Sulfur-Rich Molybdenum Sulfide as an Anode Coating to Improve Performance of Lithium Metal Batteries

Abstract

In lithium metal batteries (LMBs), the reaction between metallic Li and organic electrolytes consumes both Li and electrolyte, while the inhomogeneity of the resulting solid-electrolyte interphase (SEI) contributes to inhomogeneous Li deposition. An artificial SEI, made by coating the Li surface with an electronically insulating material, can mitigate problems caused by uncontrolled SEI formation by 1) decreasing reduction of the electrolyte on the surface, and 2) increasing the uniformity of the Li+ flux to the electrode surface, thereby mitigating dendrite growth. In this work, we present a technique for coating the surface of LMB electrodes with sulfur-rich molybdenum sulfide. This coating acts as an artificial SEI, which improves the coulombic efficiency and cycling stability of the LMBs by improving the reaction kinetics and decreasing the surface area of the exposed Li.