Efficient capture and conversion of polysulfides by zinc protoporphyrin framework-embedded triple-layer nanofiber separator for advanced Li-S batteries

Zhiheng Ren; Jixiao Li; Yangyang Gong; Xianliang Li; Jianneng Liang; Yongliang Li; Chuanxin He; Qianling Zhang; Xiangzhong Ren

doi:10.1016/j.jcis.2021.12.003

Efficient capture and conversion of polysulfides by zinc protoporphyrin framework-embedded triple-layer nanofiber separator for advanced Li-S batteries

J Colloid Interface Sci. 2022 Mar:609:43-53. doi: 10.1016/j.jcis.2021.12.003. Epub 2021 Dec 2.

Authors

Zhiheng Ren¹, Jixiao Li², Yangyang Gong², Xianliang Li², Jianneng Liang³, Yongliang Li², Chuanxin He², Qianling Zhang², Xiangzhong Ren⁴

Affiliations

¹ College of Chemistry and Environmental Engineering, International Joint Research Center for Molecular Science, Shenzhen University, Shenzhen, Guangdong 518060, PR. China; Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, PR. China.
² College of Chemistry and Environmental Engineering, International Joint Research Center for Molecular Science, Shenzhen University, Shenzhen, Guangdong 518060, PR. China.
³ College of Chemistry and Environmental Engineering, International Joint Research Center for Molecular Science, Shenzhen University, Shenzhen, Guangdong 518060, PR. China. Electronic address: jianneng1991@gmail.com.
⁴ College of Chemistry and Environmental Engineering, International Joint Research Center for Molecular Science, Shenzhen University, Shenzhen, Guangdong 518060, PR. China. Electronic address: renxz@szu.edu.cn.

PMID: 34890950
DOI: 10.1016/j.jcis.2021.12.003

Abstract

The practical application of Lithium-sulfur (Li-S) batteries is significantly inhibited by (i) the notable 'shuttle effect' of lithium polysulfides (LiPS), (ii) the corrosion of the lithium interface, and (iii) the sluggish redox reaction kinetics. The functional separator in the Li-S battery has the potential to provide the perfect solution to these problems. Herein a triple-layer multifunctional PVDF-based nanofiber separator, which contains GoTiN/PVDF layer on the top and bottom and ZnTPP/PVDF layer on the middle, is designed. The polarity and porous structure of this multifunctional separator can greatly improve the wettability of electrolytes and enhance the transportation of Li⁺. With the zinc-based porphyrin framework (ZnTPP) structure, this separator has a strong chemisorption and LiPS conversion ability, which greatly prevent the 'shuttle effect'. Consequently, the designed multilayer separator showed excellent electrochemical performance. As a result, the cell with GoTiN@ZnTPP@GoTiN nanofiber membrane displayed an initial discharge capacity of 1180 mAh/g with a benign capacity retention of 65.9% at 0.5C and high coulombic efficiency of more than 98.5% after 100 cycles. Even at 2C, it can still release a capacity of 798 mAh/g. Moreover, the remarkable capacity of 591 mAh/g could be achieved with a high sulfur load of 5.76 mg/cm² under a current density of 0.1C. Based on these merits, this novel and scalable multifunctional separator is a promising candidate to replace the conventional PP separator for advanced Li-S batteries to deal with various challenges.

Keywords: Lithium-sulfur battery; Multifunctional separator; Polysulfides; Shuttle effect; Zinc protoporphyrin.