Performance of LiFePO_4/C synthesized by hydrothermal with different reaction system

Cathode material carbon coated lithium iron phosphate(LiFePO4/ C) was prepared by hydrothermal method with surfactant.The morphology,structure and electrochemical performance of the products were characterized by Fourier transform infrared spectroscopy(FT-IR),XRD,thermogravimetric(TG),SEM,galvanostatic charge-discharge and electrochemical impedance spectroscopy(EIS) tests.LiFePO4/ C samples were small particles with pure phase and regular shape.LiFePO4/ C particles showed different morphology and grain size when the surfactant changed.LiFePO4/ C samples prepared with PVP and PEG-400 could deliver the initial discharge specific capacity of 154.1 mAh/g and 145.6 mAh/g at 0.1 C when cycled in 2.0 ~ 4.2 V.When cycle 24 times,the capacity retention at 0.5 C was 71% and 75%,respectively,the capacity retention at 1.0 C was 65% and 62%,respectively.