Anode degradation is one of the main factors that limit the lifetime
of solid oxide cells (SOCs), and thus complicate their commercial
application. For nickel/yttria-stabilized-zirconia (Ni/YSZ) anodes,
one possible counter measure is re-activation through reverse
current treatment (RCT). This method has been described for
single cells by other researchers. In order to investigate the
applicability of RCT in SOC systems, we used this treatment on
anode supported short stacks. Two stacks that had been exposed to
different degradation phenomena were investigated. The first stack,
suffering from partial re-oxidation and a cracked cell, already
showed temporary performance improvement after electrolysis
operation under mild conditions. The second stack had degraded
over a thermal cycle, and different from the first one showed less
re-activation. RCT under dry conditions was found to cause severe
degradation. Furthermore, we found that, in agreement with
literature, YSZ becomes electronically conductive during the RCT,
meaning that electrolysis power during RCT is not limited by the
amount of available steam. We discuss the issues of this behavior
for SOC systems and possible solutions.
«
Anode degradation is one of the main factors that limit the lifetime
of solid oxide cells (SOCs), and thus complicate their commercial
application. For nickel/yttria-stabilized-zirconia (Ni/YSZ) anodes,
one possible counter measure is re-activation through reverse
current treatment (RCT). This method has been described for
single cells by other researchers. In order to investigate the
applicability of RCT in SOC systems, we used this treatment on
anode supported short stacks. Two stacks t...
»