Weining Wang
Advisor: Prof. Meilin Liu

will propose a doctoral thesis entitled,

Development of Novel Electrode and Electrolyte Materials for Proton-Conducting Solid Oxide Cells

On

Monday, November 30 at 2:30 p.m.
J. Erskine Love Room 210

Committee
            Prof. Meilin Liu – School of Materials Science and Engineering (advisor)
            Prof. Preet Singh – School of Materials Science and Engineering
            Prof. Hamid Garmestani – School of Materials Science and Engineering

            Prof. Faisal Alamgir – School of Materials Science and Engineering

            Prof. Nian Liu – School of Chemical and Biomolecular Engineering

Abstract

Proton-conducting solid oxide cells (P-SOCs) offer great potential for highly efficient electricity generation and fuel production. However, their widespread application is impeded by insufficient air-electrode activity and durability under practical operating conditions, particularly in H2O- and CO2-rich environments. This dissertation aims to address these challenges through the development of new electrolyte and air-electrode materials. rational design, synthesis, and mechanistic investigation of, and multi-doped proton-conducting electrolytes.

The first objective is to develop triple ionic-electronic conducting (TIEC) air electrode materials with high catalytic activity for oxygen reduction and evolution while maintaining adequate stability against high concentrations of steam and CO2. BaCoO3-δ (BCO)-based TIEC air electrodes will be optimized through B-site substitution with cations commonly used in proton-conducting electrolytes, such as Hf, Sn, Y, and Yb, to promote coupled electronic, oxygen-ion, and proton transport while improving structural stability under high-steam conditions. Electrochemical activity and durability will be evaluated in symmetrical cells and single cells. The oxygen reduction reaction (ORR) kinetic will be investigated using distribution of relaxation times (DRT) analysis and in situ Raman spectroscopy, while oxygen and proton transport will be characterized using electrical conductivity relaxation (ECR) measurements.

The second objective is to enhance chemical stability of electrolytes against H2O and CO2 while maintaining high proton conductivity. Multi-dopant strategies integrating donor, isovalent, and acceptor dopants will be explored to mitigate the conductivity-stability trade-off. The electrolyte will be characterized using electrochemical impedance spectroscopy (EIS), potentiometry, hydrogen-deuterium isotope exchange, thermogravimetric analysis (TGA), and steam/CO2 exposure tests to assess proton transport, hydration behavior, and chemical stability. Promising compositions will be evaluated for compatibility with Ni-based fuel electrodes and then incorporated into P-SOCs to assess cell performance and durability.