Influence of Sulfur-Modified Vanadium Pentoxide by Solid Phase Sintering Method on Electrochemical Performance of Cathode Materials for Lithium-Ion Batteries

Vanadium pentoxide (V2O5) is a common cathode material for lithium-ion batteries, and its chemical composition and structure can seriously affect the electrochemical performance of the batteries. V2O5 is modified by sulfur with solid phase sintering method, and its physical property and electrochemical performance are studied. Physical characterization shows that after sulfur modification, V2O5 changes to low-valence vanadium oxide (V6O13 or VO2), and some free sulfur is observed inside the vanadium oxide molecule in high proportion. Electrochemical test results show that when the proportion of sulfur is 10%, vanadium oxide cathode has the lowest charge resistance and the most excellent reversibility. Specific capacity of 188.87, 146.60, 130.42, and 110.86 mAh g(-1) is achieved at 100, 200, 300, and 500 mA g(-1) current density. After 300 cycles, its electrochemical performance remains stable and has the highest specific capacity.