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

The Li-O-2 battery should operate effectively/safely in an open O-2 environment for practical applications, but not trapped in sealed/closed atmosphere. However, the typical use of volatile and flammable electrolyte restricts Li-O-2 battery to be able to be running in open O-2 environment. We report herein, for the first time, a highly electrochemical reversible Li-O-2 battery operated in an open O-2 environment, i.e., under the condition of keeping O-2 flowing continuously based on a nonvolatile and nonflammable sulfolane (TMS) solvent. The electrochemical irreversibility of Li2O2/O-2 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, LiNxOy, 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 O-2 generation of the Li-O-2 battery conducted in an open O-2 environment.

Automated summary

This paper reports for the first time a highly electrochemical reversible Li-O-2 battery operated in an open O-2 environment. By using a nonvolatile and nonflammable solvent, the limitation of electrolyte for open O-2 environment is addressed. The stable solid electrolyte interface and reversible O-2 generation were achieved through the tuning of electrolyte composition.