Electrolyte Comparison for Li-Metal Anodes with Cryo-Laser PFIB

Abstract

Insights into the interfacial reactions between lithium metal and volatile electrolytes provide the understanding needed to engineer lithium-metal batteries for high-energy density rechargeable energy storage. The integration of lithium-metal anodes into a rechargeable battery will provide significant gains in storage capacity and energy density over graphite electrodes used in lithium-ion batteries (LIB), but the uncontrolled interfacial reactions between lithium metal and common LIB electrolytes cause steady losses in performance due to uncontrolled solid electrolyte interphase (SEI) formation and Li-metal consumption. The SEI forms when electron transfer occurs at the surface of the Li-metal electrode, causing breakdown of the electrolyte into lithium containing species. Ideally these reactions create a passivating layer on the Li metal to prevent further reaction (to conserve the Li inventory) and to serve as a Li-ion conductor. Self discharge is caused by an insufficiently passivating SEI to prevent the Li metal oxidation by the electrolyte. To produce a commercial grade Li-metal anode for rechargeable energy storage, a high performance SEI is required, with properties defined by the electrolyte and current density for Li metal plating and stripping.