A High-Capacity Lithium–Gas Battery Based on Sulfur Fluoride Conversion

Identification of novel redox reactions that combine the prospects of high potential and capacity can contribute new opportunities in the development of advanced batteries with significantly higher energy density than today’s state-of-the-art, while advancing current understanding of nonaqueous electrochemical transformations and reaction mechanisms. The immense research efforts directed in recent years toward metal–gas, and in particular lithium–oxygen (Li–O2) batteries, have highlighted the role that gas-to-solid conversion reactions can play in future energy technologies; however, efforts have mainly focused on tailoring the anode (alkali metal) in the metal–gas couple to achieve improved reversibility. Here, in a different approach, we introduce and characterize a new gas cathode reaction that capitalizes on the full change in the oxidation state (from +6 to −2) available in redox-active sulfur, based on the cathodic reduction of highly fluorinated sulfur hexafluoride (SF6) in a Li metal battery. In a...