Presentation Title: Lithium/Sulfide All-Solid-State Batteries using Sulfide Electrolytes

Abstract: 

     Sulfide electrolytes are considered as one of the most promising solid electrolytes for all-solid-state lithium/sulfide batteries due to their high ionic conductivities and favorable interface compatibility with sulfur-based cathodes. Over the past decade, various sulfide electrolytes with room temperature ionic conductivity of 10^-3 ~ 10^-2 S/cm have been synthesized. Nevertheless, there are still some challenges for their commercial application in all-solid-state lithium batteries, including insufficient chemical/electrochemical stabilities and precise controllable solid electrolyte film thickness.

     In our group, we have demonstrated that the moisture stability can be improved by LiF-coating or fluorine doping. Based on the high ionic conductive sulfide electrolyte powder, thin film can be obtained by cold press solid electrolyte with surface modification, dry film method and wet coating approach. Due to similar chemical potential, a series of transition metal sulfides or sulfur-based materials are employed as cathode, and an intimate solid-solid contact can be acheived by in situ growth of sulfide electrolyte on the surface of active materials. Besides, adaptive interphase has been designed to dynamically fill the voids at lithium/solid electrolyte interface, enabling pressure-free all-solid-state lithium metal batteries.

Biography: 

      Xiayin Yao is a professor at Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences (NIMTE, CAS). He received his Ph.D from Institute of Solid State Physics and NIMTE, CAS in 2009. After that, he joined NIMTE and worked there until now. He worked as a research fellow or visiting scholar in Hanyang University, S. Korea (2012–2013), Nanyang Technological University, Singapore (2013–2014) and University of Maryland, College Park, USA, (2018–2019). So far, he has coauthored over 250 peer-reviewed journal papers, including Nature Sustainability, JACS, Adv Mater, etc., and applied more than 100 Chinese patents. His major interests include all-solid-state lithium/sodium batteries.