Ultrafine Nickel‐Nanoparticle‐Enabled SiO2 Hierarchical Hollow Spheres for High‐Performance Lithium Storage

Abstract

The high theoretical capacity and natural abundance of SiO 2 make it a promising high‐capacity anode material for lithium‐ion batteries. However, its widespread application is significantly hampered by the intrinsic poor electronic conductivity and drastic volume variation. Herein, a unique hollow structured Ni/SiO 2 nanocomposite constructed by ultrafine Ni nanoparticle (≈3 nm) functionalized SiO 2 nanosheets is designed. The Ni nanoparticles boost not only the electronic conductivity but also the electrochemical activity of SiO 2 effectively. Meanwhile, the hollow cavity provides sufficient free space to accommodate the volume change of SiO 2 during repeated lithiation/delithiation; the nanosheet building blocks reduce the diffusion lengths of lithium ions. Due to the synergistic effect between Ni and SiO 2, the Ni/SiO 2 composite delivers a high reversible capacity of 676 mA h g−1 at 0.1 A g−1. At a high current density of 10 A g−1, a capacity of 337 mA h g−1 can be retained after 1000 cycles.