One-Step Electrodeposition of Layer by Layer Architectural Si-Graphene Nanocomposite Anode of Lithium Ion Battery with Enhanced Cycle Performance

One step electrodeposition is applied to prepare Si-Graphene (SiG) composites from Graphene(G)-SiCl4 -[BMP] tf(2)N ionic liquid. The SiG composites have shown an alternate layer-structure of Si and graphene caused by alternate processes of Si reduction and graphene adsorption on the electrode, which is confirmed by the regular current pulsation in the chronoamperometric curves during the whole electrodeposition process. The SEM and TEM morphologies indicate that each layer is about 120 nm thickness for the SiG3 composites electrodeposited from the 0.1852 mol.l(-1) Graphene(G)-SiCl4 -[BMP] tf(2)N ionic liquid, in which Si particle size is about 80-110 nm closely stick on 4-5 layers of graphene with a molar ratio of Si and C of 4.57: 1. SiG3 anode displays a specific capacity of 1378 mAh.g(-1) at the initial cycle, and 1083 mAh.g(-1) at the end of 400 cycle (retention of 78%) at 4 A.g(-1), as well as 988 mAh.g(-1) at 8A.g(-1), showing a good cycle life and rate performance. The layer-structured SiG anode significantly improve the conductivity and electrochemical performances of Si anode. The research provides a feasibility for electrodeposition preparation of layer-structured materials, especially for semiconductor-based alloys, graphene-based alloys in large-scale. (C) The Author(s) 2018. Published by ECS.