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

Vanadium pentoxide (V 2 O 5 ) is a common cathode material for lithium‐ion batteries, and its chemical composition and structure can seriously affect the electrochemical performance of the batteries. V 2 O 5 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, V 2 O 5 changes to low‐valence vanadium oxide (V 6 O 13 or VO 2 ), 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.