Improved elevated temperature performance of al-intercalated V ₂O ₅ electrospun nanofibers for lithium-ion batteries

Al-inserted vanadium pentoxide (V ₂O ₅) nanofibers (Al-VNF) are synthesized by simple electrospinning technique. Powder X-ray diffraction (XRD) patterns confirm the formation of phase-pure structure. Elemental mapping and XPS studies are used to confirm chemical insertion of Al in VNF. Surface morphological features of as-spun and sintered fibers with Al-insertion are investigated by field-emission scanning electron microscopy (FE-SEM). Electrochemical Li-insertion behavior of Al-VNFs are explored as cathode in half-cell configuration (vs. Li) using cyclic voltammetry and galvanostatic charge-discharge studies. Al-VNF (Al _0.5V ₂O ₅) shows an initial discharge capacity of ∼250 mA h g ^-1 and improved capacity retention of >60% after 50 cycles at 0.1 C rate, whereas native VNF showed only ∼40% capacity retention at room temperature. Enhanced high current rate and elevated temperature performance of Al-VNF (Al _1.0V ₂O ₅) is observed with improved capacity retention (∼70%) characteristics. Improved performance of Al-inserted VNF is mainly attributed to the retention of fibrous morphology, apart from structural stabilization during electrochemical cycling.