Dual-Type Si Nanocrystals Embedded Si/SiO x Nanocomposites As a High Capacity Anode Material for Lithium-Ion Battery

Abstract

SiO x -based materials have gained much attention as high capacity materials for lithium-ion battery because of their good cycle performance. However, the commercial use is still limited by their low initial coulombic efficiency as well as complex synthetic method. In this work, we propose a dual-type Si nanocrystal-embedded SiO x nanocomposites using a cost-effective sol-gel reaction of SiO x precursor with commercial crystalline Si particles. This core shell structured high-capacity Li+ storage materials showed a reversible capacity of 1914 mAh g-1 with excellent cycle performance. The SiO x matrix would be helpful in accommodating the volume changes of Si nanoparticles core during cycling. To further improve electrochemical performance, we employed additional carbon coating on the surface of the dual-type silicon nanocrystal-embedded SiO x nanocomposites for sufficient electrical conductivity of active materials. The resulting carbon coated anode materials showed improved cycle performance with capacity retention of 80.3% after 100 cycles. The microstructure and electrochemical properties of the dual-type silicon nanocrystal-embedded SiO x nanocomposites will be discussed in more detail.