Christopher Crain, SLAC

Abstract

Oxide conducting Solid Oxide Electrolyzer Cells (O-SOECs) have shown great promise as high temperature electrolysis (HTE) materials which are necessary for large scale hydrogen generation. Currently, state of the art O-SOECs comprise of a porous nickel-yttrium-stabilized zirconia composite (Ni-YSZ) fuel electrode, a dense YSZ oxide-conducting solid electrolyte, a cation diffusion barrier (often Gd-doped CeO2), an air electrode, typically made of lanthanum strontium cobalt ferrite (LSCF), and related contacts/interconnects. Steam is split at the Ni-YSZ triple phase boundary, while the cell potential facilitates oxide diffusion through the cell allowing for separation of hydrogen and oxygen. While electrochemical measurements are commonly used to monitor cell perfomance, they are relatively insensitive to the onset of degradation which precedes cell failure. Advanced structural characterization is required in order to form a more sensitive and comprehensive understanding of degradation processes due to cell aging. Synchrotron X-rays are an ideal probe with the brilliance necessary to obtain structural and chemical information from O-SOECs across length and time-scales during aging processes. This presentation will highlight ongoing work performed on O-SOECs that utilizes X-ray scattering techniques intended to elucidate structural-related degradation of these layered materials. A new robot-automated high-throughput platform for accelerating X-ray scattering measurements and analysis of O-SOECs will be discussed.