Effect of sintering temperature on the lithium storage performance of LiFePO4-C nanocomposite powders synthesized by ultrasonic spray pyrolysis technique

Research on the high rate, safe, durable, and cheap electrode materials in the field of lithium ion batteries (LIBs) is one of the hot topics in the field. In this regards, some anodic and cathodic materials having the foregoing merits were introduced, among which LiFePO4 is one of the promising cathodic materials. In this study, LiFePO4-C nanocomposite was synthesized by ultrasonic spray pyrolysis technique. A precursor solution composed of LiNO3, Fe(NO3)3.9H2O,H3PO4 and sucrose dissolved in distilled water was ultrasonically sprayed into an inert atmosphere tube furnace at 600 C, and the synthesized powders were collected and sintered at 600 to 800 C in N2 +5%H2 atmosphere. The electrochemical performances of the synthesizedsamples were examined with charge-discharge, cyclic voltammetry and electrochemical impedance spectroscopy tests. The sample sintered at 700C showed the best electrochemical performance as follows: The initial discharge capacity of 136 mAh/g at 0.1 C rate and 104mAh/g at 100mAg-1 rate, keeping a capacity retention ratio of 90% after 50 cycles. While, without sintering process, the initial discharge capacity was 65 mAh/g at 0.1C rate and 32 mAh/g at 100mAg-1 rate, and capacity retention ratio of 84% was observed after 50 cycles.

کلیدواژه ها:

Spray pyrolysis ، LiFePO4 ، Lithim-ion battery ، Cathode