Solid Oxide Electrolysis Cells performance related to grain boundary crystallography.
Solid Oxide Electrolysis Cells (SOEC) are competitive systems to deliver low-cost, high-efficiency hydrogen production on an industrial scale. A typical SOEC consists of a porous cathode and anode, and commonly a dense electrolyte layer. The porosity enables the transport of fuel and electrolysis products in and out of the cell and increases the reactive surface. The surface crystallography of the particles in contact with pores and the grain boundaries between the particles building the porous structure varies with processing of the SOEC and influences their performance. Yet systematic studies linking electrical performance and degradation to the grain boundary crystallography are not available. This limits our ability to quantitatively guide material and component design and adjustment of grain boundary structure and crystallography through processing.
In this project, we will combine complementing characterization techniques available at Imperial College London and the Department of Materials at the University of Oxford to illuminate the interplay between grain boundary crystallography and the electrical performance of SOEC.
a) Schematic of partial SOEC, where H2O is dissociated to form H2 and O2. The porous structures or commonly displayed as rounded particles. Yet it is well known that different crystallographic facets develop and show different electrolyzing abilities, redrawn after (Ding et al 2020, Nat Com). b) Using EBSD and PED we can extract the grain boundary crystallography of pore-crystal interfaces as well as crystal-crystal interfaces. These interfaces change depending on processing conditions, but also during degradation, displayed in stereographic projections.
