Interface Engineering of Fe7S8/FeS2 Heterostructure in situ Encapsulated into Nitrogen-Doped Carbon Nanotubes for High Power Sodium-Ion Batteries

Penghao Song; Jian Yang; Chengyin Wang; Tianyi Wang; Hong Gao; Guoxiu Wang; Jiabao Li

doi:10.1007/s40820-023-01082-w

Interface Engineering of Fe₇S₈/FeS₂ Heterostructure in situ Encapsulated into Nitrogen-Doped Carbon Nanotubes for High Power Sodium-Ion Batteries

Nanomicro Lett. 2023 Apr 30;15(1):118. doi: 10.1007/s40820-023-01082-w.

Authors

Penghao Song¹, Jian Yang^{1

2}, Chengyin Wang¹, Tianyi Wang³, Hong Gao⁴, Guoxiu Wang⁵, Jiabao Li⁶

Affiliations

¹ College of Chemistry and Chemical Engineering, Yangzhou University, 180 Si-Wang-Ting Road, Yangzhou, 225002, Jiangsu, People's Republic of China.
² Key Lab of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang, 330022, People's Republic of China.
³ College of Chemistry and Chemical Engineering, Yangzhou University, 180 Si-Wang-Ting Road, Yangzhou, 225002, Jiangsu, People's Republic of China. wangty@yzu.edu.cn.
⁴ Centre for Clean Energy Technology, Faculty of Science, University of Technology Sydney, PO Box 123, Broadway, NSW, 2007, Australia. hong.gao@uts.edu.au.
⁵ Centre for Clean Energy Technology, Faculty of Science, University of Technology Sydney, PO Box 123, Broadway, NSW, 2007, Australia. guoxiu.wang@uts.edu.au.
⁶ College of Chemistry and Chemical Engineering, Yangzhou University, 180 Si-Wang-Ting Road, Yangzhou, 225002, Jiangsu, People's Republic of China. jiabaoli@yzu.edu.cn.

Abstract

Heterostructure engineering combined with carbonaceous materials shows great promise toward promoting sluggish kinetics, improving electronic conductivity, and mitigating the huge expansion of transition metal sulfide electrodes for high-performance sodium storage. Herein, the iron sulfide-based heterostructures in situ hybridized with nitrogen-doped carbon nanotubes (Fe₇S₈/FeS₂/NCNT) have been prepared through a successive pyrolysis and sulfidation approach. The Fe₇S₈/FeS₂/NCNT heterostructure delivered a high reversible capacity of 403.2 mAh g^-1 up to 100 cycles at 1.0 A g^-1 and superior rate capability (273.4 mAh g^-1 at 20.0 A g^-1) in ester-based electrolyte. Meanwhile, the electrodes also demonstrated long-term cycling stability (466.7 mAh g^-1 after 1,000 cycles at 5.0 A g^-1) and outstanding rate capability (536.5 mAh g^-1 at 20.0 A g^-1) in ether-based electrolyte. This outstanding performance could be mainly attributed to the fast sodium-ion diffusion kinetics, high capacitive contribution, and convenient interfacial dynamics in ether-based electrolyte.

Keywords: Ester-based electrolyte; Ether-based electrolyte; Heterostructure; Iron sulfides; Nitrogen-doped carbon nanotubes.