Modified carbothermal synthesis and electrochemical performance of LiFePO4/C composite as cathode materials for lithium-ion batteries

摘要

LiFePCVC active materials were synthesized via a modified carbothermal method, with a low raw material cost and comparatively simple synthesis process. Rheolog-ical phase technology was introduced to synthesize the precursor, which effectively decreased the calcination temperature and time. The LiFePO4/C composite synthesized at 700 °C for 12 h exhibited an optimal performance, with a specific capacity about 130 mAh g~(-1) at 0.2C, and 70 mAh g~(-1) at 20C, respectively. It also showed an excellent capacity retention ratio of 96 % after 30 times charge-discharge cycles at 20C. EIS was applied to further analyze the effect of the synthesis process parameters. The as-synthesized LiFePO4/C composite exhibited better high-rate performance as compared to the commercial LiFePO4 product, which implied that the as-synthesized LiFePCVC composite was a promising candidate used in the batteries for applications in EVs and HEVs.