Controlled synthesis of yolk–mesoporous shell Si@SiO2 nanohybrid designed for high performance Li ion battery

Abstract

A yolk–mesoporous shell Si@SiO₂ nanohybrid (YMSSN) with void space between the Si core and the SiO₂ outer shell up to tens of nanometers has been prepared in this work by a vesicle template method. Commercially available Si nanoparticles (Nps) are incorporated into mesoporous hollow colloidal SiO₂ spheres (MHSS), which are designed to accommodate a large volume change of Si cores and facilitate diffusion of lithium ions through the pore channels during the lithiation/delithiation process. By adjusting the concentration of surfactants and tetraethyl orthosilicate (TEOS), well-dispersed YMSSN with controllable shell thickness can be obtained. This intriguing structure shows high reversible capacity (∼687 mA h g⁻¹), good Coulombic efficiency (95.63%) and excellent rate-capability.