TY - JOUR
T1 - Investigation of a Spinel-forming Cu-Mn Foam as an Oxygen Electrode Contact Material in a Solid Oxide Cell Single Repeating Unit
AU - Zielke, Philipp
AU - Wulff, Anders Christian
AU - Sun, Xiufu
AU - Jensen, Søren Højgaard
AU - Kiebach, Wolff-Ragnar
AU - Frandsen, Henrik Lund
AU - Norby, Poul
AU - Hagen, Anke
PY - 2017
Y1 - 2017
N2 - A critical issue in state-of-the-art solid oxide cell stacks is the
contacting of the oxygen electrode. The commonly used ceramic contact
layers are applied in a green state and cannot be sintered properly, due
to compliance limitations arising from other stack components like
sealing glasses and steels. The consequence is a low layer and interface
strength. A metallic copper manganese foam, which is oxidized under
operation conditions into a conductive Cu1+xMn2–xO4
spinel, is presented in this work as a viable contact solution. The
foam has been electrochemically tested in a single repeating unit setup
for 350 hours of constant operation, followed by dynamic conditions with
thermal cycles. After operation, a micro structural analysis using
scanning electron microscopy, energy dispersive X-ray spectroscopy and
X-ray diffraction was carried out. It was confirmed that after
oxidation/operation the manganese solely formed a CuMn-spinel phase,
mixed with a CuO phase. A separate Mn-oxide phase was not found. The
conductivity and contacting of the foam was sufficient for > 350 h of
SOFC operation. With an initial serial resistance comparable to single
cell tests using gold foil as contact material and moderate degradation
rates, the CuMn foam presented itself as an interesting cathode contact
solution.
AB - A critical issue in state-of-the-art solid oxide cell stacks is the
contacting of the oxygen electrode. The commonly used ceramic contact
layers are applied in a green state and cannot be sintered properly, due
to compliance limitations arising from other stack components like
sealing glasses and steels. The consequence is a low layer and interface
strength. A metallic copper manganese foam, which is oxidized under
operation conditions into a conductive Cu1+xMn2–xO4
spinel, is presented in this work as a viable contact solution. The
foam has been electrochemically tested in a single repeating unit setup
for 350 hours of constant operation, followed by dynamic conditions with
thermal cycles. After operation, a micro structural analysis using
scanning electron microscopy, energy dispersive X-ray spectroscopy and
X-ray diffraction was carried out. It was confirmed that after
oxidation/operation the manganese solely formed a CuMn-spinel phase,
mixed with a CuO phase. A separate Mn-oxide phase was not found. The
conductivity and contacting of the foam was sufficient for > 350 h of
SOFC operation. With an initial serial resistance comparable to single
cell tests using gold foil as contact material and moderate degradation
rates, the CuMn foam presented itself as an interesting cathode contact
solution.
U2 - 10.1002/fuce.201700005
DO - 10.1002/fuce.201700005
M3 - Journal article
SN - 1615-6846
VL - 17
SP - 730
EP - 734
JO - Fuel Cells
JF - Fuel Cells
IS - 5
ER -