Anion-doped polypyrrole three-dimensional framework enables adsorption and conversion in lithium-sulfur batteries

Guowei Yu; Chen-Yang Wang; Wenda Dong; Ya-Wen Tian; Zhaoyun Wang; Jingyi Lu; Pu Hu; Yong Liu; Min Yan; Yu Li; Zhitian Liu

doi:10.1016/j.jcis.2023.10.033

Anion-doped polypyrrole three-dimensional framework enables adsorption and conversion in lithium-sulfur batteries

J Colloid Interface Sci. 2024 Jan 15;654(Pt A):201-211. doi: 10.1016/j.jcis.2023.10.033. Epub 2023 Oct 10.

Authors

Guowei Yu¹, Chen-Yang Wang¹, Wenda Dong², Ya-Wen Tian², Zhaoyun Wang¹, Jingyi Lu¹, Pu Hu¹, Yong Liu², Min Yan³, Yu Li⁴, Zhitian Liu⁵

Affiliations

¹ Hubei Key Laboratory of Plasma Chemistry and Advanced Materials, Hubei Engineering Technology Research Center of Optoelectronic and New Energy Materials, School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan 430205, PR China.
² State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, PR China.
³ Hubei Key Laboratory of Plasma Chemistry and Advanced Materials, Hubei Engineering Technology Research Center of Optoelectronic and New Energy Materials, School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan 430205, PR China. Electronic address: yanmin@wit.edu.cn.
⁴ State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, PR China. Electronic address: yu.li@whut.edu.cn.
⁵ Hubei Key Laboratory of Plasma Chemistry and Advanced Materials, Hubei Engineering Technology Research Center of Optoelectronic and New Energy Materials, School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan 430205, PR China. Electronic address: able.ztliu@wit.edu.cn.

PMID: 37839237
DOI: 10.1016/j.jcis.2023.10.033

Abstract

Inhibiting the shuttle effect and propelling polysulfide conversion by introducing a suitable sulfur container has been proven as a promising strategy to enhance the cycle life of lithium-sulfur (Li-S) batteries. Here, a unique three-dimensional (3D) inter-connected framework assembled with SO₄^2--doped polypyrrole (PPy-SO₄) nanowires is proposed. The doping SO₄^2- anion in a polymer skeleton could confine lithium polysulfides (LiPSs) by polar-polar interaction to inhibit the shuttle effect and enhance the conductivity of PPy to accelerate polysulfide conversion. Moreover, the electrostatic coupling between SO₄^2- anion and Li⁺, as well as between -N⁺- and S_n^2-, at polypyrrole /electrolyte interface can effectively regulate the redox kinetics of polysulfide. Besides, the inter-connected framework creates a large contact surface for sulfur and high-flux paths for electron transport. Consequently, the Li-S batteries assembled with PPy-SO₄/S cathode exhibit a stable capacity of 501 mAh g^-1 after 350 cycles at 1C, showing a low decay rate of 0.09% per cycle. Notably, the efficiency of the anion doping strategy is further verified in the pouch cell, realizing a capacity of 480 mAh g^-1 after 250 cycles. This work illustrates that anion doping with rational structural design is a feasible solution to boost the electrochemical performance of Li-S batteries.

Keywords: 3D inter-connected framework; Anion-doped PPy; Conversion reaction kinetics; Lithium-sulfur batteries; Strong adsorption.