包覆结构Si/C复合负极材料研究进展

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

  • 摘要: 以包覆结构Si/C复合材料作为负极的锂离子电池(LIBs)具有能量密度高、自放电效率低、循环寿命长等特点。然而,锂在硅中插入/脱出过程的体积膨胀和固体电解质界面膜(SEI)的不稳定性,阻碍了硅的商业化应用。本文通过对近年来新型包覆结构Si/C复合负极材料的构筑方法、电化学性能、比容量和循环性能进行分析和研究,发现包覆结构Si/C复合负极材料不仅可以缓解硅在锂化过程中的体积膨胀和炭层破裂,而且可以有效提高LIBs循环稳定性。因此,Si/C复合材料有望取代石墨成为高容量LIBs的主要负极材料。

     

    Abstract: 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.

     

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