CoS₂@SC modified separator for high-performance lithium-sulfur batteries: suppression of polysulfide shuttling

ABSTRACT

Due to their high energy density and cost-effective electrode materials, lithium sulfur batteries (LSBs) have been considered as one promising candidate of energy devices. However, the practical application is impeded by the shuttle effect of lithium polysulfides and slow redox kinetics of electrode. Here, we report a successful synthesis of CoS₂@SC composite material via in-situ growth and sulfuration pyrolysis method and prepared CoS₂@SC modified separator. The carbon matrix derived from sucrose carbonization with a porous structure promotes the uniform distribution of active adsorption sites. According to Lewis acid–base interaction, CoS₂@SC separator exhibits strong chemisorption of lithium polysulfides, reducing the loss of active material during cycling. Furthermore, the enhanced wettability of the CoS₂@SC separator with the electrolyte accelerates the ion transfer, improving the reaction kinetics. Compared with the blank separator, the cell with CoS₂@SC separator has an initial specific capacity of 1135.5 mAh g⁻¹ and notably, the capacity decay rate of the modified battery is only 0.052% per cycle after 800 long cycles at 0.5 C. This unique attribute ensures enhanced stability and durability of the battery system. Consequently, LSBs with the CoS₂@SC separator exhibit an improved electrochemical performance.

KEYWORDS:

• Lithium sulfur batteries
• modified separator
• shuttle effect
• chemical adsorption
• metal sulfide

Acknowledgements

This work is financially supported by the National Natural Science Foundation of China, China (No. 21676148), and the Fundamental Research Funds for the Central Universities, China (No. 30918012202)

Disclosure statement

Wenju Wang reports financial support was provided by National Natural Science Foundation ofl China. Wenju Wang reports financial support was provided by Fundamental Research Funds for the Central Universities.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/15567036.2023.2259836.

Additional information

Funding

This work was supported by the Fundamental Research Funds for the Central Universities [30918012202]; National Natural Science Foundation of China [21676148].

Notes on contributors

Yongan Cao

Yongan Cao is the student of Nanjing University of Science and Technology.

Jiyuan You

Jiyuan You is the student of Nanjing University of Science and Technology.

Xuefei Liu

Xuefei Liu is the staff of the Fourth Construction Co, LTD of China Construction Eighth Engineering Division.

Xiaoqian Hao

Xiaoqian Hao is the student of Nanjing University of Science and Technology.

Qiao Wu

Qiao Wu is the student of Nanjing University of Science and Technology.

Bo Zhang

Bo Zhang is the student of Nanjing University of Science and Technology.

Zhiming Xu

Zhiming Xu is the student of Nanjing University of Science and Technology.

Liwei Deng

Liwei Deng is the student of Nanjing University of Science and Technology.

Wenju Wang

Wenju Wang is the teacher of Nanjing University of Science and Technology.

Yuqian Li

Yuqian Li is the teacher of Nanjing University of Science and Technology.