Nonvolatile and Nonflammable Sulfolane-Based Electrolyte Achieving Effective and Safe Operation of the Li-O₂ Battery in Open O₂ Environment.

Abstract

The Li-O₂ battery should operate effectively/safely in an open O₂ environment for practical applications, but not trapped in sealed/closed atmosphere. However, the typical use of volatile and flammable electrolyte restricts Li-O₂ battery to be able to be running in open O₂ environment. We report herein, for the first time, a highly electrochemical reversible Li-O₂ battery operated in an open O₂ environment, i.e., under the condition of keeping O₂ flowing continuously based on a nonvolatile and nonflammable sulfolane (TMS) solvent. The electrochemical irreversibility of Li₂O₂/O₂ conversion and incompatibility between Li metal anodes and electrolyte have been addressed via dissolving LiNO₃ in concentrated TMS electrolyte. The tuned electrolyte not only enables a stable solid electrolyte interphase (SEI) with conformal inorganic components (including LiF, LiN_<i>x</i>O_<i>y</i>, and Li₂O) that promotes a uniform Li electro-plating/stripping process but also results in a low charge overpotential, a stable discharge terminal plateau, and reversible O₂ generation of the Li-O₂ battery conducted in an open O₂ environment.