Preparation of ternary hierarchical silicon/reduced graphene oxide/carbon composites as anodes for lithium–ion batteries

• Published in: Journal of alloys and compounds 2019-07, Vol.793, p.433-445
• Main Authors: Wu, Yi–Shiuan, Yang, Chun–Chen, Wu, She–Huang, Wu, Zong–Han, Wei, Chao−Nan, Yang, Min–Yen, Lue, Shingjiang Jessie
• Format: Article
• Language: English
• Subjects: Adhesives; Anode effect; Ball milling; Batteries; Butadiene; Carbon; Carbon–coated copper foil; Carboxymethyl cellulose; Coated electrodes; Composite materials; Copper; Dual–carbon matrix; Electrochemical analysis; Electrode materials; Graphene; Ion transport; Lithium ions; Lithium–ion batteries; Metal foils; Microspheres; Nanoparticles; Polyethylenes; Polymer matrix composites; Polystyrene resins; Polystyrene sphere template–assisting; Rubber; Separators; Silicon; Spray drying; Synergistic effect
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2019.04.168

Silicon/reduced graphene oxide/carbon (Si/rGO/C) composite material prepared with a carboxyl methyl cellulose and styrene butadiene rubber (CMC + SBR) hybrid binder is successfully synthesized, characterized, and evaluated as a composite anode for lithium–ion batteries (LIBs). The porous Si/rGO/C composite microspheres with interior meso–pores are obtained by encapsulating Si–based nanoparticles into the rGO/C dual–carbon matrix via self–assembling, ball milling, polystyrene sphere (PSS) template–assisting, and spray drying techniques, which facilitate a fast electron and Li+ ion transport, and mitigate Si pulverization. Compared with bare copper (Cu) foil, as–prepared Si/rGO/C composite electrode based on a carbon–coated Cu (C–Cu) foil assembled with a polyethylene (PE) separator exhibits better rate capability, in particular, at high rates, and a capacity increases to ca. 6–10%. By cycling at 400 mA g−1 for 500 cycles, the Si/rGO/C/C–Cu composite electrode with a capacity retention (CR%) of ∼75% and Coulombic efficiency (CE%) of ∼99.7% retains a higher specific capacity of ∼602 mAh g−1 than that on bare Cu foil (∼314 mAh g−1), which is comparable to those reported in the literature. The synergistic effect of the hierarchical composite anode material together with highly adhesive and electrolyte−hydrophilic C–Cu foil results in much better electrochemical performance as a promising LIB anode. [Display omitted] •Si/rGO/C composite with a CMC + SBR hybrid binder is synthesized as a LIB anode.•The microspheres with interior meso–pores facilitate fast e– and Li+ transports.•The Si/rGO/C composite coated on C–Cu foil exhibits a better C–rate capability.•The Si/rGO/C/C–Cu electrode retains a CR% of ∼75% at 400 mA g−1 for 500 cycles.