Interfacial engineering of Si/multi-walled carbon nanotube nanocomposites towards enhanced lithium storage performance

Investigation of interfacial reactions between Si and multi-walled carbon nanotubes (MWCNTs) and their effect on lithium storage properties has not yet been reported. Herein, deposition of amorphous Si nanoparticles on MWCNTs is reported by a low pressure chemical vapor deposition. The structural and interfacial evolutions upon high-temperature annealing are systematically investigated, and the results show that Si nanoparticles gradually react with MWCNTs from interfacial regions by forming SiC bonds with increasing annealling temperature, and Si nanoparticles completely convert into SiC by reacting with the interfacial carbon atoms at 1200 °C. When examined as anode materials for lithium ion batteries, the Si/MWCNTs with partial interfacial SiC demonstrate the best lithium storage properties, owing to the robust connections between Si and MWCNTs via a chemical bonding of SiC, which buffers the volume changes during the LiSi alloying-dealloying.