Synthesis Of V₂O₅ Cathode Materials And Its Effect On The Electrochemical Performances Of Rechargeable Magnesium Batteries

Rechargeable magnesium batteries possess a great potential in highefficiency energy storage because metal Mg possesses high energy density,abundant reserves,environmentally friendly nature and less tendency to form dendrites in most electrolytes.However,researches are still in infancy and mainly focus on cathode materials with high capacity and good cycle stability.In this paper,V₂O₅ were synthesized via DC Arc Plasma and hydrothermal route,and applied as cathodes for rechargeable magnesium batteries.XRD,SEM,nitrogen absorption/desorption isotherm were used to characterize the crystal structures and morphologies of products.Electrochemical performances such as cyclic voltammetry,galvanostatic charge-discharge property and rate capability were measured by related tests employed on batteries.The research results are mainly listed as follows:V₂O₅ powders were prepared by DC Arc Plasma,which consists of spherical nanoparticles in a diameter of 200 nm 2 ?m.The discharge capacity was 91.7 m Ah/g in the first cycle and severely decayed to 31.6 m Ah/g after 30 cycles.The poor cycle stability was attributed to the serious agglomeration of nanoparticles.V₂O₅ with different morphologies were obtained by adjusting related parameters in the hydrothermal method.Electrochemical tests showed that the material with high specific surface area and porous structure tends to display better performance.Assisted by CTAB surfactants,flower-like microspheres in a diameter of 3 ?m were synthesized.They were selfassembled by nanosheets in a thickness of about 26 nm.This structure presented superior electrochemical performance.The discharge capacity reached 126.2 m Ah/g in the first cycle and remained 91.3 m Ah/g after 60 cycles.The potential of discharge plateau was around 1.0 V.Meanwhile,EDS,XPS and XRD tests were used to study the valence and crystal structure of discharged and charged cathodes.As a result,reversible intercalation of Mg2+ ions into interplanar spacings of V₂O₅ lattice was confirmed.