The doped effect analysis of lithium iron phosphate at Li and Fe sites

The modification of metal ion doping at different sites in LiFePO4 was investigated in this paper.Co-precipitation method was used to synthesize LiFePO4 positive materials doped with Mg2+,Mo6+ at Fe site and Li site. The characteristic and performance of synthesized material were studied by using XRD,XPS,cyclic voltammetry,charge-discharge curve.Results showed that Mg2+ and Mo6+ ions can be doped in Fe site and Li site of LiFePO4,and the doping will not affect its olivine structure.The electrochemical property and charge-discharge performance of materials were obviously improved whatever site doped in,and the material doped in Fe site is better than that in Li site.The doping mechanism was discussed based on crystal structure and semiconductor theory.