Anti-Corrosive Electrolyte Designs for Lithium Metal Batteries

Electrolyte is a very critical component in lithium metal batteries (LMBs). It is recognized that the solvation structure near the Li ion plays a crucial role in determining the solid-electrolyte-interphase (SEI) properties and thus the reversibility of Li plating and stripping. The concepts of highly concentrated electrolyte (HCE) and locally highly concentrated electrolyte (LHCE) have received much attention these days because of their ability to induce inorganic-rich SEI that is beneficial in improving the cycle life. Nonetheless, most of fluorinated solvents used as diluents in LHCEs have low LUMO levels such that Li metal can easily corrode upon in contact with the electrolytes. I will introduce my group’s recent approach of adding an inert solvent in the electrolyte to serve as a kinetic barrier for fluorinated diluents in the so-called swollen SEI layer. The given approach can be expanded to a variety of electrolyte combinations with which both the cycle life and calendar life of LMBs can be improved simultaneously.