Abstract:

Molar ratio of Li and Fe，glucose quantity，sintering time and temperature are four factors influencing the electrochemical properties of LiFePO₄/C cathode material. By using an improved solid-state reaction，an orthogonal test with four factors and three levers was designed to optimize the synthesis conditions of LiFePO₄. Some cathode materials with excellent electrochemical performance were synthesized under these optimized conditions. Structure and electrochemical properties of the produced materials were caracterized by using XRD，SEM，cyclic voltammetry and electrochemical impedance spectra. Without using ball milling，this improved solid state reaction method is propitious to industrial production. The first discharge specific capacities of the optimized samples were 133.2 mAh/g at 0.2 C and 112.5 mAh/g at 1.0 C under room temperature. After 30 cycles，the capacity at 0.2 C remained stable at about 133.1 mAh/g and fell down to 106.8 mAh/g at 1.0 C.