Highly Active Nanostructured Electrodes for High Temperature, Degradation-Resistant Solid Oxide Reversible Cells

University Of Utah, Salt Lake City UT

Investigators

Abstract

CBET - 1604008 PI: Virkar, Anil V. The proposed work deals with the stabilization of oxygen (i.e. air) electrodes for high-temperature solid oxide electrolysis cells (SOECs), which are used primarily for converting water to hydrogen. Such devices could be a key component of a sustainable energy and chemicals future based on wind or solar energy. The project will focus on synthesis of nanoparticle materials that have potential to improve the efficiency and stability of SOECs. The proposed work addresses a fundamental stability problem in solid oxide electrochemical cells that is shared among a number of devices including solid oxide fuels cells operating in the reversible mode and certain batteries. Thus, findings that will come out of the study can potentially benefit energy storage and conversion devices more broadly than SOECs alone. SOECs typically operate at high electrode overpotentials, which in turn, can result in build up of effective oxygen pressure at the electrode-electrolyte interface, in some cases to the point of bubble formation. The oxygen build-up can lead to internal cracking and electrode delamination. Thi project is based on the proposition that nanostructured electrodes consisting of ionically-conducting particles electrode and electrolyte materials can substantially lower polarization resistance, lower oxygen pressure (and the risk of bubble formation), and thereby suppress degradation. To this end, nanostructured perovskite oxygen electrodes in the range of 10-50 nm will be deposited on electrolyte discs and fuel electrode supported cells by a variety of techniques, and then characterized for polarization resistance using electrochemical impedance spectroscopy. The measured polarization resistance will be used in combination with microstructural analysis and calculations to predict degradation behavior that will be compared with experimental studies.