Hongqian (Sharon) Wang


Major: Materials Science and Engineering
Office: Cook 4049
Phone: (847) 491-7805
Email: hongqianwang2013@u.northwestern.edu

2013-Present Ph.D. Candidate, Materials Science and Engineering, Northwestern University
2009-2013 B.S., Chemistry/Materials Science, Purdue University

Research: Electrochemical Performance and Degradation of SOFC Electrodes

In recent years, mixed ionic-electronic conducting (MIEC) materials such as (La,Sr)(Co,Fe) O3-δ have been studied and developed as SOFC cathodes, due to their high activity for the oxygen reduction reaction at intermediate temperatures (600-800°C). However, in addition to particle coarsening/sintering, a number of MIEC materials containing Sr exhibit Sr surface segregation, which has been proposed to hinder the oxygen surface exchange process and become an important issue for the long-term stability of SOFCs utilizing MIEC cathodes.
My current research focuses on understanding the degradation mechanisms of porous MIEC cathodes in order to predict and improve their long-term stability. Life testing experiments at various elevated temperatures are carried out to accelerate any degradation. Morphological changes are analyzed using 3D FIB-SEM tomography technique. A novel technique utilizing chemical dissolution and ICP-OES measurement has been developed to quantify Sr surface segregation on the porous SOFC electrodes.