Three-dimensional carbon-coated Si/rGO nanostructures anchored by nickel foam with carbon nanotubes for Li-ion battery applications

A nanostructured silicon (Si) electrode has shown great potential as a lithium-ion battery (LIB) anode because it has a charge storage capacity ten times more than that of conventional graphite; however, practical applications of Si-based anodes have been severely hindered due to their poor cyclability and low intrinsic electrical conductivity. Here we develop a novel binder-free Si-based anode through the encapsulation of Si nanoparticles (Si NPs) with carbon cloth and reduced graphene oxide (rGO), where carbon nanotubes (CNTs) rooted from a nickel foam result in a strong connection mechanically and electrically between active materials and current collectors. In the resulting architecture, a dense cellular carbon cloth from carbonization of poly(methyl methacrylate) (PMMA) on Si surfaces can improve the electrical conductivity and accommodate the volume change, whereas rGO networks provide additional mechanical strength to maintain the integrity of electrodes. The newly designed nanostructure exhibited a high reversible capacity up to 2700 mAh g(-1) at 0.05 C (130 mA g(-1)) and 70% of capacity retention (up to 1311 mAh g(-1)) at 2.6 A g after 900 cycles. (C) 2015 Elsevier Ltd. All rights reserved.