Dual Modulated SiO Particles by Graphene Cord and Si/SiO2 Composite for High‐Performance Lithium‐Ion Battery Anodes

• Published in: Advanced materials interfaces Vol. 9; no. 10
• Main Authors: Zhao, Hongda, Ding, Xuli, Zhang, Ning, Chen, Xiaojing, Xu, Jiahao, He, Pengfei
• Format: Journal Article
• Language: English
• Published: Weinheim John Wiley & Sons, Inc 01.04.2022; Wiley-VCH
• Subjects: Anodes; Chemical vapor deposition; Electrical resistivity; Electrochemical analysis; Electrode materials; Flexibility; Fragility; Grain boundaries; Graphene; graphene cord; lithium storage; Lithium-ion batteries; Phase change; phase change of SiO; Phase transitions; Reaction mechanisms; sepia‐like structure; Silicon dioxide; silicon monoxide; Wetting
• ISSN: 2196-7350; 2196-7350
• DOI: 10.1002/admi.202102489

To dispose the fragility and poor conductivity problems of SiO‐based anode materials, a “phase change mediation combined with cord reinforcing” concept is proposed, in which graphene cord is in situ fabricated combined with Si and SiO2 nanodomains generated in the SiO matrix via chemical vapor deposition. Being the fabricated composite, graphene cord not only bridges but also wraps the SiO particles, improving the electrical conductivity and flexibility of the fabricated SiO@Gra anode. Moreover, the increased SiO2 regions in the Si/SiO matrix alleviate volume change and release the strain for Li+ insertion, enhancing the tenacity of the SiO electrode according to the phase transformation flexibility mechanism. Besides, the grain boundaries and interfaces among the Si/SiO2/SiO regions contribute to additional Li+ storage and pledge more channels for Li+ transfer and electrolyte wetting. The merit of Si/SiO2/SiO synergistically contributes to the ascendant electrochemical performance of the SiO anodes. The as‐fabricated SiO@Gra anodes deliver a high reversible capacity of 1127 mAh g−1 at 0.2 A g−1 with 87% capacity retention after 200 cycles. The proposed phase change and cord reinforcing not only deepen the understanding of the electrochemical reaction mechanism of Li+ in SiO, but also inspire a rational design tactic for advanced lithium‐ions batteries. An octopus‐shape SiO@Gra composite with graphene cord in situ fabricated is realized via chemical vapor deposition method combined with a simple but effective temperature‐mediation strategy. A “phase change mediation combined with cord reinforcing” concept is proposed to dispose the fragility and poor conductivity problems of SiO‐based anode materials. The as‐fabricated SiO@Gra anodes exhibit superior electrochemical properties.