Abstract
•Synthesizing VSe2 via a facile and low-cost one-step hydrothermal process.•Establishing Mg/VSe2 ion battery with a halogen-free electrolyte.•Structure evolution of VSe2 at different electrochemical states.
Vanadium diselenide (VSe2) has attracted many qualifications and has been nominated as a promising cathode for magnesium battery application. Herein, VSe2 nanocomposites are synthesized hydrothermally as a cathode in halogen-free electrolyte (HFE) (0.69 M Mg(NO3)2·6H2O in ACN:G4(∼2:1). The full cell of Mg/VSe2 contains HFE electrolyte provides an initial discharge capacity ∼ 240.8 mAh g−1 at 20 μA cm−2, and a capacity retention capacity of ∼ 50 mAh g−1 after 40 cycles. X-ray diffraction, scanning electron microscope, Raman spectra, electrochemical impedance spectroscopy, and galvanostatic discharge are used to investigate the structure, morphology, and Mg ratio evolution of the VSe2 cathode at different electrochemical states.