Objective
To design optimal electrolyte solution to realize long-term stable lithium metal anode
- Theoretical specific capacity of lithium metal is apploximately 10 times higher than that of graphite used in conventional LIB
- Application of lithium metal instead of graphite enhances energy density
Challenge
Performance degradation due to dendritic lithium growth
Effect of salt concentration of electrolyte solution
Effect of salt concentration of electrolyte solution composed of LiFSI (lithium bis (fluorosulfonyl) imide) as a solute and SL (sulfolane) as a solvent on performance
SEM images of lithium surface deposited on copper foils
Increasing LiFSI concentration of electrolyte solution (LiFSI/SL) deposits round-shaped lithium and suppresses needle-like lithium
Coulombic efficiency of lithium stripping and plating on copper foil
With increasing LiFSI concentration of electrolyte solution (LiFSI/SL), Coulombic efficiency and cycle performance enhance
stripping and plating condition : 1 mA/ cm2, 0.5 mAh/ cm2
XPS analysis of lithium surface after stripping and plating on copper foil
- XPS analysis of lithium metal surface indicated that increasing LiFSI concentration of electrolyte solution forms a higher amount of LiF
- LiF would suppress dendritic lithium metal growth and contribute to stable lithium stripping and plating due to its high interfacial energy and wide electrochemical stability window
