报告题目：Potential transition and instabilities in ceramic solid electrolytes

报告人：董岩皓 助理教授 清华大学

时   间：2023年4月13日（星期四）上午10:00

地   点：南楼三层会议室

邀请人：技术发展部 郑强 研究员

报告摘要：

Ceramic solid electrolytes are key components of many electrochemical devices such as solid oxide fuel/electrolysis cells (SOFC/SOEC), protonic ceramic fuel/electrolysis cells (PCFC/PCEC), and all-solid-state batteries. As their applications are pushed towards lower temperatures and extreme electrochemical conditions, the stability of ceramic solid electrolytes is challenged, and a better understanding of the degradation mechanisms is needed. Here we seek to understand the electrolyte degradation mechanisms from the perspectives of minor electronic charge carriers and the internal chemical potential distribution of a charge-neutral species such as O2 for SOFC/SOEC and Na/Li for all-solid-state batteries [Acta Mater. 199, 264-277, 2020; Chem. Mater. 34, 5749-5765, 2022]. The role of a p-n junction in the minor electronic channel shall be discussed. We further show that the intrinsic benefits of ceramic solid electrolytes can be hindered by non-ideal electrochemical interfaces, as is the case in PCFC/PCEC working at intermediate temperatures [Nature 604, 479-485, 2022]. The latter has a mechanical origin due to poor interfacial contacts and can be resolved via an acid etching process that enables reactive sintering at nanoscale. These new understandings and practices would help develop ceramic solid electrolytes further for current and emerging applications.

报告人简介：

Dr. Yanhao Dong is an assistant professor in the School of Materials Science and Engineering at Tsinghua University. He obtained his BS degree in materials science in 2012 from Tsinghua University, and his MS degree in materials science in 2014, his MS degree in applied mechanics in 2015, and his PhD degree in material science in 2017, all from University of Pennsylvania. His PhD dissertation focused on cation diffusion in zirconia ceramics, covering from experiments of sintering and grain growth to continuum-level solution of transport and growth theory to atomistic simulations of defect energetics and kinetics. He then spent five years at Massachusetts Institute of Technology as a postdoctoral researcher working on interdisciplinary materials design, processing, microstructure, and degradation mechanisms. He received Early Discovery Award, Edward C. Henry Award, Morgan Medal and Global Distinguished Doctoral Dissertation Award, and lifetime membership from the American Ceramic Society, Acta Student Award from Acta Materialia, and Sidney J. Stein Prize from University of Pennsylvania. His current research interest is on advanced ceramics for structural and energy applications.