TY  - JOUR
U1  - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed)
A1  - Schalenbach, Maximilian
A1  - Keller, Lilli
A1  - Janotta, Benjamin
A1  - Bauer, Alexander
A1  - Tempel, Hermann
A1  - Kungl, Hans
A1  - Bonnet, Martin
A1  - Eichel, Rüdiger-A.
T1  - The Effect of Ion Exchange Poisoning on the Ion Transport and Conduction in Polymer Electrolyte Membranes (PEMs) for Water Electrolysis
JF  - Journal of The Electrochemical Society
N2  - In water electrolyzers, polymer electrolyte membranes (PEMs) such as Nafion can accumulate cations stemming from salt impurities in the water supply, which leads to severe cell voltage increases. This combined experimental and computational study discusses the influence of sodium ion poisoning on the ionic conductivity of Nafion membranes and the ion transport in a thereon based water electrolysis cell. Conductivities of Nafion and aqueous solutions with the same amount of dissolved cations are measured with impedance spectroscopy and compared with respect to Nafion’s microstructure. The dynamic behavior of the voltage of a water electrolysis cell is characterized as a function of the sodium ion content and current density, showing the differences of the ion transport at alternating and direct currents. These experimental results are elucidated with a physical ion transport model for sodium ion poisoned Nafion membranes, which describes a proton depletion and sodium ion accumulation at the cathode. During proton depletion, the cathodic hydrogen evolution is maintained by the water reduction that forms hydroxide ions. Together with sodium ions from the membrane, the formed hydroxide ions can diffuse pairwise into the water supply, so that the membrane’s sodium ions can be at least partly be replaced with anodically formed protons.
KW  - Nafion
KW  - Water Electrolysis
KW  - Polymer Electrolyte Membrane
KW  - Nafion
KW  - Conductivity
KW  - Ion Transport
Y1  - 2022
UN  - https://nbn-resolving.org/urn:nbn:de:hbz:832-epub4-20477
SN  - 0013-4651
SS  - 0013-4651
SN  - 1945-7111
SS  - 1945-7111
U6  - https://doi.org/10.1149/1945-7111/ac9087
DO  - https://doi.org/10.1149/1945-7111/ac9087
VL  - 169
IS  - 9
SP  - 12
S1  - 12
PB  - IOP Publishing
ER  -