Abstract: LiFePO₄/Li₃V₂(PO₄)₃composite cathode materials with a series of mass ratios were synthesized using the liquid-phase co-precipitation method and carbon thermal-reduction process to improve the electronic conductivity of LiFePO₄ cathodes. X-ray diffraction, scanning electron microscopy, constant-current charge and discharge testing, and other analytical methods were used to analyze the phase composition, morphology, and electrochemical performance of the composites. When the mass ratio of LiFePO₄ and Li₃V₂(PO₄)₃ was 6:4, the composite exhibited regular morphology, higher crystallinity, and the best electrochemical performance: the discharge capacity was 148, 130.5, 121.5,and 112.3 mA·h·g-1 at rates of 0.1C, 1.0C, 2.0C, 5.0C, and 10.0C, respectively, and the capacity remained above 98.5% after 100 cycles at 1C. This effectively solves the problem of low conductivity of the LiFePO₄ material and will accelerate its application in power lithium-ion batteries.

Key words: lithium-ion batteries, cathode material, liquid-phase co-precipitation, rate capability, cycle life