High-efficiency and high-power rechargeable lithium\u2013sulfur dioxide batteries exploiting conventional carbonate-based electrolytes

Hyeokjun Park,Hyungjun Kim,Sehwan Moon,Won Mo Seong,Hee-Dae Lim,Youngmin Ko,Kisuk Kang,Hyung-Kyu Lim,Youngjoon Bae,Byungju Lee

doi:10.1038/ncomms14989

Abstract

Shedding new light on conventional batteries sometimes inspires a chemistry adoptable for rechargeable batteries. Recently, the primary lithium-sulfur dioxide battery, which offers a high energy density and long shelf-life, is successfully renewed as a promising rechargeable system exhibiting small polarization and good reversibility. Here, we demonstrate for the first time that reversible operation of the lithium-sulfur dioxide battery is also possible by exploiting conventional carbonate-based electrolytes. Theoretical and experimental studies reveal that the sulfur dioxide electrochemistry is highly stable in carbonate-based electrolytes, enabling the reversible formation of lithium dithionite. The use of the carbonate-based electrolyte leads to a remarkable enhancement of power and reversibility; furthermore, the optimized lithium-sulfur dioxide battery with catalysts achieves outstanding cycle stability for over 450 cycles with 0.2 V polarization. This study highlights the potential promise of lithium-sulfur dioxide chemistry along with the viability of conventional carbonate-based electrolytes in metal-gas rechargeable systems.

Highlights

Shedding new light on conventional batteries sometimes inspires a chemistry adoptable for rechargeable batteries
Under an analogous cell configuration adopted from lithium-oxygen batteries, it has been demonstrated that a reversible electrochemical reaction between Li and SO2 is possible with the formation and decomposition of lithium dithionite (Li2S2O4)
A slightly different energy trajectory of the electron transfer was observed in the two electrolyte systems, where the SO2À in the ethylene carbonate (EC)/dimethyl carbonate (DMC) is more stable by 0.30 eV than that in the TEGDME

Summary

Introduction

Shedding new light on conventional batteries sometimes inspires a chemistry adoptable for rechargeable batteries. The primary lithium-sulfur dioxide battery, which offers a high energy density and long shelf-life, is successfully renewed as a promising rechargeable system exhibiting small polarization and good reversibility. This study highlights the potential promise of lithium-sulfur dioxide chemistry along with the viability of conventional carbonate-based electrolytes in metal-gas rechargeable systems. The critical dependency on the electrolyte in the metal-gas system compared with conventional lithium/sodium ion batteries is most likely due to the generation of gas radicals, which are an important intermediate for the discharge reaction. The organic carbonate was highly vulnerable to chemical attacks by the oxygen radicals generated during the discharge process[14,15,26,28] This finding led to the overall perception that carbonate-based electrolytes cannot be considered for metal-air batteries. This report is the first to demonstrate that conventional carbonate-based electrolytes can be successfully applied in rechargeable metal-gas systems, opening up a new avenue towards high-efficiency rechargeable metal-gas batteries

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Results

Conclusion