Graphene and Carbon Nanotube Dual-Decorated SiOx Composite Anode Material for Lithium-Ion Batteries

In this study, a three-dimensional graphene- and carbon nanotube (CNT)-decorated SiOx composite material (SiOx-Gr-CNT) was synthesized. The dual carbon components were introduced by a simple one-step method of high-energy ball milling. The corresponding SiOx-Gr-CNT composite electrode exhibited superior lithium storage performance because the graphene and CNT components form a flexible network with high conductivity decorating on SiOx. The network is beneficial for the improvement of the conductivity of SiOx particles. The mechanical flexibility of the graphene and CNT components had a negligible volume effect, which could effectively suppress the volume expansion of SiOx and assist to form a durable solid electrolyte interphase film by separating SiOx particles from the electrolyte. Thus, the electrochemical properties of the corresponding SiOx-Gr-CNT composite electrode were effectively enhanced with a large reversible specific capacity of 1015.1 mA h g(-1), which was maintained at 1046.6 mA h g(-1) after cycling of 100 cycles with a capacity remaining exceeding 100% under a current density of 100 mA g(-)(1). The SiOx-Gr-CNT composite electrode also exhibited outstanding cycling performance under a large current density of 1 A g(-1) with more than 800 mA h g(-1) reversible specific capacity even after 200 cycles. The method used for the combination of the SiOx-Gr-CNT composite anode material is simple and mass productive and thus is promising for practical application.