High-Performance Lithium-Oxygen Battery Electrolyte Derived from Optimum Combination of Solvent and Lithium Salt.

ABSTRACT: To fabricate a sustainable lithium-oxygen (Li-O₂) battery, it is crucial to identify an optimum electrolyte. Herein, it is found that tetramethylene sulfone (TMS) and lithium nitrate (LiNO₃) form the optimum electrolyte, which greatly reduces the overpotential at charge, exhibits superior oxygen efficiency, and allows stable cycling for 100 cycles. Linear sweep voltammetry (LSV) and differential electrochemical mass spectrometry (DEMS) analyses reveal that neat TMS is stable to oxidative decomposition and exhibit good compatibility with a lithium metal. But, when TMS is combined with typical lithium salts, its performance is far from satisfactory. However, the TMS electrolyte containing LiNO₃ exhibits a very low overpotential, which minimizes the side reactions and shows high oxygen efficiency. LSV-DEMS study confirms that the TMS-LiNO₃ electrolyte efficiently produces NO₂^-, which initiates a redox shuttle reaction. Interestingly, this NO₂^-/NO₂ redox reaction derived from the LiNO₃ salt is not very effective in solvents other than TMS. Compared with other common Li-O₂ solvents, TMS seems optimum solvent for the efficient use of LiNO₃ salt. Good compatibility with lithium metal, high dielectric constant, and low donicity of TMS are considered to be highly favorable to an efficient NO₂^-/NO₂ redox reaction, which results in a high-performance Li-O₂ battery.

SUBMITTER: Ahn SM 

PROVIDER: S-EPMC5644260 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature