关键词:

Li3PO4;水热法;LiFePO4, 改性

Abstract:

LiFePO4, as cathode material of lithium ion batteries, which was suitable for discharge at high current density, was prepared by carbon-coating and Cu2+-doping modification of pure LiFePO4 synthesized from self-prepared Li3PO4 and FeSO4•7H2O at hydrothermal condition.The effects of hydrothermal temperature on electrochemical property and its phase composition, structure and morphology, characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM)and scanning electron microscopy (SEM), were studied.The electrochemical performance of Cu ²⁺ -doped samples at room and low temperature was also investigated.The results show that the carbon-coating composite LiFePO4/C (LFP/C)synthesized hydrothermally at 200℃ for 24 h is of specific capacity of 140.7 mAh·g^-1 under discharge current density of 1C (150 mA·g^-1）. The performance could be further improved after LFP200/C was doped by Cu ²⁺ , i.e.the specific capacity was 150.3mAh·g^-1 and 108.7mAh·g-1 at room temperature with discharge current density 1 C and 10 C, and 97 mAh·g^-1 at -30℃, respectively.

Key words:

Li3PO4;水热法;LiFePO4, 改性