Recently,many research works have been reported on graphene as anodes for Li-ion batterys (LIBs).But due to its limited theoretical capacity of 744mAh/g,the up-to-date research attempts begin to focus on improving the capacities by compounding some other materials,such as metal1,metal oxide2,or even semiconductors3.Among them,Sn breaks out for its high theoretical capacity of 992mAh/g and superior conductivity,which are beneficial for the total capacity improvement in the graphene/Sn composite anode.Moreover,acting as the buffer layer,graphene can help to overcome the shortcomings of Sn electrode material during charge/discharge processes,such as the enormous volume expantion4.Some groups have synthesized the Graphene/Sn composites anodes exhibiting enhanced reversible lithium storage1,5,although there is still a long distance to reach the theoretical capacity of Sn (992mAh/g).In this work,the Graphene/Sn (G-Sn) nanocomposite was synthesized by a simple method with the common chemical reducing agent of NaBH4.The high pressure Teflon reator was used during the synthesis to improve the material’s crystal quality.The SEM images show that Sn particles well disperse on reduced graphene sheets with the size of less than 10 nm.An improved capacity compared to the commercial graphite even graphene was achieved by measuring the electrochemical performances of the graphene/Sn nanocomposite electrode.Related mechanisms during the Li-ion insertion/extraction in the composite electrode were alsostudied.