Electrochemical lithium insertion behavior of combustion synthesized V ₂O ₅ cathodes for lithium-ion batteries

Sub-micron size vanadium pentoxide (V ₂O ₅) 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 V ₂O ₅ and the surface morphologies are studied by field emission scanning electron microscopy (FE-SEM). Electrochemical properties of the sintered V ₂O ₅ as a cathode in lithium-ion batteries are explored with respect to synthesis parameters using cyclic voltammetry and galvanostatic charge-discharge studies. The V ₂O ₅ particles obtained from 600C sintering temperature for 1 h exhibits a higher initial discharge capacity ∼320 mAh g ^-1 (∼2.2 Li per V ₂O ₅) between 1.75-4.0 V vs. LiLi 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 V ₂O ₅ particles. Ball milling procedure with or without carbon is also adopted to further reduce the particle size of V ₂O ₅ and related electrochemical properties are evaluated and described.