Impact of pH on preparation of LiFePO4@C cathode materials by a sol-gel route assisted by biomineralization

A carbon-coated lithium iron phosphate (LiFePO4@C) cathode materials were synthesized by a sol-gel method assisted by biomineralization. Yeast acted as a template and biocarbon source. NH3 center dot H2O was used to adjust the pH in the preparation process, which effectively controlled the morphology. The LiFePO4@C synthesized at pH = 7 exhibited an optimal electrochemical performance, with a discharge capacity of 159.6 mAh/g at 0.1 C rate. Electrochemical impedance spectroscopy and cyclic voltammetry were applied to further analyze the impact of pH value. The optimized electrode also exhibited stable cycling characteristics. The improved electrochemical properties were ascribed to uniform spherical morphology and low electrochemical impedance. The biosynthetic sol-gel route can be desired to prepare LiFePO4@C cathode materials.