Integration of Binary Active Sites: Co3 V2 O8 as Polysulfide Traps and Catalysts for Lithium-Sulfur Battery with Superior Cycling Stability

Linlin Zhang; Fang Wan; Hongmei Cao; Lili Liu; Yijing Wang; Zhiqiang Niu

doi:10.1002/smll.201907153

Integration of Binary Active Sites: Co₃ V₂ O₈ as Polysulfide Traps and Catalysts for Lithium-Sulfur Battery with Superior Cycling Stability

Small. 2020 May;16(18):e1907153. doi: 10.1002/smll.201907153. Epub 2020 Apr 13.

Authors

Linlin Zhang^{1

2}, Fang Wan¹, Hongmei Cao¹, Lili Liu³, Yijing Wang¹, Zhiqiang Niu¹

Affiliations

¹ Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Center, College of Chemistry, Nankai University, Tianjin, 300071, P. R. China.
² The Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, P. R. China.
³ Tianjin Key Laboratory for Photoelectric Materials and Devices, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin, 300384, China.

PMID: 32285595
DOI: 10.1002/smll.201907153

Abstract

Lithium-sulfur (Li-S) batteries as a promising energy storage candidate have attracted attention due to their high energy density (2600 Wh kg^-1 ). However, the serious shuttle effect caused by the dissolution of the lithium polysulfides (LiPS) in electrolyte significantly degrades their cycling life and rate performance. Herein, the "binary active sites" concept in a Li-S battery system via the design of a cobalt vanadium oxide (CVO) modified multifunctional separator is designed. In the case of CVO, active vanadium sites simultaneously anchor the LiPS through the chemical affinity and active cobalt sites can dominate a rapid kinetic conversion. Such a synergistic effect contributes to improving the utilization of sulfur in the electrochemical process for the enhanced electrochemical performance. As a result, the Li-S battery with the CVO modified separator possesses a high reversible capacity of 1585.5 mAh g^-1 at 0.1 C and superior cycling stability with 0.012% capacity decay cycle^-1 after 3000 cycles. More impressively, the assembled soft-packaged Li-S devices can exhibit the excellent stability under bending states. This binary active sites strategy provides a route to design the functional materials for modifying separators of Li-S batteries to improve the performance.

Keywords: binary active sites; energy storage; lithium-sulfur batteries; multifunctional separators.

Abstract

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