Preparation and characterization of electrospun LiFePO₄/carbon complex improving rate performance at high C-rate

摘要

LiFePO₄/carbon complexes were prepared by electrospinning to improve rate performance at high C-rate and their electrochemical properties were investigated to be used as a cathode active material for lithium ion battery. The LiFePO₄/carbon complexes were prepared by the electrospinning method. The prepared samples were characterized by SEM, EDS, XRD, TGA, electrometer, and electrochemical analysis. The LiFePO₄/carbon complexes prepared have a continuous structure with carbon-coated LiFePO₄ and the LiFePO₄ in LiFePO₄/carbon complex has improved thermal stability from carbon coating. The conductivity of LiFePO₄/carbon complex heat-treated at 800 °C is measured as 2.23 × 10−2 S cm−1, which is about 106–107 times more than that of raw LiFePO₄. The capacity ratio of coin cell manufactured from raw LiFePO₄ is 40%, whereas the capacity ratio of coin cell manufactured from LiFePO₄/carbon complex heat-treated at 800 °C is 61% (10 C/0.1 C). The improved rate performance of LiFePO₄/carbon complex heat-treated at 800 °C is due to the carbon coating and good electrical connection.