A review of silicon/carbon composite anode materials with an encapsulated structure for lithium-ion rechargeable batteries

Si/C composites as anode materials have received increasing attention owing to their high energy density, low self-discharge efficiency and long cycle life in lithium-ion rechargeable batteries (LIBs). However, severe volume expansion and an unstable solid electrolyte interface in the lithiation-delithiation of silicon are major obstacles to their commercial applications. The production methods, electrochemical performance, specific capacity and cycling performance of Si/C composite anode materials are summarized, and indicate that by forming an encapsulated structure, the Si volume expansion and cracking of the carbon layer during lithiation can be greatly avoided and the cycling stability of LIBs can be effectively improved. Si encapsulated by carbon is a promising strategy for preparing Si-based anode materials to replace graphite for high-capacity LIBs.