The effect of carbon coating on the electrochemical performance of nanosized Li<inf>2</inf>FeSiO<inf>4</inf> cathode materials

Abstract

Carbon-coated Li2FeSiO4/C cathode materials have been synthesized through a modified ball-milling pro- cess. The physical characterizations of Li2FeSiO4 were conducted by using X-ray powder diffraction, field-emission scanning electron microscopy and transmission electron microscopy techniques. Field-emission scanning electron microscopy and transmission electron microscopy images revealed that Li2FeSiO4/C consists of nanosized parti- cles coated with an amorphous carbon layer. The electrochemical performances of Li2FeSiO4/C cathode materials were evaluated through fully assembled lithium batteries via cyclic voltammetry, charge/discharge test and electro- chemical impedance spectroscopy. The Li2FeSiO4/C cathode materials showed a much improved electrochemical performance in terms of higher specific capacity, better cycling performance and less charge transfer resistance than that of the pristine Li2FeSiO4