Lithium silicates nanodots-decorated SiOx-C/graphene anode material with enhanced rate performance for lithium ion batteries

• Published in: Journal of alloys and compounds Vol. 924; p. 166521
• Main Authors: Li, Zhaolin, Zhao, Hailei, Tao, Xin, Yang, Yaozong, Wang, Jie, Yang, Zhao
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 30.11.2022; Elsevier BV
• Subjects: Anode; Anodes; Degradation; Electrochemical performance; Electrode materials; Electrodes; Electron transport; Graphene; Heat treatment; Lithium; Lithium ion battery; Lithium silicate; Lithium-ion batteries; Local current; Low conductivity; Reaction kinetics; Rechargeable batteries; Silicates; Silicon suboxide; Sol-gel processes; Synergistic effect; Lithium silicate; Electrochemical performance; Lithium ion battery; Silicon suboxide; Anode
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.166521

Silicon suboxide (SiOx, 0 <x < 2) is regarded as one of the most prospective anode materials for high-energy-density lithium-ion battery. However, its large-scale application is impeded due to the sluggish electrode reaction kinetics and fast capacity degradation arising from its low conductivity and severe structural degradation. Herein, we reported a lithium silicate (LS) nanodots decorated SiOx-C/graphene material prepared by a facile sol-gel approach with subsequent heat-treatment. The highly-dispersed LS nanodots and graphene sheets provide the fast Li-ion and electron transport for SiOx electrode and therefore enhancing the electrode reaction kinetics of SiOx-C@LS/graphene (SCL-G) electrode. Meanwhile, the highly-conductive network homogenizes the local current density and electrode reactions, which renders homogeneous volume variation and mitigates structural stress of SiOx, resulting in excellent structural durability during repeated cycles. Owing to the synergistic effects, the SCL-G electrode delivered a reversible capacity of 400 mAh g−1 at 0.5 A g−1 without obvious capacity degradation for 200 cycles. •A fast Li-ion and electron transport network is well-constructed.•The chemical combination between SiOx and graphene ensures the structural stability.•Superior rate capability and excellent cycling performance are delivered.