g-C3N4/MoO3 composite with optimized crystal face: A synergistic adsorption-catalysis for boosting cathode performance of lithium-sulfur batteries

Kaining Wen; Lin Huang; Laitao Qu; Teng Deng; Xinliang Men; Liping Chen; Juan Wang

doi:10.1016/j.jcis.2023.06.103

g-C₃N₄/MoO₃ composite with optimized crystal face: A synergistic adsorption-catalysis for boosting cathode performance of lithium-sulfur batteries

J Colloid Interface Sci. 2023 Nov:649:890-899. doi: 10.1016/j.jcis.2023.06.103. Epub 2023 Jun 25.

Authors

Kaining Wen¹, Lin Huang², Laitao Qu³, Teng Deng⁴, Xinliang Men⁵, Liping Chen⁶, Juan Wang⁷

Affiliations

¹ Xi'an Key Laboratory of Clean Energy, Shaanxi Key Laboratory of Nanomaterials and Nanotechnology, Xi'an University of Architecture and Technology, Xi'an, Shaanxi 710055, PR China. Electronic address: 737019653@qq.com.
² Xi'an Key Laboratory of Clean Energy, Shaanxi Key Laboratory of Nanomaterials and Nanotechnology, Xi'an University of Architecture and Technology, Xi'an, Shaanxi 710055, PR China. Electronic address: 2332084882@qq.com.
³ Xi'an Key Laboratory of Clean Energy, Shaanxi Key Laboratory of Nanomaterials and Nanotechnology, Xi'an University of Architecture and Technology, Xi'an, Shaanxi 710055, PR China. Electronic address: 951793627@qq.com.
⁴ Xi'an Key Laboratory of Clean Energy, Shaanxi Key Laboratory of Nanomaterials and Nanotechnology, Xi'an University of Architecture and Technology, Xi'an, Shaanxi 710055, PR China. Electronic address: dengteng2021@126.com.
⁵ Xi'an Key Laboratory of Clean Energy, Shaanxi Key Laboratory of Nanomaterials and Nanotechnology, Xi'an University of Architecture and Technology, Xi'an, Shaanxi 710055, PR China. Electronic address: menxinliang@126.com.
⁶ Xi'an Key Laboratory of Clean Energy, Shaanxi Key Laboratory of Nanomaterials and Nanotechnology, Xi'an University of Architecture and Technology, Xi'an, Shaanxi 710055, PR China. Electronic address: chenlp202203@xauat.edu.cn.
⁷ Xi'an Key Laboratory of Clean Energy, Shaanxi Key Laboratory of Nanomaterials and Nanotechnology, Xi'an University of Architecture and Technology, Xi'an, Shaanxi 710055, PR China. Electronic address: juanwang168@gmail.com.

PMID: 37390536
DOI: 10.1016/j.jcis.2023.06.103

Abstract

The commercial application of lithium-sulfur batteries (LSBs) has been seriously hindered by the shuttle effect of lithium polysulfides (LiPSs) and their slow redox kinetics. In this work, g-C₃N₄/MoO₃ composed of graphite carbon nitride (g-C₃N₄) nanoflake and MoO₃ nanosheet is designed and applied to modify the separator. The polar MoO₃ can form chemical bond with LiPSs, effectively slowing down the dissolution of LiPSs. And based on the principle of "Goldilocks", LiPSs will be oxidized by MoO₃ to thiosulfate, which will promote the rapid conversion from long-chain LiPSs to Li₂S. Moreover, g-C₃N₄ can promote the electron transportation, and its high specific surface area can facilitate the deposition and decomposition of Li₂S. What's more, the g-C₃N₄ promotes the preferential orientation on the MoO₃(021) and MoO₃(040) crystal planes, which optimizes the adsorption capacity of g-C₃N₄/MoO₃ for LiPSs. As a result, the LSBs with g-C₃N₄/MoO₃ modified separator with a synergistic adsorption-catalysis, can achieve an initial capacity of 542 mAh g^-1 at 4C with capacity decay rate of 0.0053% per cycle for 700 cycles. This work achieves the synergy of adsorption and catalysis of LiPSs through the combination of two materials, providing a material design strategy for advanced LSBs.

Keywords: Catalytic mechanism; Chemical adsorption; Lithium-sulfur batteries; Modified separator; Preferential orientation.