Search

The OxEon team led the development of solid oxide electrolysis cell(SOEC) stacks to convert atmospheric CO2 to pure O2 for the Mars Perseverance Rover mission. The cathode material set was not redox tolerant, therefore a recycle loop was implemented to include reducing CO gas in the stack feed. Since then, OxEon has investigated a combination of materials and engineering solutions to improve redox tolerance of the cathode materials so that 100% dryCO2 (or steam without H2) could be fed directly into a stack without harm. The developed set of cathode materials exhibit remarkable robustness through extreme redox cycling and thermal cycling, as well as higher coking tolerance from preliminary testing. This enables simpler operation (no recycle) and prevents damage from unintended system changes, providing a new solution to operational challenges in SOEC systems. Steam redox tolerance was independently verified from collaboration with Pacific Northwest National Laboratory (PNNL).

In this work, strontium-free copper-doped nickelates, La2Ni1-xCuxO4 (x=0.1-0.3), were synthesized using solid state synthesis method and tested as potential oxygen electrodes in solid oxide electrolysis cells (SOEC). Similar to the parent compound, the Ruddlesden-Popper (RP) La2NiO4 oxide, the Cu-doped compositions were confirmed to crystallize with tetragonal crystal structure with I4/mmm space group. The electrochemical performance of La2Ni1-xCuxO4 electrodes was studied using Ni-YSZ electrode-supported button cells in SOEC mode and compared to the state-of-the-art (La0.6Sr0.4)0.95Co0.0.8O3-δ (LSCF)-doped ceria composite electrodes. Electrochemical tests were conducted at 750oC with the Ni-YSZ hydrogen electrode exposed to 50% steam in hydrogen. The polarization resistance of SOEC with the La2Ni0.8Cu0.2O4 (LNCuO-20) electrode was lower than that with LSCF. LNCuO-20 showed stable current density output over 800 hours tested, while cell with LSCF showed more degradation.

not Available.