Defect engineering of a TiO2 anatase/rutile homojunction accelerating sulfur redox kinetics for high-performance Na-S batteries

Yue Xiao; Yelei Zheng; Ge Yao; Yuhang Zhang; Zhiqiang Li; Shoujie Liu; Fangcai Zheng

doi:10.1039/d4dt00745j

Defect engineering of a TiO₂ anatase/rutile homojunction accelerating sulfur redox kinetics for high-performance Na-S batteries

Dalton Trans. 2024 May 14;53(19):8168-8176. doi: 10.1039/d4dt00745j.

Authors

Yue Xiao¹, Yelei Zheng¹, Ge Yao¹, Yuhang Zhang¹, Zhiqiang Li¹, Shoujie Liu¹, Fangcai Zheng^{1

2}

Affiliations

¹ Institutes of Physical Science and Information Technology, School of Materials Science and Engineering, Key Laboratory of Structure and Functional Regulation of Hybrid Materials, Anhui University, Hefei, Anhui 230601, China. zfcai@mail.ustc.edu.cn.
² High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui, 230031, P. R. China. zfcai@mail.ustc.edu.cn.

PMID: 38680066
DOI: 10.1039/d4dt00745j

Abstract

Room-temperature sodium-sulfur (RT Na-S) batteries have the drawbacks of the poor shuttle effect of soluble sodium polysulfides (NaPSs) as well as slow sulfur redox kinetics, which result in poor cycling stability and low capacity, seriously affecting their extensive application. Herein, defect engineering is applied to construct rich oxygen vacancies at the interface of a TiO₂ anatase/rutile homojunction (O_V-TRA) to enhance sulfur affinity and redox reaction kinetics. Combining structural characterizations with electrochemical analysis reveals that O_V-TRA well alleviates the shuttle effect of NaPSs and precipitates the deposition and diffusion kinetics of Na₂S. Consequently, S/O_V-TRA provides excellent electrochemical performance with a reversible capacity of 870 mA h g^-1 at 0.1 C after 100 cycles and a long-term cycling capability of 759 mA h g^-1 at 1 C after 1000 cycles. This work provides an effective interfacial defect engineering strategy to promote the application of metal oxides in RT Na-S batteries.