Encapsulating silicon nanoparticles into N-doped carbon film as a high-performance anode for lithium ion batteries

Abstract

A flexible strategy is to exploit encapsulating Si nanoparticles into N-doping carbon film (Si-NC) that can effectively localize the Si nanoparticles, thereby solving the problem of serious volume change during cycling as well as facilitating the fast diffusion of Li[Formula: see text], and thus achieving improved anode performance. A maximum capacity of 883.1[Formula: see text]mAh[Formula: see text]g[Formula: see text] at the current density of 100[Formula: see text]mA[Formula: see text]g[Formula: see text] after 50 charge and discharge processes is achieved for Si-NC. Even at a large current density of 2000[Formula: see text]mA[Formula: see text]g[Formula: see text], a specific capacity of 415[Formula: see text]mAh[Formula: see text]g[Formula: see text] is maintained. Moreover, the charge capacity can still almost recover the initial capacity as the current density is reverted to 100[Formula: see text]mA[Formula: see text]g[Formula: see text], indicating that Si-NC has a superior rate performance in lithium storage. This facile synthesis route provides a new perspective to produce Si/C composite at a low cost and large scale with good electrochemical performance.