초록 |
Li-ion secondary batteries (LiBs) are the most widely used power source in mobile and portable electronic devices due to their outstanding energy and power density. Many critical issues of LIBs have been extensively discussed such as the high energy density, high durability, low cost, weight, and safety. We show a graphene based nanocomposite materials, composed of uniform sized iron oxide nanoparticles, for high performance LiBs. The iron-oxide/graphene nanocomposite was directly synthesized by heat treatment of a mixture of iron-oleate and graphene. The uniform sized γ-Fe2O3 nanoparticles were homogeneously embedded inside the graphene layers. As anode material in LiBs, the iron-oxide/graphene nanocomposite shows outstanding electrochemical performance because the restacking of the graphene layers and the nanoparticle’s aggregation were prevented by acting as mutual spacers themselves in the nanocomposites. |