One-Step Synthesis of SiOx@Graphene Composite Material by a Hydrothermal Method for Lithium-Ion Battery Anodes

SiO x @graphene composite material was prepared by a one-step hydrothermal method and was used as a high-performance anode material for lithium-ion batteries. Graphene decoration on SiO x particles can help to improve the conductivity, relieve the volume effect thanks to the excellent mechanical property of graphene, and form a stable solid electrolyte interphase layer profit from the separation of SiO x particles from electrolyte. On the other hand, Li-oxide and Li-silicate can be generated due to the reaction of Li + with Si and O elements during the process of Li + intercalation and can accommodate the volume changes, which is beneficial for the cyclic performance. The corresponding SiO x @graphene composite electrode shows outstanding cyclic performance with high reversible specific capacity at the second cycle as 1541.3 mA h g –1 and still maintains 1516.6 mA h g –1 after 110 cycles with retention as high as 98.4%. The SiO x @graphene composite electrode also has an outstanding rate performance with a reversible specific capacity of more than 800 mA h g –1 under a current density of 1 A g –1 . The method used in this work is simple, which is very promising in high-capacity lithium-ion battery field.