Durability of Solid Oxide Electrolysis Cells for Syngas Production

Performance and durability of Ni-YSZ supported solid oxide electrolysis cells (SOECs) for co-electrolysis of H 2 O and CO 2 at high current density was investigated. The cells consist of a Ni-YSZ support, a Ni-YSZ electrode, a YSZ electrolyte, and an LSM-YSZ electrode. The durability was examined at 800°C and electrolysis current densities of −1 or −1.5 A/cm 2 with 60% reactant (H 2 O + CO 2 ) utilization. The cell voltage degradation showed a strong dependence on the electrolysis current density. Electrochemical characterization of the cells showed that the degradation was mainly related to the LSM-YSZ electrode when operated at −1 A/cm 2 , whereas at increased current density (−1.5 A/cm 2 ), both the Ni-YSZ and the LSM-YSZ electrode degraded. The initial degradation (0 - 200 h) is mostly due to increasing of polarization resistance, while the long term degradation is mainly caused by increasing of serial resistance.