Highly stable SiOx/multiwall carbon nanotube/N-doped carbon composite as anodes for lithium-ion batteries

摘要

Fabricating high-capacity electrode materials with long cycle life is essential to developing high-power energy storage and conversion systems. SiOx is a very attractive anode material for lithium-ion batteries, but both low electronic conductivity and volume effect severely hamper its practical application. In this work, multiwall carbon nanotube (MWCNT) and N-doped carbon are combined to improve the electrochemical properties of SiOx. The synthesized composite (labeled as SiOx/MWCNT/N-doped C) has a network structure, in which MWCNT serves as a highly conductive and porous scaffold facilitating electron and ion transport, while N-doped C improves electric contact between SiOx/MWCNT particles and prevents the physical and electrochemical agglomeration of SiOx. The electrochemical measurement shows that the SiOx/MWCNT/N-doped C exhibits excellent cyclic stability and rate capability. At a current density of 100 mA g(-1), a stable discharge capacity of about 620 mAh g(-1) is achieved and the capacity can be preserved up to 450 cycles. The enhanced conductivity and stable electrode structure should be responsible for the excellent electrochemical performance. (c) 2016 Elsevier Ltd. All rights reserved.