6月24日学术报告预告
TITLE: Degradation of Polymer Electrolyte Membrane in PEM Fuel Cells: Mechanistic Study and Mitigation
ABSTRACT: Durability is one of the barriers for the commercialization of polymer electrolyte membrane (PEM) fuel cell, which is a very promising technology for powering future zero-emission automobiles. Ionic conducting polymer membrane (ionomer) is a central element in a PEM fuel cell. Perfluorosulfonic acid (PFSA) polymer is the most widely used PEM membrane which serves the dual function of reactant separation and selective ionic conduction. The degradation and subsequent breach of electrolyte membrane leads to sudden premature failure of PEM fuel cells. This used to be the life-limiting failure mode of PEM fuel cell stack. Decades of research has revealed that the degradation of PFSA membrane involves coupled mechanical, physical, chemical, and electrochemical phenomenon. The speaker had conducted extensive single-factor study as well as coupled-effect study on PEM membrane degradation mechanisms using experiments, modeling, and advanced characterization techniques. A very interesting phenomenon observed during membrane degradation process is damage localization, where a small region in the electrolyte membrane becomes highly degraded while other regions of membrane remain intact. Latest supporting evidence was collected in the speaker’s group using in situ local Raman spectroscopy measurement. Potential mechanisms for this process will be discussed. The localization process is believed to be strongly coupled with the electrode degradation process. Based on the improved understanding of the membrane degradation mechanisms, a number of mitigation methods have been discovered, some of them are found highly effective in reducing membrane degradation rate. This has resulted in the shift of life-limiting factor of PEM fuel cells to electro-catalyst degradation. Overall, the durability of PEM fuel cells have improved significantly after decades of R&D efforts, approaching the life time target for commercial applications.
BIO: Xinyu Huang received a PhD degree in Engineering Science and Mechanics from Virginia Tech in 2001 under the direction of Prof. Ken Reifsnider. In 2002, he joined the Connecticut Global Fuel Cell Center, where he spent 6 years working on the design, durability and reliably of fuel cell materials and device, collaborating with leading industrial fuel cell developers (Fuel Cell Energy and UTC Power) in Connecticut. In 2008, he joined the University of Central Florida as a tenure-track Assistant Professor at the Department of Mechanical Materials and Aerospace Engineering with a joint appointment at the Advanced Energy Research Division of the Florida Solar Energy Center. In 2010, he took an offer to join the Mechanical Engineering Department and the SOFC program at Univ. of South Carolina (USC). There, he started to explore processing-structure-property relationship of fuel cell electrodes. Currently, he is sponsored by National Science Foundation, NASA, and Mystic Technology Partners on fabricating fuel cell electrodes for various applications: cathode of solid oxide fuel cells, electrode for PEM fuel cells (for automotive applications and space applications), and electrodes for phosphoric acid fuel cells, etc.
欢 迎 参 加
