Structural and electrochemical properties of LiFe1-aEuroparts per thousand3x/2Bi x PO4/C synthesized by sol-gel

In this study, LiFe1 -aEuro parts per thousand 3x/2Bi (x) PO4/C cathode material was synthesized by sol-gel method. From XRD patterns, it was found that the Bi-doped LiFePO4/C cathode material had the same olivine structure with LiFePO4/C. SEM studies revealed that Bi doping can effectively decrease the particle sizes. It shortened Li+ diffusion distance between LiFePO4 phase and FePO4 phase. The LiFe0.94Bi0.04PO4/C powder exhibited a specific initial discharge capacity of about 149.6 mAh g(-1) at 0.1 rate as compared to 123.5 mAh g(-1) of LiFePO4/C. EIS results indicated that the charge-transfer resistance of LiFePO4/C decreased greatly after Bi doping.