Few-layer methyl-terminated germanene–graphene nanocomposite with high capacity for stable lithium storage

Abstract Germanene, as a cousin of graphene, has shared increasing attention in recent years. There have been abundant theoretical and experimental reports on the synthesis and physicochemical properties of germanene, but few experiments have investigated the energy storage properties. Herein, this study reports the electrochemical properties of GeCH3, a methyl terminated germanene, as anode materials for lithium-ion batteries (LIBs). First, few-layer GeCH3 nanosheets were prepared by liquid-phase exfoliation. Then to further explore the electrochemical lithium storage potential of GeCH3 nanosheets, sandwiched GeCH3/rGO nanocomposites were prepared by adding rGO as a conductive agent and stabilizer through a simple ultrasonic wet dispersion mixing process. The resulting nanocomposite exhibited a remaining capacity of 1058 mAh g−1 after 100 cycles at 0.2 A g−1, indicating that GeCH3 nanocomposite is a promising high energy density anode material. This encouraging result may shed light on the application of germanene in LIBs.