Deposition of silver nanoparticles into silicon/carbon composite as a high-performance anode material for Li-ion batteries

A silicon/silver/carbon (Si/Ag/C) composite with a core-core-shell structure has been synthesized via a simple method based on pyrolysis of an organic carbon source and silver mirror reaction. The Si and Ag nanoparticles are served as cores, while the porous amorphous carbon layer formed from pyrolysis of citric acid is served as shell. The porous amorphous carbon layer and highly conductive Ag nanoparticles can effectively alleviate the volume change of Si nanoparticles during lithiation/delithiation process and provide sufficient electrical conductivity for Si nanoparticles. As an anode material, the obtained Si/Ag/C composite exhibits excellent electrochemical performances, including high initial coulombic efficiency (85.6 % at 200 mA g⁻¹), stable cycling performance (a discharge capacity of 2006.3 mA g⁻¹ at 200 mA g⁻¹ after 100 cycles), and excellent rate performance (a discharge capacity of 826.4 mA h g⁻¹ at 3 A g⁻¹). This simple method may open up an effective way to make other anode and cathode materials for commercial lithium-ion battery.