Controllable fabrication of vanadium selenium nanosheets for a high-performance Na-ion battery anode

Vanadium selenium has gained attention as a potential anode for sodium-ion batteries (SIBs) due to the tunable crystal structure, effective channels for Na⁺ diffusion, and high theoretical specific capacity. However, the pursuit of vanadium selenium remains an enormous challenge. Herein, we demonstrated that V₂Se₉ nanosheets could be fabricated facilely and efficiently via a one-pot synthesis method with the careful selection of the solvent/surfactant. The V₂Se₉ anode have demonstrated excellent electrochemical performance for SIBs. An intercalation and conversion mechanism of Na-storage in V₂Se₉ were clarified by ex situ X-ray diffraction. This work develops an effective strategy to fabricate transition metal chalcogenides for high-performance sodium storage.