Abstract:Nanosphere-like Li₂FeSiO₄/C was synthesized via a solution method using sucrose as carbon sources under a mild condition of time-saving and energy-saving, followed by sintering at high temperatures for crystallization. The amount of carbon in the composite is less than 10% (mass fraction), and the X-ray diffraction result confirms that the sample is of pure single phase indexed with the orthorhombic Pmn2₁ space group. The particle size of the Li₂FeSiO₄/C synthesized at 700 °C for 9 h is very fine and spherical-like with a size of 200 nm. The electrochemical performance of this material, including reversible capacity, cycle number, and charge-discharge characteristics, were tested. The cell of this sample can deliver a discharge capacity of 166 mA·h/g at C/20 rate in the first three cycles. After 30 cycles, the capacity decreases to 158 mA·h/g, and the capacity retention is up to 95%. The results show that this method can prepare nanosphere-like Li₂FeSiO₄/C composite with good electrochemical performance.

Key words: lithium-ion batteries; cathode material; Li₂FeSiO₄/C; solution method