Construction of VS2 with sulfur vacancy as a superior cathode for lithium-ion batteries

As a typical transition-metal dichalcogenide (TMD), vanadium disulfide (VS2) is an excellent candidate for cathode material in lithium-ion batteries due to its metallic properties and large interlayer spacing. But they often suffer from low intercalation capacity and sluggish kinetics processes, significantly limiting their practical application. Herein, the cetyltrimethylammonium bromide (CTAB) is employed in the synthesis process to construct the sulfur (S) vacancy in VS2. The sulfur vacancy could improve its intercalation capacity and kinetics performance. In this structure, the interlayer vacancy defects could provide extra intercalation sites to improve intercalation capacity. It could induce multiple migration paths for lithium-ion (Li+) and electron (e-), enabling fast Li + migration and rapid charge transfer. It also presents favorable rate performance with a high pseudocapacitance contribution during a typical intercalation reaction. The above positive behaviors significantly promote the kinetics performance of VS2-x as a cathode material for lithium-ion batteries (smaller charge transfer resistance and high Li+ diffusion rate). Finally, this material could provide a high storage capacity of 140 mAh g  1 after 180th and favorable rate performance (55.5 mAh g  1 at 1A g  1). This work could provide a reference for improving TMD's electrochemical performance and expanding their applications.

Automated summary

In this study, cetyltrimethylammonium bromide (CTAB) was used to improve the performance of vanadium disulfide (VS2) and enhance the storage capacity and rate performance of lithium-ion batteries as cathode materials.