Low temperature performance of LiFePO4 cathode is investigated by charge/discharge test and electrochemical impedance spectroscopy (EIS). The results show that the effect of charge temperature on charge and discharge capacity is very slight in range of -20 to 20 degrees C and the influence of discharge temperature on discharge capacity is more greater. At -20 degrees C, LiFePO4 cathode only retains less than 50% of the discharge capacity obtained at 20 degrees C. We can extend time durability of constant-voltage charge to improve the discharge capacity, especially below -20 degrees C. Charge/discharge dependence on temperature is studied by EIS and the results show that the charge-transfer resistance (R-ct) becomes significantly higher than bulk resistance (R-b) and solid-state interface resistance (R-sei) as temperature decreases, no matter in charge or discharge state. The R-ct value of charged state is also found to be much lower than that of discharge state. Charge-transfer activation energies of charge and discharge are calculated to be 33.80 and 40.90 kJ mol(-1), indicating that the extra energy barrier is the main thermodynamic factor causing the sluggish discharge behavior at low temperature. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.