Computational Study of New Proton Conducting Perovskites for Energy Applications

Latvian Council of Science Grant No. LZP-2020/2-0009

Principal Investigator: Dr. Yuri Mastrikov

Duration: 2020-2021

Proton-conducting materials play an increasingly important role in electro-chemical devices for energy production and accumulation-- Protonic Ceramic Fuel Cells (PCFC), Electrolysis Cells (PCEC) etc. LnScO3 (Ln-lanthanide) is a new class of advanced proton-conducting materials. Higher stability in reduced and carbon-containing atmosphere, unlike commonly used BaZrO3- and BaCeO3-based materials, makes them a very promising candidate for above mentioned applications. After Sr doping, La1-xSrxScO3-x/2 undergoes an extraordinary structural transformation: Instead of forming oxygen vacancies, like most perovskites, La1-xSrxScO3-x/2 accommodates a mesh-like structured defects. Extensive experimental studies suggest the presence in the structure of edge-sharing oxygen octahedra. Similar defect formation mechanism was discussed for lanthanum niobite with scheelite structure. Proposed project aims at an atomistic modelling of oxygen deficient La1-xSrxScO3-x/2. This study includes structural as well as energetic properties of edge-shared oxygen octahedra domains. These domains provide a great opportunity for completely new mechanisms of water, hydrogen and oxygen adsorption, dissociation, incorporation and migration. Our predictions based on the state-of-the-art computer modelling will be experimentally validated by collaborators from Max Planck Institute for solid state research, Stuttgart, Germany.