文摘
Nanotechnology and carbon coating have been applied to silicon anodes to achieve excellent lithium-ion batteries, but the exclusive influence of carbon coating on solid–electrolyte interphase (SEI) formation is difficult to exhibit distinctly because of the impurity and morphological irregularity of most nanostructured anodes. Here, we design a silicon nanocone–carbon (SNC-C) composite structure as a model anode to demonstrate the significant influences of carbon coating on SEI formation and electrochemical performance, unaffectedly as a result of pure electrode component and distinctly due to regular nanocone morphology. As demonstrated by morphological and elemental analysis, compared to the SNC electrode, the SNC-C electrode maintains a thinner SEI layer (∼10 nm) and more stable structure during cycling as well as longer cycle life (>725 cycles), higher Coulombic efficiency (>99%), and lower electrode polarization. This well-defined structure clearly shows the interface stability attributed to carbon coating and is promising in fundamental research of the silicon anode.
