Boosting polysulfides immobilization and conversion through CoS2 catalytic sites loaded carbon fiber for robust lithium sulfur batteries

Yan Song; Jia Wang; Xiuyuan Li; Chenxu Zhao; Jinrong Huo; Chaozheng He

doi:10.1016/j.jcis.2021.10.015

Boosting polysulfides immobilization and conversion through CoS₂ catalytic sites loaded carbon fiber for robust lithium sulfur batteries

J Colloid Interface Sci. 2022 Feb 15;608(Pt 1):963-972. doi: 10.1016/j.jcis.2021.10.015. Epub 2021 Oct 12.

Authors

Yan Song¹, Jia Wang¹, Xiuyuan Li¹, Chenxu Zhao¹, Jinrong Huo², Chaozheng He³

Affiliations

¹ Institute of Environmental and Energy Catalysis, School of Materials Science and Chemical Engineering, Xi'an Technological University, Xi'an 710021, China; Shaanxi Key Laboratory of Optoelectronic Functional Materials and Devices, School of Materials Science and Chemical Engineering, Xi'an Technological University, Xi'an 710021, China.
² School of Sciences, Xi'an Technological University, Xi'an 710021, China.
³ Institute of Environmental and Energy Catalysis, School of Materials Science and Chemical Engineering, Xi'an Technological University, Xi'an 710021, China; Shaanxi Key Laboratory of Optoelectronic Functional Materials and Devices, School of Materials Science and Chemical Engineering, Xi'an Technological University, Xi'an 710021, China. Electronic address: hecz2019@xatu.edu.cn.

PMID: 34785471
DOI: 10.1016/j.jcis.2021.10.015

Abstract

The practical applications of lithium sulfur battery is impeded by the lithium polysulfide shuttling and sluggish redox kinetics. To address the issues, herein, a multifunctional host is developed by the combination of nitrogen, phosphorus co-doped carbon fiber (NPCF) and CoS₂ towards boost the soluble polysulfides adsorption and transformation. Benefiting from the NPCF originated from biomass cattail fibers, a high conductive network is provided, and shuttle effect is reduced due to the strong chemical interaction between abundant heteroatom polar sites and lithium polysulfides. Moreover, the electrocatalytic CoS₂ on the carbon skeleton facilitate lithium polysulfides conversion and lithium sulfide deposition based on the density functional theory calculations and experiments. The efficient lithium polysulfides entrapment and subsequent electrocatalytic conversion improve dynamic stability during cycling, especially for rate capability. With these advantageous features, the electrode with NPCF/CoS₂ host can deliver a good rate capability (903 and 782 mAh g^-1 at 1C and 2C, respectively) and stable cycling performance with an ultra-low capacity decay of 0.014% per cycle at 1C. Notably, the cell can achieve a high areal capacity of 4.96 mA h cm^-2 under an elevated sulfur loading of 5.0 mg cm^-2. Overall, the improvement on the electrochemical performance ascertains the validity of the design strategy based on synergy engineering, which is a highly suitable approach for energy storage and conversion application.

Keywords: Biomass carbon fiber; Cobalt sulfide; Lithium sulfur battery; N, P co-doping; Polysulfides.