3-Aminopropyltriethoxysilane-Assisted Si@SiO2/CNTs Hybrid Microspheres as Superior Anode Materials for Li-ion Batteries

A silicon based composite (Si@SiO2/CNTs) with outstanding electrochemistry performance has been easily synthesized using a spray drying method; The composite microsphere is mainly made up of carbon nanotubes and the prepared nano silicon particles. With the help of a silane coupling agent, carbon nanotubes tightly intertwined with nano silicon particles and formed microspheres together. On the surface of the prepared nano silicon particles, a layer of oxide film plays a role as a barrier to reduce the rupture of the particles during the lithium intercalation/extraction process. In addition, the added twisted carbon nanotubes can help to maintain the conductive network, thus stabilizing the electrode working environment during the lithium intercalation/extraction process. As a superior anode material, an initial specific discharge capacity of approximately 2846.9 mAh g−1 with a coulombic efficiency of 86 % and a reversible specific capacity of 2035.9 mAh g−1 after 100 cycles at a constant density of 500 mA g−1 are obtained.