A strategy to deposit nano metals in multi-layer graphene for scalable synthesis of high performance anode materials in lithium ion battery

A facile and scalable method for deposition of nano metals in multi-layer graphene is developed. Nano Sn-graphene hybrid (Sn@Gr) is prepared for high performance anode in lithium ion battery, via the in-situ deposition of Sn nanoparticles in multi-layer graphene through pyrolysis of glucose and tin chloride in molten salts with addition of ammonium chloride. The synthesized Sn@Gr demonstrates a lithiation capability (1000 mAh g⁻¹ of Sn@Gr) higher than the dual lithiation capacity from graphite and Sn. The in-situ formed Sn nanoparticles not only expand the interlayer space of the multi-layer graphene to increase the lithiation capacity of graphene but also bridge the graphene sheets to enhance the electrical conduction in longitudinal direction of graphene sheet, leading to the excellent rate performance. The mechanical toughness of the graphene coupled with the firm connection between nano-Sn and graphene sheet contributes the enhanced durability of the Sn@Gr anode. Both lithiation and delithiation capacities of 671 mAh g⁻¹ remain even after 700 cycles at a current of 800 mA g⁻¹. A stable rate capacity as high as 606 mAh g⁻¹ has been achieved at a current of 1000 mA g⁻¹. © 2017 Elsevier B.V.