Reversible solid oxide cell (rSOC) and solid oxide electrolysis (SOE) are gaining growing interest because they can convert both electricity into a chemical fuel and fuel back to electricity with high efficiency. This work summarizes for the first time the electrochemical performance characterization of Elcogen E350 stack both in fuel cell and electrolysis modes. Elcogen E350 stack is composed of 15 unit layers all having an 121 cm² active electrode area. The electrochemical characterization is conducted in temperature region 650 – 700 °C and with varying current densities, multiple steam-to-hydrogen ratios, reactant utilizations and air flow rates. Results indicate that the stack can be used not only as a fuel cell but also in electrolysis mode and it is capable to be operated up to 1 A/cm²current density already at 650 °C and can be operated also with high reactant utilization even in electrolysis mode.

Figure 1. (left) Elcogen E350 polarization at conditions: T[furnace] = 650°C, T[air,inlet] = T[fuel,inlet] = 640 °C, V[steam] = 21.1 Nl/min, V[H₂] = 2.24 Nl/min, V[air] = 67 Nl/min. (right) Elcogen E350 polarization at conditions: T[furnace] = 650°C, T[air,inlet] = T[fuel,inlet] = 640 °C, V[steam] = 7.76 Nl/min, V[H₂] = 7.76 Nl/min, V[air] = 33 Nl/min.