing the iridium catalyst loading in the anode of PEM water electrolysis. In the effort of reducing the catalyst, a major problem arises in the in-plane conductivity of the electrode, which leads to poor efficiencies . Two alternatives are presented, which counter this problem by increasing the electrical conductivity. Employing a nanofiber interlayer enabled an 80% reduction of catalyst material without compromising efficiency or durability. In the second more simplistic approach, blending the polymeric binder in the electrode with PEDOT:PSS, an electronically conductive polymer, yielded a similar effect .
 Hegge, F., Sharman, J., Moroni, R., Thiele, S., Zengerle, R., Breitwieser, M., & Vierrath, S. (2019). Impact of Carbon Support Corrosion on Performance Losses in Polymer Electrolyte Membrane Fuel Cells. Journal of The Electrochemical Society, 166(13), F956.
 Böhm, T., Moroni, R., Breitwieser, M., Thiele, S., & Vierrath, S. (2019). Spatially resolved quantification of ionomer degradation in fuel cells by confocal Raman microscopy. Journal of The Electrochemical Society, 166(7), F3044.
 Bernt, M., Siebel, A., & Gasteiger, H. A. (2018). Analysis of voltage losses in PEM water electrolyzers with low platinum group metal loadings. Journal of the Electrochemical Society, 165(5), F305.
 Hegge, F., Lombeck, F., Cruz Ortiz, E., Bohn, L., von Holst, M., Kroschel, M., ... & Vierrath, S. (2020). Efficient and Stable Low Iridium Loaded Anodes for PEM Water Electrolysis Made Possible by Nanofiber Interlayers. ACS Applied Energy Materials.
 Ortiz, E. C., Hegge, F., Breitwieser, M., & Vierrath, S. (2020). Improving the performance of proton exchange membrane water electrolyzers with low Ir-loaded anodes by adding PEDOT: PSS as electrically conductive binder. RSC Advances, 10(62), 37923-37927.