The effect of the solid electrolyte interphase (SEI) on a Li anode on the charge-discharge cycling performance in 1 M LiTFSI/dimethylsulfoxide electrolyte solution is examined by using charge-discharge cycling. The chemical structure of the surface and interior of the SEI strongly affects the cycling performance of the anode. The observed coulombic efficiency is low (<45%) when organic compounds such as lithium alkyl carbonates and polycarbonate form predominantly on the surface and interior. However, when inorganic compounds such as Li<inf>2</inf>CO<inf>3</inf>, Li<inf>2</inf>O, and LiF form instead, the coulombic efficiency increases to >85%. This enhanced efficiency remains constant regardless of the O<inf>2</inf> content and despite <1000 ppm concentration of the contaminant H<inf>2</inf>O in the electrolyte. Thus, the lithium surface should be protected by inorganic compounds prior to cycling to prevent it from undergoing side reactions with the electrolyte during cycling in the electrolyte.
ASJC Scopus subject areas
- Electrical and Electronic Engineering
- Energy Engineering and Power Technology
- Renewable Energy, Sustainability and the Environment
- Physical and Theoretical Chemistry