Electrochemical property of LiFePO₄/C composite cathode with different carbon sources

To improve the performance of battery cathode materials that consist of carbonaceous organic material, carbon coatings on lithium iron phosphate (LiFePO₄/C) materials were synthesized by different carbon sources. LiFePO₄/C was synthesized by a combination method of sol–gel and gas-phase diffused permeation. LiFeO₄/C materials were prepared by coating different carbon contents. High-performance composite materials were prepared by combining carbon with element doped by two modified methods. The elements of Fe and C came from Fe³⁺ and sucrose, glucose, citric acid. Thermogravimetry–differential thermal analysis (TG-DTA), X-ray diffractometer (XRD), scanning electron microscope (SEM), cycle voltammetry (CV), and charge–discharge test were used to characterize and test the surface morphology, structure, and electrochemical performance. The results show that LiFePO₄/C synthesized with sucrose has higher specific discharge capacity than the other materials. The specific discharge capacity of this material is 84.27 mAh·g⁻¹. The capacity retention could attain 94 % of the initial discharge capacity after 30 cycles, showing good electrochemical performance.