Direct plasma deposition of amorphous Si/C nanocomposites as high performance anodes for lithium ion batteries

Abstract

Plasma reactions are very effective in the preparation of both silicon and carbon materials. However, Si/C composites, which are highly attractive as the anode material in lithium ion batteries, are difficult to be prepared using plasma due to the strong tendency of silicon carbide (SiC) formation. Here we effectively inhibit the SiC formation by generating reactive Si and C species in separated plasma zones and by using a solid graphite carbon precursor. Homogeneous Si/C nanocomposites with excellent lithium storage performance are obtained by one step plasma deposition at room temperature, which retain a high capacity of 1760 and 1460 mA h g⁻¹ after more than 400 cycles at a charge/discharge rate of 2.0 and 4.0 A g⁻¹, respectively.