Synthesis and Properties of LiFePO4/LiAlO2 Nano Mesoporous Composite Cathode Materials

LiFePO4/LiAlO2 nano mesoporous composite cathode materials were synthesized via sot-gel method with citric acid as chelator, and with LiNO3, FeCl2 center dot 4H(2)O and NH4H2PO4 as starting materials. Structure and morphology of the composite cathode materials were analyzed by XRD and SEM. The results show that LiFePO4/LiAlO2 nano mesoporous composite cathode materials have the same solely olivine structure with no impurity. The electrochemical characteristics of LiFePO4/LiAlO2 nano mesoporous composite cathode materials were evaluated by means of the constant current charge-discharge. The results show that LiFePO4/LiAlO2 nano mesoporous composite cathode materials has a higher cycling capacity, and shows a high capacity retention upon cycling and high rate capability at 25 degrees C. At 0.1 C rate, its specific capacity of discharge is up to 159.1 mAh/g; at 5 C rate, its specific capacity of discharge is 111.8 mAh/g, and after 30 charge-discharge cycles, the capacity retention rates is 91%; as the content of LiAlO2 mesoporous materials increases, the capacity of the LiFePO4/LiAlO2 nano mesoporous composite cathode materials first increases and then decreases.