Scalable coral‐like silicon powders with three‐dimensional interconnected structures for lithium ion battery anodes

Abstract

Silicon has attracted a lot of attention as a potential anode material for next‐generation lithium ion batteries (LIBs) because of its high energy density, high theoretical capacity, and abundance. Herein, we introduce an effortless synthesis of coral‐like silicon powders with a three‐dimensional (3D) interlinked network using a scalable method that consist of magnesiothermic reduction and chemical vapor deposition. The porous structure achieved by silicon nanospheres can create room for the volume expansion and alleviate the built strain that would occur upon lithiation. In addition, intertwined coral‐like framework provides a shortened path for lithium ion diffusion, which can improve the ionic conductivity of the cells. At a high current rate of C/2, a reversible capacity of 3172 mAh g −1 was delivered by the silicon‐carbon nanocomposite electrode, and the capacity still remains as high as 1018 mAh g −1 after 500 cycles, while the Columbic efficiency is higher than 99%. The inexpensive, effective, and scalable fabrication of porous silicon‐carbon nanocomposite spheres possessing a 3D interlinked network could establish a basis for developing high energy density anode materials to be used in next‐generation LIBs.