Kyung Yoon Chung

Abstract:

Sulfide based solid electrolytes are attracting attention because they have better electrochemical performances compared to other types of solid electrolytes. In addition, they have higher formability enabling favorable interfaces between the active material and solid electrolyte. Even though the sulfide based electrolyte shows better electrochemical characteristics among the various solid electrolytes, it poses some problems that have to be resolved such as poor compatibility of sulfide SEs against oxide-based cathode active materials and its instability against air and moisture.
This study presents the findings of a comparative analysis on the stability of two different sulfide solid electrolytes (SEs) which are glass-ceramic Li7P3S11 and crystalline Li6P5SCl. We synthesized both SEs using the same mechanical milling method in order to compare them under identical conditions. Then, the composite cathodes were prepared by simply mixing the SEs with the active materials and additives. We tried to observe any side reactions that occur during the charging and discharging process. Additionally, electrochemical characterization of the composite cathode were conducted using each SEs. Also, it is aimed to continuously monitor the degradation mechanism of the composite cathodes during the charging and discharging process, as well as evaluate their thermal stability under high-temperature conditions, utilizing X-ray based analytical techniques. The details will be discussed at the meeting.