材料期刊网

Doping modification of electrode materials is a sought-after strategy to improve their electrochemical performance in the secondary batteries field.Herein,polyanion (BO3)3--doped Li3V2(PO4)3 cathode materials were successfully synthesized via a wet coordination method.The effects of (BO3)3-doping content on crystal structure,morphology and electrochemical performance were explored by X-ray diffraction (XRD),scanning electron microscopy (SEM),cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS).All the asprepared samples have the same monoclinic structure;among them,Li3V2(PO4)2.75(BO3)o.15 sample has relatively uniform and optimized particle size.In addition,this sample has the highest discharge capacity and the best cycling stability,with an initial discharge capacity of 120.4 mAh·g-1,and after 30 cycles at a rate of 0.1C,the discharge capacity still remains 119.3 mAh·g-1.It is confirmed that moderate polyanion (BO3)3-doping can rearrange the electronic structure of the bulk Li3V2(PO4)3,lower the charge transfer resistance and further improve the electrochemical behaviors.