A Salt-Philic Solvent-Phobic (SP2) Interfacial Coating Design for Lithium Metal Electrodes

A key challenge to enable lithium (Li) metal batteries as next-generation energy storage devices is to stabilize the interface between Li metal and the electrolyte. A promising strategy is to promote the formation of a salt-derived solid electrolyte interphase (SEI), which has been found more robust and stable than a solvent-derived SEI. Here, we report a Salt-Philic Solvent-Phobic (SP2) polymer coating design concept for Li metal electrode that selectively transports salt over solvent and thus promotes salt-derived SEI formation. This SP2 coating approach resulted in enhanced cycling performance in several types of solvents, such as ether, carbonate, and fluorinated ether and achieved ~400 cycle life (2.5 mAh cm-2, 80% capacity retention) in 50 µm Li|NMC batteries.<br/>My talk will cover the materials design principles for SP2 polymers and characterizations on its unique salt-over-solvent transport property.