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.

Experimental And Theoretical Characteristic Of Single Atom Co-N-C Catalyst For Li-O2 Batteries

“…Then, the production rate of O 2 was decreased gradually, it corresponded to the consumption of Li 2-x O 2 . [54][55][56] When the charge voltage reached 4.1 V, the O 2 evolution rate increased again owning to the decomposition of Li 2 O 2 at a higher voltage. The calculation data also confirmed this result.…”

Electrolytes for Rechargeable Lithium–Air Batteries

“…LiNO 3 is also beneficial for the formation of a stable SEI on the surface of lithium metal . When combined with a suitable solvent such as tetramethylene sulfone, the LiNO 3 ‐based electrolyte produced fewer side reactions than electrolytes based on other Li salts, because of the low overpotential originating from the NO 2 − /NO 2 redox reaction …”

Transition Metal Hollow Nanocages as Promising Cathodes for the Long-Term Cyclability of Li–O2 Batteries

“…This, in turn, prevents the formation of lithium carbonate that block the surface of the electrodes. Further, it has been confirmed by Ahn et al that the TEGDME is expected to undergo decomposition only above a voltage of 4.7 V. Considering the issues of electrolyte decomposition, a maximum voltage of 4.5 V was applied in this work [ 29 , 30 ]. It is observed from the CV curve in Figure 4 a that in the presence of oxygen, the ORR onset potential of the MOHNs/KB cathode is at 2.8 V vs. Li/Li + .…”