A self-sacrifice template strategy to fabricate yolk-shell structured silicon@void@carbon composites for high-performance lithium-ion batteries

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 351; pp. 103 - 109
• Main Authors: Mi, Hongwei, Yang, Xiaodan, Li, Yongliang, Zhang, Peixin, Sun, Lingna
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-11-2018
• Subjects: Lithium-ion batteries; Polyethyleneimine (PEI); Self-sacrifice template; Yolk-shell structure; Lithium-ion batteries; Polyethyleneimine (PEI); Yolk-shell structure; Self-sacrifice template
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2018.06.065

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•A self-sacrifice template strategy is proposed to fabricate yolk-shell structured Si@void@C composites.•Polyethyleneimine (PEI) is used as a self-sacrifice intermediate layer to form a satisfactory void space during pyrolysis.•The Si@void@C composites demonstrate ideal cycle stability as lithium-ion batteries anode.•The work provides a convenient, environmental-friendly and low-cost approach for large-scale production.
Due to its high specific capacity, silicon (Si) is considered as the most promising alternative anode material for high energy density lithium-ion batteries, but it suffers from dramatic volume expansion during the charge/discharge process. Fabricating yolk-shell structure is regarded as an essential way to improve the conductivity and cycle stability of Si-based anode. In this work, we proposed a “self-sacrifice template strategy” by using polyethyleneimine (PEI) to form the void space during carbonation without acid or base etching, which was different from the colloidal templates method. The yolk-shell structured silicon@void@carbon (Si@void@C) composites were synthesized to enhance cycle stability for lithium-ion batteries, which delivered a capacity of 854.1 mAh·g−1 at the current density of 0.2 A·g−1 after 200 cycles. Our work is also expected to be extended to the synthesis of other yolk-shell structured composites and the application in energy storage, catalysis, biomedicine and other fields.