Modification of a LiFePO4 cathode for lithium ion batteries by carbon coating and copper doping

The effects of a carbon coating and copper doping on the electrochemical performance and tap density of a LiFePO4 cathode for lithium ion batteries were investigated by XRD,SEM,charge/discharge cycle tests,rate tests and tap density tests. Results showed that the average discharge capacity of LiFePO4/C and LiFe0.95Cu0.05PO4 were 147 mAh/g and 131 mAh/g respectively. The capacity fading rate of LiFe0.95Cu0.05PO4 was much larger than that of LiFePO4/C in a high-rate discharging test. The electrochemical performance of LiFePO4/C was better than that of LiFe0.95Cu0.05PO4,but the tap density of the latter was 1.5 times as large as that of the former.