Combustion synthesis and electrochemical performance of Li2FeSiO4/C cathode material for lithium-ion batteries

A novel preparation technique was developed for synthesizing Li2FeSiO4/C nanoparticles through combustion of reaction mixtures containing silicon source, Li and Fe sources that operate as oxidizers and sucrose that act as a fuel. A systematic investigation of the synthesis parameters, such as the effect of the fuel content, on purity, morphology and electrochemical properties of the samples was performed. The samples were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), specific surface area (BET) and electrochemical measurements, respectively. Among the synthesized cathode materials, Li2FeSiO4 obtained with 1.5 mol of sucrose, showed the best electrochemical performance in terms of discharge capacity, cycling stability and rate capability. Discharge capacity of 130 mAh/g at C/20, 88 mAh/g at C/2 and 44 mAh/g at 2C were obtained with no capacity fading after 50 cycles.

► A novel preparation technique is developed for synthesizing Li2FeSiO4/C nanoparticles. ► Electrochemical performance depends on the quantity of sucrose. ► Li2FeSiO4 obtained with 1.5 mol of sucrose shows the best electrochemical performance. ► Particle size and purity are two key factors to enhance the electrochemical performance of Li2FeSiO4.