Synthesis, characterization and electrochemical performance of Li2FeSiO4/C for lithium-ion batteries

Abstract

Li₂FeSiO₄/C was synthesized from a mixture of Li₂SiO₃, FeC₂O₄·2H₂O, citric acid and sucrose via a simple solid-state, high-temperature treatment. The Li₂SiO₃ produced via the simple ball-milling of LiOH·H₂O and H₂SiO₃ can simultaneously provides Li and Si. The resulting Li₂FeSiO₄/C sample was characterized via X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, transmission electron microscopy, and electrochemical measurements. The amount of carbon coated on the Li₂FeSiO₄/C particles is approximately 8.98 wt%, which can increase the conductivity of the materials. However, byproduct LiFeO₂ appears in the as-synthesized sample. The obtained Li₂FeSiO₄/C sample exhibits an initial discharge capacity that exceeds 170 mA h g⁻¹ and a cyclic discharge capacity of approximately 120 mA h g⁻¹ at a current density of 10 mA g⁻¹ under room temperature.