Highly enhanced low-temperature performances of LiFePO4/C cathode materials prepared by polyol route for lithium-ion batteries

Although LiFePO4/C has been successfully put into practical use in lithium-ion batteries equipped on new energy vehicles, its unsatisfactory low temperature results in poor low performance of lithium-ion batteries, leading to a much smaller continue voyage course at extreme environments with low temperature for electric vehicles. In this paper, the electrochemical performance of the LiFePO4/C prepared by polyol route was investigated at a temperature range from 25 to -20 A degrees C. Compared to commercial ones, as-prepared LiFePO4/C shows a much better low-temperature performance with a reversible capacity of 30 mA h g(-1) even at 5 C under -20 A degrees C and a capacity retention of 91.1 % after 100 cycles at 0.1 C under 0 A degrees C. Moreover, high-resolution transmission electron microscopy (HRTEM) revealed that this outstanding performance at low temperatures could be assigned to uniform carbon coating and the nano-sized particles with a highly crystalline structure.