Synthesis, characterization and electrochemical performance of Li2FeSiO4/C cathode materials doped by vanadium at Fe/Si sites for lithium ion batteries

► Li2FeSiO4/C samples doped by vanadium at Fe/Si sites have been successfully prepared. ► Vanadium doping at Fe/Si sites have different influence on the cell parameter. ► The oxidation state of vanadium doped at Fe sites is +3, whereas is +5 at Si sites. ► Li2FeSi0.9V0.1O4/C material exhibits excellent electrochemical performance.