Oxygen vacancy-mediated amorphous GeOx assisted polysulfide redox kinetics for room-temperature sodium-sulfur batteries

Qiuyang Ma; Qiqi Liu; Zhongyuan Li; Jun Pu; Jawayria Mujtaba; Zhen Fang

doi:10.1016/j.jcis.2022.09.071

Oxygen vacancy-mediated amorphous GeO_x assisted polysulfide redox kinetics for room-temperature sodium-sulfur batteries

J Colloid Interface Sci. 2023 Jan;629(Pt B):76-86. doi: 10.1016/j.jcis.2022.09.071. Epub 2022 Sep 17.

Authors

Qiuyang Ma¹, Qiqi Liu¹, Zhongyuan Li¹, Jun Pu², Jawayria Mujtaba³, Zhen Fang⁴

Affiliations

¹ College of Chemistry and Materials Science, Key Laboratory of Electrochemical Clean Energy of Anhui Higher Education Institutes, Anhui Normal University, Wuhu 241000, PR China; Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Normal University, Wuhu 241000, PR China.
² College of Chemistry and Materials Science, Key Laboratory of Electrochemical Clean Energy of Anhui Higher Education Institutes, Anhui Normal University, Wuhu 241000, PR China; Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Normal University, Wuhu 241000, PR China. Electronic address: jpu@ahnu.edu.cn.
³ College of Chemistry and Materials Science, Key Laboratory of Electrochemical Clean Energy of Anhui Higher Education Institutes, Anhui Normal University, Wuhu 241000, PR China; Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Normal University, Wuhu 241000, PR China. Electronic address: jawayria.m@icloud.com.
⁴ College of Chemistry and Materials Science, Key Laboratory of Electrochemical Clean Energy of Anhui Higher Education Institutes, Anhui Normal University, Wuhu 241000, PR China; Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Normal University, Wuhu 241000, PR China; Anhui Provincial Engineering Laboratory for New-Energy Vehicle Battery Energy-Storage Materials, Wuhu 241000, PR China. Electronic address: fzfscn@mail.ahnu.edu.cn.

PMID: 36152582
DOI: 10.1016/j.jcis.2022.09.071

Abstract

The practical applications of room-temperature sodium-sulfur (RT Na-S) batteries have been greatly hindered by the natural sluggish reaction kinetics of sulfur and the shuttle effect of sodium polysulfide (NaPSs). Herein, oxygen vacancy (OV)-mediated amorphous GeO_x/nitrogen doped carbon (donated as GeO_x/NC) composites were well designed as sulfur hosts for RT Na-S batteries. Experimental and density functional theory studies show that the introduction of oxygen vacancies on GeO_x/NC can effectively immobilize polysulfides and accelerate the redox kinetics of polysulfides. Meanwhile, the micro-and mesoporous framework, acting as a reactor for storing active S, is conducive to alleviating the expansion of S during the charging/discharging process. Consequently, the S@GeO_x/NC cathode affords a reversible capacity of 1017 mA h g^-1 at 0.1 A g^-1 after 100 cycles, outstanding rate capability of 333 mA h g^-1 at 10.0 A g^-1 and long lifespan cyclability of 385 mAh g^-1 at 1 A g^-1 after 1200 cycles. This work furnishes a new way for the rational design of metal oxides with oxygen vacancies and boosts the application for RT Na-S batteries.

Keywords: GeO(x); Oxygen vacancies; Sodium polysulfide; Sodium-sulfur batteries; Sulfur host.