Fig. 5: Schematic summary of the operation of the SOFC in a single-chamber configuration as observed operando in the ETEM.
From: Operando analysis of a solid oxide fuel cell by environmental transmission electron microscopy
a At low O2-to-H2 ratios, the absence of O2 prevents its reduction at the cathode. b When introducing O2, the cell starts to deliver a voltage synonym of its operation until (c) the surface of the Ni grains oxidises. d When decreasing the O2-to-H2 ratio, the surface of the NiO scale starts to reduce into Ni islands, re-initiating the oxidation of the fuel at the anode, which results in a voltage increase. e The process stops at low O2-to-H2 ratios (as in a). YSZ stands for yttria-stabilised zirconia, LSM for lanthanum strontium manganite.
