报告题目：Zn batteries: Stable Anode and High Energy Cathodes
报告人：支春义（香港城市大学，教授）
报告时间：2023年12月29日 （星期五）下午14:00
报告地点：大学城校区B5栋副楼3楼会议室
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材料科学与工程学院
2023.12.27
Abstract
Our research focuses on a stable aqueous Zn-based battery with long cycling stability, decent energy density, and ultimate safety performance for large-scale energy storage. To achieve this purpose, we did systematic studies on the Zn metal anode, electrolytes, and new cathode development.
For the anode side, we developed a few strategies, including pH value manipulation, ion redistribution coating, gradient coating, etc to induce stable stripping and plating of Zn. Moreover, we also found that a Zn initially plated can be much more stable than the one initially stripped during the subsequent deposition. We further utilize this observation to develop a pre-deposited Zn for Zn batteries with improved stability.
For the electrolyte, we develop a reverse micelle electrolyte, with it, the Zn anode exhibits balanced merits including strong H2 coevolution suppression, prevention of dendritic and dead Zn, inhibition of corrosion, as well as relatively fast reaction kinetics. In a more extensive context, the new reverse micelle structure of electrolytes is expected to benefit other emerging battery chemistries, where a balance between fast ion transport and sufficient stabilization against side reactions is required.
For the cathode with high energy density, we studied the critical research concerns and further potential developments of chalcogen/halogen-based batteries, primarily focusing on the electrochemically active chalcogen/halogen sources, reaction modes, soluble products, and electrolyte adaptability.
For the cathode, we use iodine as the fixing agents working in highly concentrated electrolytes to successfully enable reversible Cl-based redox electrode. The interhalogen coordinating chemistry fixes Cl in a configuration of ICl3-. Furthermore, we simultaneously exploit two redox centers of Cl and I to realize a novel three-electrons transfer electrode, in which the Cl-I electrode can deliver remarkably high capacity up to 612.5 mAh gI-1 and energy density as 905 Wh kgI-1. The as-obtained energy density is 387% higher compared to the traditional one-electrons transfer of ZnǁI2 battery system and superior cycling stability with capacity retention as 95.7% after 2,000 cycles.
Biography of Invited Speaker
Chunyi ZHI obtained B.S. degree in Physics from Shandong University and Ph.D. in condensed matter physics from the Institute of Physics, Chinese Academy of Sciences. After two years of a postdoctoral fellow at the National Institute for Materials Science (NIMS) in Japan, he was promoted to ICYS researcher, researcher, and senior researcher (permanent position) at NIMS. Dr. Zhi is now a chair professor at MSE, City University of Hong Kong.
Dr. Zhi has extensive experience in flexible energy storage, aqueous electrolyte batteries, and zinc ion batteries. He has published over 500 papers with an h-index of 131 and citations of 59000. He has been granted more than 100 patents.
Dr. Zhi is a recipient of the Outstanding Research Award and President Award of CityU, NML Researcher award, and the Beijing Science and Technology Award (first class). He is a Clarivate Analytics Global highly cited researcher (2019-2023, Materials Science), RSC fellow, member of The Hong Kong Young Academy of Sciences and RGC Senior Research Fellow.