Revisiting the electrochemical impedance behaviour of the LiFePO4/C cathode

In the present work, the electrochemical behaviour of LiFePO4/C electrode has been reported. Specially, the electrochemical impedance spectroscopies (EIS) have been studied in detail. The discharge capacity-is more than 120 mAh/g. There are two semicircles being found in the Nyquist plot for the cycled electrode and one semicircle for the as-prepared electrode. It is found that the interface capacitance is in an order of magnitude of 10 mu F/cm(2) for the high-frequency semicircle, while for the second semicircle the interface capacitance is 5.3 similar to 45.4 x 10(3) mu F/cm(2). It could be concluded that the high-frequency semicircle is to correspond to the charge transfer process. The function of the carbon layer is also briefly discussed.