Defect-Engineered VS2 Electrocatalysts for Lithium-Sulfur Batteries

Li He; Xiaoya Zhang; Di Yang; Jiayu Li; Meiling Wang; Siyu Liu; Jingyi Qiu; Teng Ma; Junjie Ba; Yizhan Wang; Yingjin Wei

doi:10.1021/acs.nanolett.3c01838

Defect-Engineered VS₂ Electrocatalysts for Lithium-Sulfur Batteries

Nano Lett. 2023 Aug 23;23(16):7411-7418. doi: 10.1021/acs.nanolett.3c01838. Epub 2023 Aug 2.

Authors

Li He¹, Xiaoya Zhang¹, Di Yang¹, Jiayu Li², Meiling Wang¹, Siyu Liu³, Jingyi Qiu⁴, Teng Ma¹, Junjie Ba¹, Yizhan Wang¹, Yingjin Wei¹

Affiliations

¹ Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012, China.
² State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, China.
³ College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
⁴ Research Institute of Chemical Defence, Beijing 100191, China.

PMID: 37530698
DOI: 10.1021/acs.nanolett.3c01838

Abstract

Defective two-dimensional transition metal dichalcogenides can be effective electrocatalysts for Li-S batteries, but the relationship between defect types and battery performance is unclear. In this work, we designed S vacancy-type S_V-VS₂ and V self-intercalated-type V_I-VS₂ and measured their catalytic activities in Li-S batteries. Compared with self-intercalating V atoms, S vacancies accelerated Li⁺ diffusion and S_V-VS₂ as a Li⁺ "reservoir" promoted the sulfur conversion kinetics significantly. In addition, the presence of sulfur vacancies promoted the lithiation behavior of S_V-VS₂ during discharge, leading to an enhancement of the catalytic ability of S_V-VS₂. However, this lithiation phenomenon weakened the catalytic activity of V_I-VS₂. Overall, S_V-VS₂ had better adsorption and catalytic activity. Li-S batteries with S_V-VS₂-coated separators delivered high rate performance and excellent cycling stability, with a capacity decay rate of 0.043% over 880 cycles at 1.0 C. This work provides an effective strategy for designing efficient Li-S battery electrocatalysts using defect engineering.

Keywords: defects; electrocatalyst; lithium−sulfur battery; shuttling effect; vanadium dichalcogenide.