Electrochemical Lithium Insertion Behavior of Combustion Synthesized V2O5 Cathodes for Lithium-Ion Batteries

Abstract

Sub-micron size vanadium pentoxide (V2O5) particles are synthesized by novel urea assisted combustion method. Comprehensive characterization and electrochemical studies related to sintering temperature and duration are presented. X-ray diffraction (XRD) patterns showed the formation of pure-phase V2O5 and the surface morphologies are studied by field emission scanning electron microscopy (FE-SEM). Electrochemical properties of the sintered V2O5 as a cathode in lithium-ion batteries are explored with respect to synthesis parameters using cyclic voltammetry and galvanostatic charge-discharge studies. The V2O5 particles obtained from 600°C sintering temperature for 1 h exhibits a higher initial discharge capacity ∼320 mAh g−1 (∼2.2 Li per V2O5) between 1.75–4.0 V vs. Li/Li+ at 0.1 C rate and shows good capacity retention of >70% after 50 cycles. Electrochemical impedance spectroscopy (EIS) studies show that the urea combustion method enables increased Li+ ion diffusion pathways and electro-active surface area in V2O5 particles. Ball milling procedure with or without carbon is also adopted to further reduce the particle size of V2O5 and related electrochemical properties are evaluated and described.