Effects of surrounding confinements of Si nanoparticles on Si-based anode performance for lithium ion batteries

We report herein the effects of various surrounding confinements of Si nanoparticles on the electrochemical performance of Si nanoparticles based anode for lithium ion batteries (LIBs). Three different types of surrounding confinements are incorporated onto or around the surface of Si nanoparticles: Si nanoparticles-embedded carbon nanofibers (Si@CNF) via electrospinning, carbon nitride encapsulated Si nanoparticles with core/shell structure (Si@CND), and binder enriched Si nanoparticles-based anode (Si@RBD). Morphology and microstructure of the samples are characterized using X-ray diffractometry, scanning electron microscopy, transmission electron microscopy, and the results were discussed in relation to the electrochemical performances. It is found that Si@CNF which has conducting hard surrounding confinements and Si@RBD exhibited high reversible specific capacity of 620 mA hg(-1) and 1200 mA hg(-1), up to 30th cycle, respectively. Meanwhile, Si@CND that has mechanically hard but poor electrical conductivity exhibits low specific capacity compared with the other two samples. (C) 2010 Elsevier Ltd. All rights reserved.