All-in-one Janus covalent organic frameworks separator as fast Li nucleator and polysulfides catalyzer in lithium-sulfur batteries

Hanyan Wu; Ming Jiang; Xuejie Gao; Xinyang Chen; Chen Cheng; Shuiping Cai; Wenfeng Ren; Xiaofei Yang; Runcang Sun

doi:10.1016/j.jcis.2024.02.038

All-in-one Janus covalent organic frameworks separator as fast Li nucleator and polysulfides catalyzer in lithium-sulfur batteries

J Colloid Interface Sci. 2024 May 15:662:138-148. doi: 10.1016/j.jcis.2024.02.038. Epub 2024 Feb 7.

Authors

Hanyan Wu¹, Ming Jiang², Xuejie Gao³, Xinyang Chen¹, Chen Cheng¹, Shuiping Cai¹, Wenfeng Ren¹, Xiaofei Yang⁴, Runcang Sun⁵

Affiliations

¹ Center for Lignocellulosic Chemistry and Biomaterials, College of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian 116034, China.
² Institute of Physical Science and Information Technology, Anhui University, Hefei 230601, China.
³ Center for Lignocellulosic Chemistry and Biomaterials, College of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian 116034, China. Electronic address: gaoxuejie1107@163.com.
⁴ Division of Energy Storage, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China. Electronic address: yangxf@dicp.ac.cn.
⁵ Center for Lignocellulosic Chemistry and Biomaterials, College of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian 116034, China. Electronic address: rcsun3@dlpu.edu.cn.

PMID: 38340513
DOI: 10.1016/j.jcis.2024.02.038

Abstract

The shuttle effect, sluggish conversion kinetics, and uncontrollable lithium dendrites seriously hinder the practical application of lithium-sulfur (Li-S) batteries. Among many modified materials, covalent organic frameworks (COFs) stand out for their excellent ability to inhibit the shuttle effect, while their role in promoting lithium nucleation and catalyzing the conversion of sulfur species has been largely ignored. In this study, an integrated COF separator (TpPa@2400) is developed as a rapid lithium nucleator and sulfur species catalyst in fast-charging Li-S batteries. According to the adsorption energy and Bader charge results, Li atoms preferentially adsorb onto the surface of the TpPa@2400 separator, and the larger Bader charge value (0.52 |e|) of the TpPa@2400 separator also signifies faster lithium transport, promoting the nucleation of Li ions. Furthermore, density functional theory (DFT) theoretically demonstrates that the TpPa@2400 separator exhibits lower free energy for sulfur species interconversion. As a result, the TpPa@2400 separator enables the Li-Li symmetric cell with an extended cycle life of 6000 h at a current density/capacity of 10 mA cm^-²/10 mAh cm^-². The Li-S battery assembled using the TpPa@2400 separator delivers a high capacity of 1636.4 mAh/g at 0.1C and a rapid sulfur species conversion capacity of 513.8 mAh/g at 2C.

Keywords: COF-TpPa@2400 separator; Fast electrochemical kinetics; Fast-charging Li-S battery; Shuttle effect; Suppress Li dendrite formation.