TY  - JOUR
AU  - Hopfenmüller, Bernhard
AU  - Zorn, Reiner
AU  - Holderer, Olaf
AU  - Ivanova, Oxana
AU  - Lehnert, Werner
AU  - Lüke, Wiebke
AU  - Ehlers, Georg
AU  - Jalarvo, Niina
AU  - Schneider, Gerald J.
AU  - Monkenbusch, Michael
AU  - Richter, Dieter
TI  - Fractal diffusion in high temperature polymer electrolyte fuel cell membranes
JO  - The journal of chemical physics
VL  - 148
IS  - 20
SN  - 1089-7690
CY  - Melville, NY
PB  - American Institute of Physics
M1  - FZJ-2018-03242
SP  - 204906 -
PY  - 2018
AB  - The performance of fuel cells depends largely on the proton diffusion in the proton conducting membrane, the core of a fuel cell. High temperature polymer electrolyte fuel cells are based on a polymer membrane swollen with phosphoric acid as the electrolyte, where proton conduction takes place. We studied the proton diffusion in such membranes with neutron scattering techniques which are especially sensitive to the proton contribution. Time of flight spectroscopy and backscattering spectroscopy have been combined to cover a broad dynamic range. In order to selectively observe the diffusion of protons potentially contributing to the ion conductivity, two samples were prepared, where in one of the samples the phosphoric acid was used with hydrogen replaced by deuterium. The scattering data from the two samples were subtracted in a suitable way after measurement. Thereby subdiffusive behavior of the proton diffusion has been observed and interpreted in terms of a model of fractal diffusion. For this purpose, a scattering function for fractal diffusion has been developed. The fractal diffusion dimension dw and the Hausdorff dimension df have been determined on the length scales covered in the neutron scattering experiments
LB  - PUB:(DE-HGF)16
C6  - pmid:29865825
UR  - <Go to ISI:>//WOS:000433950200052
DO  - DOI:10.1063/1.5018717
UR  - https://juser.fz-juelich.de/record/847921
ER  -