Lithium-ion batteries are promising energy storage systems for electric vehicles and smart-grid storage systems. However, the needs for new batteries with higher energy than that of the current lithium-ion batteries are increasing. Among many battery systems, lithium-sulfur (Li-S) batteries are one of the most attractive candidates for next-generation high-energy density batteries due to high theoretical capacity of sulfur of 1672 mAh/g.¹ However, commercialization of Li-S batteries has been hindered by  the issues such as the insulating nature of sulfur and lithium sulfide (Li₂S) and polysulfide shuttle electrode-electrolyte interfacial instability. In order to achieve high performance Li-S batteries, much research efforts have devoted to solve those problems by preparing sulfur-based composite with porous carbon, and optimizing electrolyte composition and concentration and functional binder.^2,3 However, report of the development of new sulfur material, and its electrochemical behavior and reaction mechanism, and correlation to the cycling performance of Li-S batteries is limited. Herein, we report on the improvement of electrochemical performance of an advanced sulfur cathode material by optimizing the cathode composition and electrolyte concentration. Correlation between the cycling performance and the changes in surface property and particle morphology of sulfur cathode material with cycling, which is obtained through ex situ X-ray photoelectron spectroscopy and scanning electron microscopy, would be presented in the meeting.

Acknowledgements

This work was supported under the framework of international cooperation program managed by National Research Foundation of Korea (2015K2A5A3000068) and German Academic Exchange Service (57141898).

 

References

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3. S. Urbonaite, and P. Novák, J. Power Sources, 249, 497 (2014).