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

SiOx@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 SiOx 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 SiOx 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 SiOx@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 SiOx@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.