High-rate and elevated temperature performance of electrospun V₂O₅ nanofibers carbon-coated by plasma enhanced chemical vapour deposition

Vanadium pentoxide (V₂O₅) nanofibers (VNF) are synthesized by electrospinning technique and homogeneously coated with carbon by plasma enhanced chemical vapour deposition. The morphological features of the VNF are analyzed by field emission scanning and transmission electron microscopy showed the presence of carbon layer over the VNF crystallites. Powder X-ray diffraction (XRD) patterns of the calcined nanofibers reveal the formation of V₂O₅ phase. Electrochemical Li-insertion behaviors of VNFs are explored as cathode in half-cell configuration by means of both potentiostatic and galvanostatic measurements. Carbon-coated VNF (C-VNF) showed the slightly less initial discharge capacity of ~300mAhg^-1 with improved capacity retention of >65% after 50 cycles at 0.1C rate, whereas native VNF showed only ~40% capacity retention under the same testing conditions. Enhanced high rate and elevated temperature performance of C-VNF is noted with overall capacity and capacity retention (>60%) characteristics than native fibers. Carbon-coating enables improved electronic conductivity profiles and prevents undesired side reactions with electrolyte counterpart without hindering the Li-ion mobility reflected in the superior battery performance of C-VNF.