A composite with SiOx nanoparticles confined in carbon framework as an anode material for lithium ion battery

A composite with ultrafine SiOx (x = 1.57, around 2 nm) nanoparticles confined in a carbon framework is synthesized by a simple thermopolymerization process and subsequent heat treatment. In the composite, the carbon framework can provide a consecutive network to improve the electrical conductivity of the composite and cushion the volume expansion to prevent the active material peeling from the current collector. The ultrafine SiOx nanoparticles can alleviate mechanical strain and shorten the diffusion/transport distance of lithium ions and electrons. In consequence, the as-synthesized composite delivers a high reversible capacity of 540 mA h g(-1) at a current density of 500 mA g(-1) after 200 cycles. The composite delivers good electrochemical performance, making it a promising candidate for the next-generation high-energy LIBs.