Double-carbon protected silicon anode for high performance lithium-ion batteries

• Published in: Journal of alloys and compounds Vol. 812; p. 151848
• Main Authors: Zhu, Linhui, Chen, Yanli, Wu, Changqing, Chu, Ruixia, Zhang, Jie, Jiang, Heng, Zeng, Yibo, Zhang, Ying, Guo, Hang
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 05.01.2020; Elsevier BV
• Subjects: Anodes; Anodic protection; Carbon; Charge transfer; Double carbon-protected; Excellent cyclic property; In-situ polymerization; Integrity; Lithium; Lithium-ion batteries; Protective coatings; Reaction kinetics; Rechargeable batteries; Si-based anode; Silicon; Stability; In-situ polymerization; Double carbon-protected; Excellent cyclic property; Si-based anode
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2019.151848

Undoubtedly, silicon/carbon composites are one of the most promising anode classes for lithium-ion battery. However, they still suffer from poor cycle performance despite the introduction of carbon phase, which is usually expected to inhibit the volume expansion of Si phase and meanwhile enrich the electrode conductivity, improving the cycle stability. Here, a double-carbon protected silicon anode was designed and successfully synthesized through the liquid coating and in-situ polymerization method. In this structure, the primary seamless carbon layer make Si NPs maintain a close contact to conducting carbon, so that inserted Li+ could fully react with Si, improving the utilization of active materials. The secondary carbon skeleton could help to maintain the mechanical integrity of the structure and meanwhile enrich the charge transfer channels. The structural advantages enhance the mechanical integrity and electrochemical kinetics during cycling, that lead to superior electrochemical Li+ storage performance. The resulting double-carbon protected silicon anode demonstrates a high specific capacity, long-term stability (1919 mAh g−1 at 0.5 mA g−1, 90% retention after 400 cycles (vs. the capacity of second cycle)) and outstanding rate capability (1170 mAh g−1 at 2 A g−1). •Simple liquid coating and in-situ polymerization is used in this article.•Carbon source involved in the experiment is low-cost.•There are two different carbon phase in the Si@C@PC composite.•Excellent cyclic property is obtained for the double-carbon protected Si anode.